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Author Topic: Contact Spray Adhesive, a simple question.  (Read 1859 times)

Online Avaiojet

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Contact Spray Adhesive, a simple question.
« on: June 24, 2017, 02:41:55 PM »
Has anyone ever used the 3M General Purpose 45 contact adhesive from an aerosol can to sheet foam core wings?

Thanks in advance.

CB

















Alpha Mike Foxtrot.

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"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

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Offline Jim Carter

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Re: Contact Spray Adhesive, a simple question.
« Reply #1 on: June 25, 2017, 08:20:53 AM »
 :)  Yep!  I've used it on a couple of projects.  Haven't had any problems of note  :).

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Re: Contact Spray Adhesive, a simple question.
« Reply #2 on: June 25, 2017, 10:56:52 AM »
:)  Yep!  I've used it on a couple of projects.  Haven't had any problems of note  :).

Jim,

You use it on foam wings? The 3M 45?

My test piece is sitting in the FL sun.

CB
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Dan McEntee

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Re: Contact Spray Adhesive, a simple question.
« Reply #3 on: June 25, 2017, 11:23:11 AM »
   If you know that 3M-77 has been used successfully, is an accepted method and is still available, why would you want to vary from that method? 3M makes all kinds of spray contact adhesives that are meant for different purposes and no real need to test them all if you know that one particular product does the job. Their Spray Mount Adhesive is great for applying friskets and paint masks, but is essentially the same adhesive that is on Post-It-Notes. It would be a shame to get cans mixed up and try skinning a wing with that stuff. I have seen guys successfully skin R/C sail plane wings with 3M transfer adhesive tape. They would sit out baking in the sun at contests and I never heard of any failures with it. The new generations of thinned epoxy and vacuum bagging methods came along and became the normal application method especially as aircraft performance increased. If you know what works, why try to reinvent the wheel? Just to save a few pennies or even a buck or two? What's your airplane, and time to construct it worth?
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Online Avaiojet

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Re: Contact Spray Adhesive, a simple question.
« Reply #4 on: June 25, 2017, 12:19:22 PM »
   If you know that 3M-77 has been used successfully, is an accepted method and is still available, why would you want to vary from that method? 3M makes all kinds of spray contact adhesives that are meant for different purposes and no real need to test them all if you know that one particular product does the job. Their Spray Mount Adhesive is great for applying friskets and paint masks, but is essentially the same adhesive that is on Post-It-Notes. It would be a shame to get cans mixed up and try skinning a wing with that stuff. I have seen guys successfully skin R/C sail plane wings with 3M transfer adhesive tape. They would sit out baking in the sun at contests and I never heard of any failures with it. The new generations of thinned epoxy and vacuum bagging methods came along and became the normal application method especially as aircraft performance increased. If you know what works, why try to reinvent the wheel? Just to save a few pennies or even a buck or two? What's your airplane, and time to construct it worth?
    Type at you later,
     Dan McEntee

Dan,

The #77 3M spray adhesive had some chemical changes to it years back. This is why it went to the wayside. It does not work as well as it once did which is one of the reasons guys opted for other methods.

It's a biplane, a handful. I'm weighing possibilities to make my work easier and hope the result lasts with my choice.

I also think Epoxy would be heaver than a spray adhesive. I'm looking into that.

What have you used on your foam wings?

CB

Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Paul Smith

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Re: Contact Spray Adhesive, a simple question.
« Reply #5 on: June 25, 2017, 01:50:37 PM »
The last (and only) person I knew who built a plane with 3M 77 said it fell apart due to heat from the sun.  
« Last Edit: June 25, 2017, 03:44:13 PM by Paul Smith »
Paul Smith

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Re: Contact Spray Adhesive, a simple question.
« Reply #6 on: June 25, 2017, 02:17:24 PM »
I last (and only) person I knew who built a plane with 3M 77 said it fell apart due to heat from the sun. 

Yes, 3M 77 is no longer a useful adhesive which can me trusted for sheeting foam wing cores.

However, from many years ago when the product was better, I still have two 40-45 size pattern ships and a set of foam cores, sheeted with 1/16" balsa using 3M 77 aerosol can adhesive.

No separations anywhere, still perfect, but that was then and this is now, so they say.

There's more written on sheeting foam wings than one could believe.

CB
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Online Fredvon4

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Re: Contact Spray Adhesive, a simple question.
« Reply #7 on: June 25, 2017, 02:24:42 PM »
I have not yet balsa covered a foam core wing... but if I did, I would follow Bob Hunts advice to the letter...

That said, it sounds to me ( from these pages) the better method involves well prepped skins, pre coated on the adhesive side with (usually) a coat or two of dope to prevent deep saturation of the adhesive into the dry porous balsa.

