Author Topic: What glue to use (Read 3097 times)

Geoff Goodworth · « **on:** March 25, 2019, 10:59:19 PM »

I rekitted a Skyray 35 several months ago and it now time to start bringing it back to life.

The model was built with CA and all the half ribs popped out undamaged due to failure at the glue joints.

What adhesive should I use to reassemble it?

Dave Hull · « **Reply #1 on:** March 25, 2019, 11:22:05 PM »

I'd use Titebond. It won't soak into any of the CyA'd areas, but it should still hold better than anything else but epoxy. No need to go all the way to epoxy. I am a fan of squeezing the glue out into a puddle, and then dabbing what you need out with a small paintbrush. Brush the joint and assemble. There should be enough applied to create a fillet on both sides of the rib. The Titebond will not be as shock-sensitive as CyA.

Good luck with your Phoenix Skyray.

Dave

Peter in Fairfax, VA · « **Reply #2 on:** March 26, 2019, 09:58:44 AM »

Slow drying epoxy would work.

FLOYD CARTER · « **Reply #3 on:** March 26, 2019, 10:54:14 AM »

Glue for general purpose balsa work is just a matter of personal preference. Us epoxy for motor mounts and plywood. But balsa glue can be Titebond, CA, or SIG-ment. I typically use CA to tack things together, then go over the joints with SIG glue.

BillP · « **Reply #4 on:** March 26, 2019, 08:13:17 PM »

It isn't normal for CA to let parts pop loose. Thin CA pulls balsa grain instead of a glue line failure same as epoxy so I think you had either loose fitting joints or a bad batch of CA. I do what Floyd Carter does, CA (liberal) to tack it quickly and Sigment types over the joints. I've always used Duco, Ambroid or Sigment on doublers and motor mounts and never had delamination or a glue failure...that goes for CL and 60 size RC ships that were flown hard or crashed hard.

Curare · « **Reply #5 on:** March 26, 2019, 09:45:17 PM »

What you will find that is if the CA is too thin it won't bridge wide gaps, and it'll soak into the surrounding wood, stiffening it - so you have strong materials held together by a whiff of CA.

If you try to repair it with an aliphatic or PVA it won't adhere well to the CA'd wood, and you'll have another weak joint.

Best get some Thick CA and try again, and buy good stuff. No Aldi CA!

Scott Richlen · « **Reply #6 on:** March 27, 2019, 06:29:02 AM »

On your next new build use a wood glue (I use the white glue made by Gorilla, just don't get the polyurethane of that brand by mistake), water it down 10 to 15% so it penetrates better, and use an applicator bottle with coarse needle to apply it using Tom Morris' "dot method". You want to build your planes to fly, not to crash. Never make "glue fillets", make tight joints instead.

Some people become sensitized to CA's. You won't know if you are until you do, so I only use CA for applications where nothing else will work.

Generally, if you use CA on a joint, wood glue doesn't work well for repair and vice versa.

John Lindberg · « **Reply #7 on:** March 27, 2019, 07:17:46 AM »

There was a review of glues in the "Flying Aces" publication a few years ago, the best glue, according to the author, is Titebond II.

Scott Richlen · « **Reply #8 on:** March 27, 2019, 07:36:26 AM »

Quote

There was a review of glues in the "Flying Aces" publication a few years ago, the best glue, according to the author, is Titebond II.

......using glue dots.......

Andre Ming · « **Reply #9 on:** March 27, 2019, 08:32:50 AM »

Good ol' Ambroid in the tube.

Oh wait... we can't get that anymore.

Nevermind.

Andre

Dave_Trible · « **Reply #10 on:** March 27, 2019, 10:18:39 AM »

I just built my new 2019 fleet using the Titebond/Morris dot method. It sure builds lighter. My only disappointment was to find that while the glue itself is very strong, it doesn't soak in and adhere to the balsa very well. It doesn't take much to pop joints loose and where I was afraid vibration might shake loose some important bonds I used something else. It is adequate for most of the structure where there is overall strength in many joints but Sigment and the like soak in better and make a better joint though the finished weight will be a little more. Best yet might be 'dot gluing' with the Sigment. An issue with that would be it soaking in and drying before you can get larger assemblies together like wing sheeting or attaching a molded fuselage shell. Cya glues are fast and there is always a bottle on my table but can actually build heavier if overdone since they loose no weight when they set-like epoxy.

