Author Topic: SLC OVER Polyspan? (Read 46577 times)

Doug Burright · « **Reply #50 on:** February 18, 2015, 11:06:12 PM »

Larry,

So, just what the heck IS SLC, and where do we get it?
I know the process for silkspan and dope, etc., but what is the SLC?
I would be more than happy to put a lighter, stronger finish on the airplane, but have no idea what the SLC is.
Please explain.
Thanks,
Doug.

Larry Renger · « **Reply #51 on:** February 21, 2015, 11:54:01 AM »

SLC is a thin film with adhesive backing. It is applied with an iron ant then heat shrunk. I bond it over undoped Polyspan.

It is available from Corehouse Models.

phil c · « **Reply #52 on:** March 29, 2015, 07:22:23 PM »

A little background on SLC covering. As Lauri guessed, it is polyester with a fuel proof, heat seal adhesive on it. It's less than .001 thick, so if the edges are properly ironed down they will disappear. You can barely see the line and most people can't feel an edge less than .001 or .002in. thick. The film edge will get buried under primer and paint. I'd be more concerned about the polyspan edges showing through. The film is about 1oz/sq.yd.

Doug Moon used it on his Gieseke Nobler ARF's a few years ago. He and others put automotive paint and clear directly on the film with good success.

After six or seven years of leaving planes in the car for a week some of them have developed bubbles on flat balsa sheet sides. They can be ironed back down without hurting the paint.

The website, sadly out of date, has info or send me an email. home.earthlink.net/~philcartier
A 10-12ft sample is $6, prepaid. 100ft x 15.5in. roll is $35 plus $6 or USPS Priority mail and $1.25 for PayPal if you don't want to prepay by check or MO

I can't take credit cards at the moment. Visa screwed me out of a goodly sum on a processing error, so I'm looking for alternatives.

dennis lipsett · « **Reply #53 on:** March 29, 2015, 11:45:01 PM »

Quote from: Larry Renger on August 14, 2013, 10:44:37 PM

So, what brave soul will be the first to try this? It REALLY works.

Larry this is not a new process. I have covered like that on several occasions for years and yes the film will stick tenaciously to either silkspan or Polyspan. You also get a side benefit in that you can put the film on in pieces to achieve a complex color scheme by doing this method. picture of my walt Umland Edge 540 will show you that it is a completely viable solution. Each piece of the wing/tail design was cut separately and applied. Your also right in that the method gives incredible torsional rigidity to the wing

Larry Renger · « **Reply #54 on:** March 30, 2015, 08:21:04 AM »

Wow! Very spectacular decor. Thanks for showing it.

Steve Thornton · « **Reply #55 on:** April 24, 2015, 05:22:43 PM »

Thanks for the great thread Larry. I'm ready to cover my Baby Flite Streak, and need a bullet proof plane to learn to fly inverted, so I am covering with your method and have 2 questions:
1. At what stage should I apply Super-Fil for the fillets...before or after I cover the wing?
2. What size tank should I use for my Norvel Big Mig 061?
I always learn a lot from you guys!
Steve Thornton

Larry Renger · « **Reply #56 on:** April 27, 2015, 09:01:42 AM »

I would do the fillets after the Polyspan but before the SLC.

A 1 ounce tank should do.

Steve Thornton · « **Reply #57 on:** May 09, 2015, 02:52:56 PM »

Larry just one more question, what method did you use to apply the Polyspan? Did you use dope or Balsarite or stix-it? Thanks again for this post it's a great idea.
Steve

john e. holliday · « **Reply #58 on:** May 10, 2015, 05:12:10 PM »

Go read reply number 6.

Yes, I'm mean and nasty in my old age.

Steve Thornton · « **Reply #59 on:** May 11, 2015, 01:57:33 AM »

Reply #6 "The only dope used is enough to bond the Polyspan to the wing structure. No dope on the open bays at all!" Does this mean that the polyspan is not bonded to the ribs? Sorry if you are getting impatient with these questions, but I don't want to make a mess of a plane I have worked on to be straight and strong. Doc, I'm not stupid but I'll admit to being ignorant!
Steve

john e. holliday · « **Reply #60 on:** May 11, 2015, 11:39:22 AM »

I think you don't want the poly-span doped to the ribs. Might be faster if you send Larry a PM. He is a nice gentleman.