Then some variant of a thin finishing resin like ZAP Z-Poxy, or APC E-Z Lam  that is skimmed very thin and maybe even Toilet paper rolled to remove any excess...then pressed in a good former

I tend to think water based is fraught with properly drying and warping problems.

The meager experience I have with ANY Contact adhesive is a registering/alignment nightmare

and in my mind any contact adhesive that CAN be re-positioned is not the right glue for the job

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Re: Contact Spray Adhesive, a simple question.
« Reply #8 on: June 25, 2017, 04:32:59 PM »
My original Post and question was a simple one. Here it is again:

Quote
Has anyone ever used the 3M General Purpose 45 contact adhesive from an aerosol can to sheet foam core wings?

Thanks in advance.

CB

I was just curious about the long term application and results of this particular product used on "model airplane foam wings."

I recently used the product to apply corner blocks and framing around two bathroom mirrors, one being over 8' in length and about 45" in height.

This would be hard wood attached to glass. Couple of months and nothing has come apart, but it's not like being out under the sun on a hot day.

Sure, Epoxy might be the way to go, but it's a bit more work and more time consuming. And I believe it may be a tad heavier? Not sure about that?

I'm familiar with the Epoxy, weighted down overnight method. I also have experience sheeting foam wings using the outdated 3M 77 adhesive.

I'm just doing research on one particular product. 3M 45.

Thank you for the replies.

CB

Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Dan McEntee

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Re: Contact Spray Adhesive, a simple question.
« Reply #9 on: June 25, 2017, 05:50:38 PM »
Dan,

The #77 3M spray adhesive had some chemical changes to it years back. This is why it went to the wayside. It does not work as well as it once did which is one of the reasons guys opted for other methods.

It's a biplane, a handful. I'm weighing possibilities to make my work easier and hope the result lasts with my choice.

I also think Epoxy would be heaver than a spray adhesive. I'm looking into that.

What have you used on your foam wings?

CB


.


    Can you document the changes or is that hear say? There are two varieties of 3M-77, and one is 3M-Super 77, that may be the difference. Maybe you should be contacting 3M??? If some one had a bad experience recently there is no guarantee they did it correctly either, and there are other reasons that could cause a failure. I used 3M-77 on a few foam wings several years ago with good results but have been doing built up ever since. I have one or two airplanes I want to do before too long that are foam cores, and will cross that bridge when I get there. If you used 3M-77 back in the day, that wasn't the only method back then. What did you use before that? Why not use what you KNOW works for your "experience" and use that and not take the risk? If you have the "experience" to do it one way, I would be wary of things you read on the internet.
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Online Avaiojet

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Re: Contact Spray Adhesive, a simple question.
« Reply #10 on: June 25, 2017, 06:31:56 PM »
.


    Can you document the changes or is that hear say? There are two varieties of 3M-77, and one is 3M-Super 77, that may be the difference. Maybe you should be contacting 3M??? If some one had a bad experience recently there is no guarantee they did it correctly either, and there are other reasons that could cause a failure. I used 3M-77 on a few foam wings several years ago with good results but have been doing built up ever since. I have one or two airplanes I want to do before too long that are foam cores, and will cross that bridge when I get there. If you used 3M-77 back in the day, that wasn't the only method back then. What did you use before that? Why not use what you KNOW works for your "experience" and use that and not take the risk? If you have the "experience" to do it one way, I would be wary of things you read on the internet.
    Type at you later,
    Dan McEntee

The documentation is "hear say." You can find it at RCU. There's a Thread with plenty of friendly replies. Forums, some of the comments are true, some is hear say and some are not so nice. That's just the way it is.

I never sheeted a foam wing with any other adhesive than the 3M 77. I have no experience using Epoxy, but that's easier than contact adhesives, so no problem there.

You know more about the 3M 77 than I do, I didn't know there were types. I haven't used it in years.

A home builder told me to use the 3M 45 for the bathrooms.

Yes, because I'm comfortable sheeting with contact adhesives I would like to stay with that method. Also, I don't have to wait overnight to do things. Like the LE and TE. I'm not doing a Bob Hunt LE wrap although I really considered it so I have all the 3/8" balsa LE's and TE's to do also.

I've said this plenty of times, I really don't like building wings so I want to start it and get it over as fast as I can.

Another thing. The wings will be removable. If I screw up one it can be easily replaced.

Thanks for the reply and interest.

CB
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Online Brett Buck

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Re: Contact Spray Adhesive, a simple question.
« Reply #11 on: June 25, 2017, 08:33:40 PM »

I also think Epoxy would be heaver than a spray adhesive. I'm looking into that.

   No. Epoxy is *drastically* lighter, on the order of ounces on a 10 ounces total weight. And it is far more stable over time and allows much more working time.