Dave

Ken Culbertson · « **Reply #11 on:** March 27, 2019, 11:16:41 AM »

When I came back to building a couple of years ago I was shocked that I couldn't get Ambroid anymore so I switched to using CA in various thicknesses. I had used Tightbond back in the day where lamination was required but I never liked it. Could never get a seam to disappear with sanding and it warps if you don't watch it till it is 100% dry. I find the JB Weld CA that you can get everywhere to be a fantastic way to build. You can spread it out on laminations just like epoxy and it sands 10 times better and sooner than epoxy. I always hated the "glue and wait till it dries" from the old days. CA lets you simply build. I also like the way you can press fit pieces together and let the CA flow through the joint and leave no seam.

I know it is heresy, but I don't double glue like a lot of folks and my planes don't fall apart. I just test all of the joints and fix any lose ones. If however I do double glue (like around the bellcrank or landing gear) I use JB then wipe the excess (like you are making a fillet). Once it is shrink wrapped with whatever covering you like, those joints aren't going anywhere and you are just adding weight. Balance your props and the joints aren't coming loose.

The only downside to CA (other that the wife screaming about the smell

) is that the tip of the bottle will clog occasionally, no, make that often, and it will most often squirt out and get all over your fingers when you clear it. Then you ALWAYS make the mistake of trying to pull them apart with your other hand.

That is why you should have a bottle of de-bonder open and learn to apply it with your teeth.

Oh, and one more thing. Never let CA get uphill from a hinge or horn bushing. They have tiny homing devices and if you get too close you are going to have to answer the question: "Daddy, what does that word mean?"

Ken

BillP · « **Reply #12 on:** March 27, 2019, 11:56:25 AM »

Quote from: Andre Ming link=topic=53059.msg549995#mslug549995 date=1553697170

Good ol' Ambroid in the tube.

Oh wait... we can't get that anymore.

Nevermind.

Andre

...but Duco is still available. I like it better than Sig-Ment.

Scott Richlen · « **Reply #13 on:** March 27, 2019, 03:41:35 PM »

Quote

it doesn't soak in and adhere to the balsa very well

Dave: did you dilute with 15% water? That really seems to help the glue soak in.

The reason I use the Gorilla white glue is that it sands better than the others. The very best of all (for sanding) was PICA GluIt, but that's been gone for years. But the Gorilla white comes awful close.

Dave_Trible · « **Reply #14 on:** March 27, 2019, 05:11:00 PM »

Quote from: Scott Richlen on March 27, 2019, 03:41:35 PM

Dave: did you dilute with 15% water? That really seems to help the glue soak in.

The reason I use the Gorilla white glue is that it sands better than the others. The very best of all (for sanding) was PICA GluIt, but that's been gone for years. But the Gorilla white comes awful close.

Hi Scott. No I did not dilute the glue. That likely would help. In any event I am thinking (hoping) these machines will stay together. Most the structure is encased in a carbon shell so I may never know how well the joints hold up. I did really like the long working time.

Dave

Dave_Trible · « **Reply #15 on:** March 27, 2019, 05:15:01 PM »

Ken Culbertson · « **Reply #16 on:** March 27, 2019, 05:43:53 PM »

Quote from: Dave_Trible on March 27, 2019, 05:15:01 PM

...

Nice - That is a big puppy! What is it going to be when it grows up? Sort of looks like a Hellcat or Wildcat.

Ken

Dave_Trible · « **Reply #17 on:** March 27, 2019, 06:08:56 PM »

Ken it's not semi scale. It's the latest cousin of Desperado. The series I'll call Silhouette from an old design of mine long ago. There are now three-I destroyed the mold buck after three sets of shells. This was the first one-Special Request.

Dave

Ken Culbertson · « **Reply #18 on:** March 27, 2019, 06:16:22 PM »

Quote from: Dave_Trible on March 27, 2019, 06:08:56 PM

Ken it's not semi scale. It's the latest cousin of Desperado. The series I'll call Silhouette from an old design of mine long ago. There are now three-I destroyed the mold buck after three sets of shells. This was the first one-Special Request.