Larry Renger · « **Reply #61 on:** May 13, 2015, 09:27:44 AM »

I do dope theribs tomake them smooth, but don't bond the polyspan to them. Some bonding does happen in the heat shrink and SLC overlay process. You want the polyspan to have as much leeway to shrink evenly as possible.

So faras I have experienced, any film covering will work, but you will find major weight and paint adhesion differences.

Hard as it may be to believe, I don't have ALL the answers!

Steve Thornton · « **Reply #62 on:** May 13, 2015, 11:11:57 PM »

Thanks for the work & info Larry. You have given me a plan & a track to run on. While you may not have all the answers, you do have a very innovative idea and that's way ahead of me. I am curious if some Balsarite on the ribs might allow the span to adhere after shrinking & prevent the covering from "floating" while in flight. It wouldn't add much weight & would add some torsional strength. I'll give you a report after vacation.
Steve

Larry Renger · « **Reply #63 on:** May 28, 2015, 09:13:12 AM »

Balsarite should work too.

Larry Renger · « **Reply #64 on:** June 25, 2015, 11:53:54 PM »

Any input from people who have tried this? Enquiring minds want to know, especially if there are issues to be overcome! It works great for me, but I don't do 20 point models.

Larry Renger · « **Reply #65 on:** August 23, 2015, 08:12:05 PM »

7000+ viewings, and nobody trying it? Astounding!!! Give it a shot on a junker refit and maybe you will come to love it. How hard is this?

Ara Dedekian · « **Reply #66 on:** August 24, 2015, 07:45:26 AM »

Quote from: phil c on March 29, 2015, 07:22:23 PM

A little background on SLC covering. As Lauri guessed, it is polyester with a fuel proof, heat seal adhesive on it. It's less than .001 thick, so if the edges are properly ironed down they will disappear. You can barely see the line and most people can't feel an edge less than .001 or .002in. thick. The film edge will get buried under primer and paint. I'd be more concerned about the polyspan edges showing through. The film is about 1oz/sq.yd.

Doug Moon used it on his Gieseke Nobler ARF's a few years ago. He and others put automotive paint and clear directly on the film with good success.

After six or seven years of leaving planes in the car for a week some of them have developed bubbles on flat balsa sheet sides. They can be ironed back down without hurting the paint.

Phil

Here's what happened to my SLC () covered Clown racer built in 2001. The covering is what Steve Sacco used on his combat ships back in the '80's and measures .0015". The paint is System Three Inc.'s line of water based urethane marine paints which was sold by Nelson Aircraft Co. (RC stuff). The Clown spent years in attics subject to extremes of temperatures and over the last couple of years shed its paint. The covering was scuffed with OOO steel wool prior to painting.

Is the covering a thicker version of SLC? Was the water based paint the problem? I have enough of the material left for one or two more planes and it's so light I'd be tempted to try it again as per Larry's suggestion.

Ara

Rick Huff · « **Reply #67 on:** August 26, 2015, 05:20:03 AM »

My Chipmunk is still looking good after about 1 year. No problems so far.
Rick

Motorman · « **Reply #68 on:** December 20, 2015, 08:55:54 PM »

One thing I don't understand. Do you shrink the polyspan before you apply the SLC or do you shrink them together as you're applying the SLC? How does all that work?

Thanks,
MM

Rick Huff · « **Reply #69 on:** December 21, 2015, 05:06:35 AM »

I've done 6 planes with either SLC or Ultracote over polyspan and I've shrunk the polyspan first. I'm not sure it makes too much difference, though.
Rick

jfv · « **Reply #70 on:** December 21, 2015, 08:49:18 AM »

I tried it out on one of my nostalgia combat designs from the early 60's that I put together for this fall's GSCB meet. I wanted the doped tissue look but didn't have the time. Worked out pretty well. A number of people asked me what I cleared it with.

Larry Renger · « **Reply #71 on:** December 21, 2015, 09:02:10 AM »

I definitely shrink the polyspan first.

That combat job looks great! Imagine what it would weigh and the time and money spent if you tried to get that gloss with dope!