    Forget spray adhesive of any type, it is notorious for lifting after a while (partly due to age and partly due to dope solvents/outgassing), and, it doesn't really take full advantage of the natural jigging that you get with the cradles. If you get warp while sticking the wood down with contact cement of any sort, sticking it in the cradles and weighing it down doesn't really fix it. With epoxy, it is more-or-less guaranteed to be held straight while the bond is forming. And it's not going anywhere afterwards.

     Brett

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Re: Contact Spray Adhesive, a simple question.
« Reply #12 on: June 25, 2017, 08:48:06 PM »
   No. Epoxy is *drastically* lighter, on the order of ounces on a 10 ounces total weight. And it is far more stable over time and allows much more working time.

    Forget spray adhesive of any type, it is notorious for lifting after a while (partly due to age and partly due to dope solvents/outgassing), and, it doesn't really take full advantage of the natural jigging that you get with the cradles. If you get warp while sticking the wood down with contact cement of any sort, sticking it in the cradles and weighing it down doesn't really fix it. With epoxy, it is more-or-less guaranteed to be held straight while the bond is forming. And it's not going anywhere afterwards.

     Brett

Brett,

You took the time to Post and you make a good deal of sense.

 "Forget spray adhesives of any type." OK, I will.

I'll bite the bullet and put in the time for a stiffer and better made wing, well, wings actually.

I'll review Bob Hunt's PDF file on sheeting foam wings. If I can find it?

Thanks for the reply and the interest.

CB

Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Traian Dorin Morosanu

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Re: Contact Spray Adhesive, a simple question.
« Reply #13 on: June 26, 2017, 07:41:25 AM »
3M 77 works great on XPS if you just dust it very lightly. I do not know how it behaves on the white foam. For sure it will eat up the XPS too if you lay the 3M 77 heavy.
If you want a light lamination on white foam there is an alternative to go with epoxy. First after you nix the epoxy then add 50% Isopropyl alcohol in the mix to thin it out. Then use a roller to apply the epoxy. Keep the roller dry as you wet the balsa and apply the epoxy just enough to see the wood wet. If you insist too much on a spot a lot of the Epoxy mix will soak in to the grain and that will make the layout heavy. If it is too wet you can use paper towels to blot out some of the excess.
It will be slower but what is an extra day added to the countless days of work we do to make a competitive model. Use the time when the cores are drying to do something else.

Traian
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Online Brett Buck

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Re: Contact Spray Adhesive, a simple question.
« Reply #14 on: June 26, 2017, 10:09:59 AM »
I did see a guy use one of those low nap 3" rollers and apply the Epoxy that way. Quick.

  That will apply about 100x the amount of glue needed.  The basics have been known since the very early 80's, just read the attachment.

   Brett

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Re: Contact Spray Adhesive, a simple question.
« Reply #15 on: June 26, 2017, 10:48:49 AM »
  That will apply about 100x the amount of glue needed.  The basics have been known since the very early 80's, just read the attachment.

   Brett

Thank you Brett,

And I will.

CB
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

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Re: Contact Spray Adhesive, a simple question.
« Reply #16 on: June 26, 2017, 12:02:47 PM »
The last (and only) person I knew who built a plane with 3M 77 said it fell apart due to heat from the sun.  

Yes I have seen that on several planes, also one other  hint is  DO NOT  spray it in too heavy coats, it WILL distort and melt foam in thick coats,  I have used most every technique you can think of, and  Brush on Southern Sorgum, and  Epoxy  is the best/lightest/most durable,  My way I developed many decades ago is to  brush full strength  dope over the  insides of  the skins used,  Then knock off the raised grain with 400  sandpaper. this makes it smooth and the dope will STOP the punk balsa from sucking up the epoxy or brush on  contact cement.  It will look wet  with only about 1/4 ounce epoxy spread thin, as an example you can put 2 ounces plus , of  epoxy or contact cement on the skins , and the will not look wet, the balsa just sucks up whatever  you pour on.  The lite dope seals the  wood and keeps the  glue on the outside instead of soaking into the balsa

And the heaviest I have ever seen is  core bond

Randy

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Re: Contact Spray Adhesive, a simple question.
« Reply #17 on: June 26, 2017, 01:06:33 PM »
The old style 3M77 doesn't use acetone for the "carrier" and the new stuff does. It will melt the foam if sprayed wet to the foam.
A light mist works because the acetone evaps out of the glue while it falls to the part being sprayed.

That being said, a LOT of guys in sunny CA used the old 3M 77 on sailplane wings to good effect. Like any contact cement, dry to touch on both pieces and dust free is keys to success.

The new 3M77 is still very useful for many things, particularly spraying light composite fabric so it won't unravel, and also sticking it to objects before wetting the fabric out with epoxy.

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Offline Jim Carter

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Re: Contact Spray Adhesive, a simple question.
« Reply #18 on: June 27, 2017, 11:43:24 AM »
Jim,

You use it on foam wings? The 3M 45?

My test piece is sitting in the FL sun.