Dave

It sure looks good. I am also building one I designed back in the 60's for classic. It is fun seeing it again!

Ken

Dave_Trible · « **Reply #19 on:** March 27, 2019, 06:26:08 PM »

Thank you. These have been a lot more work than anything I've done but I don't think I'm going back. The last one is in finishing stages and is a take-apart.

Dave

Scott Richlen · « **Reply #20 on:** March 27, 2019, 06:58:28 PM »

That's a good-looking ship!

Dave_Trible · « **Reply #21 on:** March 27, 2019, 07:17:06 PM »

Quote from: Scott Richlen on March 27, 2019, 06:58:28 PM

That's a good-looking ship!

Thx!

John Lindberg · « **Reply #22 on:** March 28, 2019, 06:02:36 AM »

In the review of glues in the "Flying Aces" article, there was no mention of "glue dots!"

Dave_Trible · « **Reply #23 on:** March 28, 2019, 06:23:39 AM »

The glue dots came from Tom Morris. If done well, it may be the lightest way to build since the glue contributes very little to the weight. You've created a metering method for it. He uses almost exclusively white glue for building but the glue can get heavy. He rigs a bottle with a small spout and lays down a series of glue dots perhaps 1/4" to 3/8" apart down a line he wants to glue. When the parts are joined the glue spreads a little on it's own and leaves just about the right amount without any extra . I've built three large airplanes now from one bottle of Titebond and still have 1/3rd left. I rigged up a small squeeze bottle with a piece of 5/32" aluminum tubing for a spout. You have a very long time to work on getting something glued and put together straight. Then it has to set overnight before you move on. As somebody mentioned it's better to keep it away from surfaces that will later be exposed to finish. There is where I used the Sigment. I may well try to thin the glue next time as Scott suggests.

Dave

Scott Richlen · « **Reply #24 on:** March 28, 2019, 06:56:38 AM »

Quote

In the review of glues in the "Flying Aces" article, there was no mention of "glue dots!"

Well John, that's because they are just not as advanced as us control liners. We is, like, "totally modern Millie" and stuff like that. Someday the rest of the hobby will catch up with us and use glue dots. Then they too will be, like, "totally modern Millie"! Don't cha see? Like, no one is going to take you seriously in stunt-ville unless you use glue dots. I'm thinking we should institute an award at Brodaks for "Best Glue Dots". That could trigger a full-blown stunt-lemming run!

FLOYD CARTER · « **Reply #25 on:** March 28, 2019, 11:53:52 AM »

Oh yes. And never try to clear a clogged CA bottle tip with your teeth. Doesn't end well.

Discouraging to find that if you already have cured CA on a joint, a second try with CA will not work. I've had to scrape/sand cured CA off the parts before a second application would work.

Ken Culbertson · « **Reply #26 on:** March 28, 2019, 02:15:18 PM »

Quote from: FLOYD CARTER on March 28, 2019, 11:53:52 AM

Oh yes. And never try to clear a clogged CA bottle tip with your teeth. Doesn't end well.

Discouraging to find that if you already have cured CA on a joint, a second try with CA will not work. I've had to scrape/sand cured CA off the parts before a second application would work.

I use JB if the joint already has CA. It seems to bond to the CA already there. Regular CA may not even cure on a second try with out "kicker" and just sit there waiting to grab a passing finger or just strike out on it's own in search of a flap hinge to ruin.

Ken

Dave Harmon · « **Reply #27 on:** March 29, 2019, 09:03:38 AM »

Quote from: Scott Richlen on March 27, 2019, 03:41:35 PM

Dave: did you dilute with 15% water? That really seems to help the glue soak in.

The reason I use the Gorilla white glue is that it sands better than the others. The very best of all (for sanding) was PICA GluIt, but that's been gone for years. But the Gorilla white comes awful close.

I never liked Titebond ll so I tried Elmer's Carpenter glue....no water needed.
It looks like TB2 but it dries faster and best of all....it sands nicely...cheep too!
Usually I get the Carpenter glue in the usual TB2 looking bottle but it is available in gallons as well.
For applicators....I use Veterinary plastic syringes that have a short stub point.
Clean em' out with water and reuse....buy them by the bag.