Motorman · « **Reply #72 on:** December 22, 2015, 12:51:59 PM »

Have you tried painting the adhesive side of the SLC?

MM

Larry Renger · « **Reply #73 on:** December 22, 2015, 06:33:01 PM »

I haven't done it, but the free-flight guys do regularly.

Walter Hicks · « **Reply #74 on:** December 22, 2015, 08:02:08 PM »

Larry I am getting ready to cover a Little Jumping Bean wing. I have some Polyspan lite, has anyone tried your method with this?

Larry Renger · « **Reply #75 on:** December 23, 2015, 08:26:13 AM »

Quote from: Walter Hicks on December 22, 2015, 08:02:08 PM

Larry I am getting ready to cover a Little Jumping Bean wing. I have some Polyspan lite, has anyone tried your method with this?

Yes, I have, and it is a great use for the light stuff. Coupled with one of the "park flyer" coverings you get a really light weight, fancy finish.

Here is a sample! The model is the Sky Sport, kitted by RSM and designed for .061 power, though a Tee Dee .049 would do the job on shorter lines.

Motorman · « **Reply #76 on:** January 26, 2016, 09:00:23 PM »

Is that Coverite Microlite Transparent Yellow? Website says .6oz sq. yd. and already has color.

MM

Larry Renger · « **Reply #77 on:** January 28, 2016, 08:11:40 AM »

Yup, Microlite it is.

Motorman · « **Reply #78 on:** January 28, 2016, 07:24:48 PM »

Outstanding, I'm going with Microlite over polyspan lite on my next 575 sq in wing. If you google polyspan lite Larry Davidson's name will come up, great guy to deal with. Tower has the gloss white microlite cheaper than the Coverite site but no other colors. Where do you get your Microlite?

MM

Larry Renger · « **Reply #79 on:** January 28, 2016, 07:32:37 PM »

I just got transparent red and yellow from Tower. I don't think they like you

Also transparent blue from Smith Brothers in Reseda, CA. I DON't know if they do web sales.

Motorman · « **Reply #80 on:** February 07, 2016, 10:39:03 PM »

ha ha very funny. I see they just got a bunch of colors in with more on the way, good for us. You must have timed it just right, showing out of stock already on trans red & yellow.

MM

Larry Renger · « **Reply #81 on:** February 09, 2016, 12:47:40 PM »

I am just finishing an RSM Ringmaster. The covering is lightweight Polyspan with white Microlite film covering bonded over it. So far, so good!

The polyspan was ironed down with Mod Podge. I did find the glue soaks through the covering and needs to be cleaned off the iron occasionally. Acetone does the job.

First photo is the polyspan. You can see that it is way lighter than the regular stuff. Second photo is the finished wing. There is a faint texture to the surface, but it sure is shiny!

Wow! Eleven Thousand hits on this thread, and counting! The only one I found with more is Bob Hunt's electric twin development thread with Forty-nine thousand hits (something to shoot for, guys!) Y

john e. holliday · « **Reply #82 on:** February 10, 2016, 10:33:56 AM »

That is sure shiny. I got some Mod Podge to use.

Mike Griffin · « **Reply #83 on:** February 12, 2016, 10:45:43 AM »

Larry is definitely n to something here. I did a test panel a couple of days ago using this method and it appears to be almost bulletproof and very light.

Mike

Motorman · « **Reply #84 on:** February 12, 2016, 11:56:24 AM »

Got some Mod Podge. Looks and smells like a thick pasty polycrylic. I'm doing some adhesion testing. Ironing polyspan over Mod Podge doesn't take as much heat as monokote. I was also able to iron on polyspan over polycrylic painted on bare wood. The third test is polyspan put on by brushing through with polycrylic although it is the heaviest/strongest it came out lumpy. I'll let you know what happens when I try to pull them up.

Also if you're doing the edge and you want to wrap it around you have to apply more Mod Podge to the edge because it won't go through 2 layers of polyspan.

Thanks,
MM

Motorman · « **Reply #85 on:** February 13, 2016, 06:02:04 PM »

Adhesion tests are done. A 2" strip was tacked down on balsa and left to hang over the edge for something to pull on.