CB
Man!  I ain't about to come against the "experts" cauz' they're certainly smarter than me, 'fer shur' .... but ..... you're more than welcome to see and inspect or fly any of mine with foam wings!  They "ain't" failed me yet and they still look good!!  The oldest of the bunch is my well raced r/c Quickee 500 with a Rossi 40.  It's about almost 20 years old, never been wrecked and still hauls .....  ;D!!  The newest of the bunch is a profile variant of a plane called the Wild Thing that was used for r/c combat back in the early to mid 90's.  I built it as a control line variant because I had a foam wing left over from back in the day and it hauls on an old OS 15.  Sooooooo .... I say "Yep"! I sprayed the foam then sprayed the wood, let 'em set/cure/dry for about 20 minutes or so then very gingerly applied the wood to the foam.  Trust me they ain't coming apart!!  ;D (leastways not in the same condition they went together  LL~ LL~)  Bottom line I say go fer'it and remember "ya' pays yer money and takes y'er chances!  ;D ;D
« Last Edit: June 27, 2017, 12:05:43 PM by Jim Carter »

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Re: Contact Spray Adhesive, a simple question.
« Reply #19 on: June 28, 2017, 03:58:46 PM »
Bob Hunt's method is by far the best in my opinion.  It really isn't all that complex or time consuming, either.  Have your ducks in a row before you start and it goes rather quickly.  Sets overnight and is ready for the next steps.  as long as you do the scraping off, the weight is very low.
A nats winning RC guy rolls his epoxy with a toilet paper roll instead of scraping, but I prefer Bob's method.
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Re: Contact Spray Adhesive, a simple question.
« Reply #20 on: June 28, 2017, 09:58:18 PM »
Bob Hunt's method is by far the best in my opinion.  It really isn't all that complex or time consuming, either.  Have your ducks in a row before you start and it goes rather quickly.  Sets overnight and is ready for the next steps.  as long as you do the scraping off, the weight is very low.
A nats winning RC guy rolls his epoxy with a toilet paper roll instead of scraping, but I prefer Bob's method.

      If you put a coat of clear nitrate (or Bobby's hair spray which is about the same thing) on the mating surface, it's really not even all that critical how well you squeegee it off, because if you do enough to remove puddles of glue, the net weight gain compared to everything else gets to be negligible, and it's not worth a lot of effort to save 5 grams on a 120 gram wing panel, and certainly not worth risking taking off to much can causing a delamination later.

    I use a Signature Inn room key card (of which I have *many*), with notches about 1/16" wide and deep made with a triangular file every 3/8" to ensure I leave enough on there for a good bond. Compared to contact cement like 3M77 (or the foam-safe equivalent), HomeSafe, or Corebond, the epoxy weight just isn't significant. As with Randy, I had good enough results with Southern Sorghum, but epoxy is easier, lighter, and overall, better.

   A different interesting argument is what type/brand of epoxy you should use. I like West Systems or EZ-Lam, and EZ-Lam has by far the best working time of anything I have tried. I *don't* recommend finishing epoxy, even though it's nice and thin -  it gets too brittle and all the different types I tried self-heated to the point it cut the working time drastically.

     Brett

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Re: Contact Spray Adhesive, a simple question.
« Reply #21 on: June 28, 2017, 11:08:19 PM »
  Where do you get EZ-Lam? Is it hobby oriented stuff? I think I can get West Systems products in my area but don't use a whole lot of epoxy products so regular hobby shop stuff is all I keep on hand, and in small amounts  or it all goes bad anyway. I have a set of genuine Lew McFarland cut ( I forget his company name) foam cores for his Spinks Akromaster and that is at the top of my build list. They should be easy, no landing gear clips to worry about or deal with, fuse mounted gear.
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Online Brett Buck

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Re: Contact Spray Adhesive, a simple question.
« Reply #22 on: June 28, 2017, 11:14:54 PM »
  Where do you get EZ-Lam? Is it hobby oriented stuff? I think I can get West Systems products in my area but don't use a whole lot of epoxy products so regular hobby shop stuff is all I keep on hand, and in small amounts  or it all goes bad anyway.

https://store.acpsales.com/products/2271/ez-lam-epoxy-resin

  It's run by Justin Sparr, former stunt champion (jr or senior). He's also the one behind the carbon/honeycomb forked-end bellcrank (at the behest of David and Jim).
 
    Brett

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Re: Contact Spray Adhesive, a simple question.
« Reply #23 on: June 28, 2017, 11:52:46 PM »
     
   A different interesting argument is what type/brand of epoxy you should use. I like West Systems or EZ-Lam, and EZ-Lam has by far the best working time of anything I have tried. I *don't* recommend finishing epoxy, even though it's nice and thin -  it gets too brittle and all the different types I tried self-heated to the point it cut the working time drastically.

     Brett
I agree about the finish resin in bottles, it's not great. Have you tried the 206 WS slow hardener, Brett, or are you only using the 205 fast hardener? I don't care much for WS laminating resin but their G-flex epoxy in bottles is great for bonding.
The brand of laminating epoxy shouldn't have much effect on pot life. It's whether you get their fast or slow hardener, mixed in proper proportion, and ambient temp, and if you keep the mixed batch in the cup or not.

If you are in a hotter summer setting, you should measure, mix, then pour it out onto a paper plate, so it won't have the tendency to exotherm, AKA, "Go Off". Doing this one little trick makes a huge difference. Then roll on with a 3" x 1/8" nap foam roller, use your slotted card to remove the excess.

The same brand and epoxy and hardener used in the cold winter(maybe not in SoCal), might find you needing to warm the resin and catalyst before even mixing, and then leaving the mix in the cup a few minutes to start the chemical process (depending on if you're using fast or slow cure). Sometimes I use slow cure more in the summer if it is really hot in the shop and fast cure in the winter if its fairly cold. If it's super cold, an electric blanket over the wing cores help with the cure.

I have to wonder why people ever recommend using finish resin when they are clearly laminating parts. It's meant to be used when you need to sand it. Personally, I try to use epoxy so that I will never have to sand it, in general. Plus, if you are wrapping a wing joint with glass, you are clearly laminating the wood with glass, right? I'd say so.... Plastic 4mil sheet from the DIY store works well over the glass and resin back in the weighted beds.

I'm pretty comfortable saying that if the guys that only use 1:1 hobby epoxy bottles each bought a quart kit of EZ Lam or Pro Set epoxy, a gram scale to measure it on, fast and slow catalyst, and some cabosil, they would probably have it a long time and also use it all before it went bad, with far less waste than the bottles. You'll need a stack of paper Dixie cups from the drugstore, and you probably all have stir sticks.
It's so much more versatile, as well as much stronger, and the lower viscosity gains you a better fiber/epoxy ratio.

That's my two cents. The REAL epoxy is very worth the added initial investment and cheaper in the long run by far.

Regards,
Chris

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Online Brett Buck

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Re: Contact Spray Adhesive, a simple question.
« Reply #24 on: June 29, 2017, 12:26:21 AM »
The brand of laminating epoxy shouldn't have much effect on pot life. It's whether you get their fast or slow hardener, mixed in proper proportion, and ambient temp, and if you keep the mixed batch in the cup or not.

If you are in a hotter summer setting, you should measure, mix, then pour it out onto a paper plate, so it won't have the tendency to exotherm, AKA, "Go Off". Doing this one little trick makes a huge difference.

That's what is so good about EZ-Lam compared to the others, it has *much* less tendency to self-heat in the mixing cup than anything else I have tried. Even in the relatively warm weather, there's no reason or need to pour it out in a puddle to keep it cool. That is compared to my previous finishing resin, which would boil in the cup, and any of the slow epoxies (like the grandaddy of them all, HobbyPoxy Formula II) which would warm noticeably and reduce the working time unless you pour it into a puddle.

     Brett

Offline Steve Fitton

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Re: Contact Spray Adhesive, a simple question.
« Reply #25 on: August 11, 2017, 08:04:01 PM »
That's what is so good about EZ-Lam compared to the others, it has *much* less tendency to self-heat in the mixing cup than anything else I have tried. Even in the relatively warm weather, there's no reason or need to pour it out in a puddle to keep it cool. That is compared to my previous finishing resin, which would boil in the cup, and any of the slow epoxies (like the grandaddy of them all, HobbyPoxy Formula II) which would warm noticeably and reduce the working time unless you pour it into a puddle.

     Brett

Using the 60 minute pot life version, I presume?
Steve

Offline Bob Hunt

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Re: Contact Spray Adhesive, a simple question.
« Reply #26 on: August 12, 2017, 01:56:06 PM »
Some have referenced the PDF that is floating around the Internet on my foam wing sheeting method. I don't know who pirated it and put it on a website, but it really doesn't matter; the information is intended for the good of the hobby, and at least they did give me credit...

One thing that I regret in that presentation was how the epoxy glue (Z-Poxy finishing resin) was depicted being applied. I had to use larger "rivulets" of epoxy running chordwise on the example skin in order for the camera to pick up the fact that they were indeed rivulets. In actual practice - and as Brett has indicated - very little epoxy is needed to do the job. You must make certain that there is a thin coating everywhere to prevent the skin from "popping" up later on, but the actual amount of glue needed is miniscule. I do feel that the chordwise rivulets are important to insure that no popping of the skin happens, but those rivulets need only be 1/64-inch or less deep. I use a three-cornered file to notch my 1/32 inch plywood spreader and then after the epoxy is applied and spread over the entire shin, I start at the root and drag the spreader chordwise from front to back and remove the vast majority of material. The spreader is then indexed over one spreader width and the process is repeated in this manner until the entire skin has been "screeted" in this manner.   