Mod Podge brushed on wood then polyspan ironed on - Pulled off very easy without ripping the cloth

Polycrylic brushed on wood then polyspan ironed on - zero adhesion

Polycrylic brushed through polyspan - Cloth ripped in half, got some of it to pull off at the edge but balsa came with it, had to be removed with 60 grit sandpaper and it was solid all the way down.

In my opinion Mod Podge is an arts & craft glue that's not good enough for model use.

MM

john e. holliday · « **Reply #86 on:** February 14, 2016, 04:46:05 PM »

You forgot there was SLC over the poly-span.

Motorman · « **Reply #87 on:** February 14, 2016, 05:36:30 PM »

I don't follow. The glue on the film will hold it to the polyspan but the mod podge is the weak link under it all. If you seal the edges with some epoxy or something it might not give you any trouble.

I like the way polycrylic worked but I think it's heavy. I'm going back to good old Sig nitrate.

MM

Larry Renger · « **Reply #88 on:** February 14, 2016, 07:16:36 PM »

I agree that Mod Podge adhesion seems a bit weak, but it has proven adequate for me so far. My real complaint is that it soaks through the lightweight Polyspan and sticks to the iron, making it draggy on the tissue.

I have a can of water based contact cement I want to experiment with. Anyone tried that stuff?

Larry Renger · « **Reply #89 on:** February 20, 2016, 09:37:15 PM »

See the finished model in the main forum.

john e. holliday · « **Reply #90 on:** February 21, 2016, 02:28:31 PM »

Quote from: Larry Renger on February 14, 2016, 07:16:36 PM

I agree that Mod Podge adhesion seems a bit weak, but it has proven adequate for me so far. My real complaint is that it soaks through the lightweight Polyspan and sticks to the iron, making it draggy on the tissue.

I have a can of water based contact cement I want to experiment with. Anyone tried that stuff?

Yes, it is just as bad. Have to clean the iron every so often.

Larry Renger · « **Reply #91 on:** March 18, 2016, 09:44:32 PM »

Lucky me, I flamed out in the four leaf clover and slid in inveted on asphalt. Lots of rework needed on the canop and rudder, but only a barely discernable scuff on the covering! YAY!

Larry Renger · « **Reply #92 on:** July 02, 2016, 06:40:57 PM »

My Ringmaster has been to hot flying fields for several months now, and the covering is still taut! Nary a wrinkle.

. Looks good as new too. Plus the water slide inkjet decals are still perfect.

You got to try this!

john e. holliday · « **Reply #93 on:** July 06, 2016, 10:10:46 AM »

Larry, my next plane is going to get this treatment. Thanks.

Larry Renger · « **Reply #94 on:** July 06, 2016, 07:06:19 PM »

About time!

Motorman · « **Reply #95 on:** July 17, 2016, 10:16:56 PM »

Well it works, couldn't believe how light and strong this came out. I want to strip the monokote off my other airplanes.

3 coats of Nitrate thinned 50/50 (could have used 2) then polyspan lite put on with 10% nitrate 90% thinner. Shrink with heat gun then applied Coverite Microlite white.

Everything went pretty normal, no weird problems and it stays tight in the hot July sun. I did the wing and tail surfaces, the fuselage is just Sig butyrate white on bare wood sparingly.

MM

Larry Renger · « **Reply #96 on:** July 20, 2016, 04:23:45 PM »

Looks great! Is that a Pathfinder?

Motorman · « **Reply #97 on:** July 22, 2016, 10:35:22 AM »

It's mostly a TunderGazer.

Fredvon4 · « **Reply #98 on:** July 22, 2016, 11:21:44 AM »

Getting ready to put 8mm blue silk on a Pat Johnston S-1 (ish) Ring Master wing for a plane I hope to keep under 26 oz

Does anyone think the SLC ( I have plenty of) is a good idea on top to keep from dope, dope, dope weight adding?

And if so-- should I put ANY dope ( perhaps one cote of tautening) on the silk panels first?

Remember the RM is a polywog rib set

Larry Renger · « **Reply #99 on:** July 24, 2016, 08:00:24 AM »

one very thin coat of taughtining dope might be good. You do NOT want to fill the weave or you will get bubbles of un-attached film. Definitely be sure the silk is well adhered to the ribs.

Let us know how it comes out, and show photos!