I've covered way more than a thousand wings using this method over the nearly 50 years I've been producing covered foam wings. I used to use HobbyPoxy Formula 3 glue, but, alas, they discontinued it. The Z-Poxy works just as well. I've tried dozens of types of adhesives for skinning wings and have found that a thin coat of epoxy is the best and lightest by far over any spray or brush applied contact cement.

Later - Bob Hunt
« Last Edit: August 12, 2017, 08:00:09 PM by Bob Hunt »

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Re: Contact Spray Adhesive, a simple question.
« Reply #27 on: August 12, 2017, 02:14:17 PM »
Some have referenced the PDF that is floating around the Internet on my foam wing sheeting method. I don't know who pirated it and put it on a website, but it really doesn't matter; the information is intended for the good of the hobby, and at least they did give me credit...

One thing that i regret in that presentation was how the epoxy glue (Z-Poxy finishing resin) was depicted being applied. I had to use larger "rivulets" of epoxy running chordwise on the example skin in order for the camera to pick up the fact that they were indeed rivulets. In actual practice - and as Brett has indicated - very little epoxy is needed to do the job. You must make certain that there is a thin coating everywhere to prevent the skin from "popping" up later on, but the actual amount of glue needed is miniscule. I do feel that the chordwise rivulets are important to insure that no popping of the skin happens, but those rivulets need only be 1/64-inch or less deep. I use a three-cornered file to notch my 1/32 inch plywood spreader and then after the epoxy is applied and spread over the entire shin, I start at the root and drag the spreader chordwise from front to back and remove the vast majority of material. The spreader is then indexed over one spreader width and the process is repeated in this manner until the entire skin has bee "screeted" in this manner.   

I've covered way more than a thousand wings using this method over the nearly 50 years I've been producing covered foam wings. I used to use HobbyPoxy Formula 3 glue, but, alas, they discontinued it. The Z-Poxy works just as well. I've tried dozens of types of adhesives for skinning wings and have found that a thin coat of epoxy is the best and lightest by far over any spray or brush applied contact cement.

Later - Bob Hunt

Bob Hunt.

I put up a foam sheeting link, I didn't know I was pirating it? I removed the Post so you feel better.

Here's another modeler that produced a step by step method to sheeting a foam wing. You tube there's a hundred or more.

Avaiojet
« Last Edit: August 12, 2017, 02:31:15 PM by Avaiojet »
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Online Brett Buck

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Re: Contact Spray Adhesive, a simple question.
« Reply #28 on: August 12, 2017, 02:54:36 PM »
Good of the hobby? Then why use the word, "Pirated" I removed the Post. Feel better?

       OK, Sparky, how long are we going to put up with this?

No one has ever, in any way, done more for the "good of the hobby" than Bob Hunt.

     Where is the line, for Christ's sake?  At least shove him back in his hole so the rest of us don't have to suffer.

     Brett



p.s. OH, and additionally - he originally asked about 3M-77 specifically in the first post, but now I see he went back and edited the original post and changed it to 3M-45, making all the subsequent responses off-topic or appearing to be incompetent .

   

     

Offline Bob Hunt

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Re: Contact Spray Adhesive, a simple question.
« Reply #29 on: August 12, 2017, 03:49:48 PM »
Bob Hunt.

I put up a foam sheeting link, I didn't know I was pirating it? I removed the Post so you feel better.

Here's another modeler that produced a step by step method to sheeting a foam wing. You tube there's a hundred or more.

Avaiojet

Cool your jets, Charles. That comment was not aimed at you. Someone took a PDF file that I had done years ago and put it up on the Internet a few years back; long before you came on the scene. Many have referenced it over the years, and I'm not mad at them (or you). I don't even know who it was that posted that information without even asking me lo those many years ago. I have a problem with stuff like that. Having said that, I'm okay with it now because it gets good information out there.

You need to get a thicker skin my friend. We've never had any problems, and I sure am not trying to have one now. Perhaps it is time for me to just fold my tent on this forum and go play guitar. It seems you can't post anything here without you or some other malcontent taking a shot. All I have ever tried to do was help.

Bob Hunt

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Re: Contact Spray Adhesive, a simple question.
« Reply #30 on: August 12, 2017, 03:50:16 PM »

Brett,

I shouldn't even reply to you because you have been one of my major trolls for what, 6 years?

Bob Hunt is a big boy and he can respond for himself, the reply was directed to Bob and no one else. Why you feel you have to answer for anyone or everyone is quite obvious.

Besides, I rethought my reply and edited it.

Bob elected to use the word "pirated." Tells me exactly how he feels about that link being posted.

Knowing how he felt, I edited my reply after rethinking.

Like Robert says, "think" before you reply.

You should try it.
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Online Avaiojet

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Re: Contact Spray Adhesive, a simple question.
« Reply #31 on: August 12, 2017, 03:56:09 PM »
Cool your jets, Charles. That comment was not aimed at you. Someone took a PDF file that I had done years ago and put it up on the Internet a few years back; long before you came on the scene. Many have referenced it over the years, and I'm not mad at them (or you). I don't even know who it was that posted that information without even asking me lo those many years ago. I have a problem with stuff like that. Having said that, I'm okay with it now because it gets good information out there.

You need to get a thicker skin my friend. We've never had any problems, and I sure am not trying to have one now. Perhaps it is time for me to just fold my tent on this forum and go play guitar. It seems you can't post anything here without you or some other malcontent taking a shot. All I have ever tried to do was help.

Bob Hunt

Cool your jets also. Just kidding.

I apologize for Posting that link. Looked like you were talking to me, so I removed the Post.

It's easy for Avaiojet to read Posts incorrectly.

Forgive me.

Didn't know you played guitar. I'm poor with the banjo but enjoy it.

Charles
Alpha Mike Foxtrot.

Owner of CFC Graphics. "Model Airplane Graphics from a Model Airplane Builder."

"No one has ever made a difference by being like everyone else."

Marcus Cordeiro, The "Mark of Excellence," you will not be forgotten.

I look at the Forum as a place to contribute and make friends, some view it as a Realm where they could be King.

"Ya gotta love it when a plane comes together."

Proverb 11.9  "With his mouth the Godless destroys his neighbor..."

"Perhaps the greatest challenge in modeling is to build a competitive control line stunter that looks like a real airplane." David McCellan, 1980.

Offline Peter Nevai

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Re: Contact Spray Adhesive, a simple question.
« Reply #32 on: August 13, 2017, 01:06:24 AM »
I also hate to build wings. Of course everyone who has been in the hobby long enough, knows the evil eye many purists gave anyone who dared to use the material. Too heavy they claimed, too weak, the invention of Beelzebub himself!!. Anywho I have used 77 and the epoxy method and never had issues with either. Never did a side by side weight comparison with Identical wing panels so I cannot comment which is lighter. Of course this was back using the original 77 spray and good old HobbyPoxy. Never vacuum bagged though. With the spray I would roll the cores onto the balsa sheet and used the foam cradles and gallon jugs filled with water on the epoxy method. I just smear on a ton of HobbyPoxy and use an old hotel key card to scrape off excess. NOTE:  Really really messy but it works. Never tried the brush on stuff. The trick with the 77 was you only dusted both surfaces really. You were asking for trouble if you sprayed on a heavier coat. Of course you had to be careful rolling the cores onto the balsa sheets cause once it stuck there was no going back. I remember at the time I thought it was really cool that you could glue balsa sheets together at the edges using regular wood glue and some masking tape, something I would have never thought up on my own. Alas these days seems like the purists have won. No one makes foam wing kits anymore. The hobby has gone full circle, I would have guessed it would be cheaper and easier to produce foam wing kits that all balsa. So as I hate building wings and don't have to tools to build from anything other than a kit, it sucks to be me. :(
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Offline Bob Hunt

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Re: Contact Spray Adhesive, a simple question.
« Reply #33 on: August 13, 2017, 09:30:51 AM »
Hi Peter:

You and I have not seen eye-to-eye on a few things in the past, but on this subject I tend to agree with most of what you have written. The bias against foam wings by the "purists" happened mostly many years ago when foam wings first came on the scene. Those first commercially available foam wings were not cored out internally, and they were sheeted with very heavy contact type glues. Internal coring, when it came along in the late 1960s, helped a bunch to eliminate unnecessary weight, but there was (and still is...) an inherent build up of excess weight near the tips. That most famous of all CL Stunt articles - written by Bob Gialdini - on the Olympic MK VI highlighted the "barbell" effect and the desirability of light extremities.

The foam wing did eventually earn its "wings" (pun most certainly intended...) in the 1970s, as many who wanted to fly competitive CL Stunt did not possess the skills to build a strong and accurate built-up wing. As virtually everyone here knows, Mike and Arnnie Stott of "Foam Flite" fame and your's truly at Control-line Specialties Co. (later known as Control Specialties Corp.) produced hundreds - if not thousands - of foam cores and sheeted foam wings during that decade. Bob Lampione broke through in 1969 for the first Nats win with a foam-winged model, and some years later in 1976 that crazy hippie kid from New Jersey won a Nats flying a rudderless foam-winged model. (Some would say that then, and even today, that "kid" is still rudderless...). As a data point, Gene Schaffer placed second at that Nats, also with a foam-winged model. At that point I'd venture to say that the majority of the models flown at the Nats had foam wings in them. But, the foam-winged ships did not dominate in terms of wins; the built-up wing in the hands of expert builder/fliers was still the thing to beat.

In the 1980s Jimmy Casale and Paul Walker had many amazing duels at the Nats. Jimmy flew mostly foam-winged models (although he did have a few notable built-up wing ships in that era), and Paul - if I'm not mistaken - also had a few of each. And, Ted Fancher had a few wins with foam-winged models in that decade. The line between the performance of the foam-winged models and the ones with built-up wings was starting to blur. My win at the 1978 World Championships marked the first win at such an event by a foam-winged model, and it would be many years before another one would score the Gold at a WC event. Igor Burger has done it twice in recent years, and Richie Kornmeier has also scored a "popcorn" wing win. (My very good friend, CL Stunt mentor, and Best Man at my wedding, Bill Simons coined the "Popcorn Wing" phrase, and it stuck - at least it did on the East Coast for many years...) 

As far as foam-wing kits are concerned, I'm pretty sure that Randy Smith still offers his fine SV line of designs with foam wings. The real problem with a foam wing kit is the size of the box required to ship the wing, and the attendant cost to ship it. The brutal truth is that many CL fliers are not prepared to spend the required bucks to get what they want. This is about the least expensive motor-sport on the planet, and to be successful one must be ready to pay the going rate for top-of-the-line equipment, That means the plane, the powerplant and the finishing materials.

Most also don't know just how much time and effort is required to produce a quality sheeted foam wing. The foam certainly doesn't cost much, but the contest grade balsa can be very expensive. The main reason that foam wings cost what they do is the hours of painstaking work that is required to make a wing that is as light, strong, and accurate as possible. Many times when I quote a price for a sheeted foam wing over the phone, I hear a deafening silence for a few moments. Then a common response is something like, "That's a lot! Hey, it's only a hobby!" It may be a hobby to them, but to me - and to the others who produce these wings - it is part of, if not entirely, our livelihood. Why shouldn't we get just as much per hour of highly skilled work as anyone else? Of course, there are those who fully understand economics and want what they want, and they never complain about the price.

Having written all the above in defense of foam wings, let me close by commenting that a properly built, accurate and strong built-up wing is just as desirable as a foam wing. Different strokes for different folks.

Later - Bob Hunt           
« Last Edit: August 14, 2017, 10:51:28 AM by Bob Hunt »

Offline Peter Nevai

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Re: Contact Spray Adhesive, a simple question.
« Reply #34 on: August 13, 2017, 11:42:45 AM »
Of course A finished foam wing is expensive. But all the kits I had built with foam wings, (Sig Magnum, Midwest Mustang Stunter, Custom Hobbies ForeRunner) and a few others the wing cores were not finished. Not sheeted, not the leading edges or trailing edges installed. They were the foam cores only. The builder had to do the work. Which was OK by me. You would have to install the spars, gear mounts, sheeting, tips etc. I would be very fine with that. The Sig Magnum even had a foam Stab, again only the foam cores you had to finish them yourself. Saved a whole ton of time and no night sweats about warps. I suppose I could buy a wood kit and not use the wing parts and order a foam wing for it, but that is just a waste of wood, money and time.

Of course you could not do a foam kit in a box 4" X 4" X 48" But I do not recall the boxes the being that huge. But of course that was back in the day when large manufacturers were producing the kits and CL was still somewhat popular.
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Re: Contact Spray Adhesive, a simple question.
« Reply #35 on: August 13, 2017, 12:27:36 PM »
Bob
 
To slightly further hijack the adhesive thread

Do, or will you, quote a price for a custom set of ( 2 or more) sheeted foam wings?

I am not longer capable of building a kit wing with balsa / ply that is up to my own, warp free, standards and willing to pay for good wing sets for several profile planes I want to play with

specifically Twister, Primary Force, Ring master, or SkyRay

Cost to me is not a concern...working trouble free wing is

I know I should have PMed or e-mail you but though you answer may be relevant to many more than just me
"A good scare teaches more than good advice"

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"The unpunished never learn"

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Offline Bob Hunt

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Re: Contact Spray Adhesive, a simple question.
« Reply #36 on: August 13, 2017, 12:42:12 PM »
Hi Fred:

Thanks for your interest. To keep this as non-commercial as possible, please give me a call at 610-746-0106 and we can discuss your needs and pricing. Please don't call today; I'm just getting ready to leave to play at an open mic gathering (Sunday afternoon). I'll be back late, so if you call, please make it tomorrow or any week day.

Thanks - Bob

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Re: Contact Spray Adhesive, a simple question.
« Reply #37 on: August 13, 2017, 01:06:47 PM »
wilco

Have fun,
i know that is one of your dedicated passions
"A good scare teaches more than good advice"

"Worry is the interest you pay when you borrow trouble"

"The unpunished never learn"

Fred von Gortler IV


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