Glues for motor mount installation

[Micromeister]

We were talking earlier in this thread about the glue deforming body tubes around the motor mount rings.
Thought I'd share a photo showing this glue Draw with another adhesive in another of the area this damage can occur.
I'm working on a replacement sustainer for my Old Estes Delta Star 2-star payload model. using as many of the original parts as I could slavage. In this pic it clearly shows the Tube Draw in the payload section where I used a very heavy fillet of ambroid to help fill in some of the irregular surfaces of a re-used balsa nose block.
Instead Of leaving the Nose cone off the payload section while the glue dried I stupidly popped it in place before I closed up the workshop for the night. You can see the results in this close-up, which will now need to be filled and sanded smooth.
In this case this draw could have been completely prevented by simply leaving the nose off. With Motor mounts a couple small holes in the rear centering ring is usually enough to prevent this type of suction draw
Hopefully this helps illistrate it isn't the glue type but the suction created as the glue or adhesives use the oxygen inside the sealed portion of the tube during drying
Hope this helps.

 

[vicious-peanut]

Originally posted by BobCox
How well have they been holding together for you? I was always told that CA should not be used near elastic because it attacks the rubber, in addition to being brittle.

Actually, not very well.

I had it rip in half (still held, but wouldnt have for another launch) on my Baby Bertha with the 24mm mount. I replaced it with Kevlar.

 

[Zack Lau]

Attaching centering rings with yellow glue deforms body tubes more than white glue. I find this to be a problem with installing paper wraps, such as the body wrap on the 4" Estes R2D2. These were installed 4 to 5 years ago, and stored next to each other for the last few years.

 

[flyingeagle]

Im just as confused now! Is Tite Bond lll the way to go when installing engine mounts or white Glue All? I’m only building LPR to MPR. I have the go to glue for the fins. I’m just interested on what glue is the strongest glue for motor mounts without that quick grab. Not using epoxy for this. White Glue All to mount centering rings to body tube or Tite Bond lll with more time to adjust unlike Tite Bond ll with with quick grab???????

 

[neil_w]

White glue definitely works well. I haven’t used TBIII so can’t comment on its grabbiness.

I do often use epoxy for this; you only need to mix up a very small amount and it makes the mount slide in really easily. Just need to keep it horizontal while it cures so the mount doesn’t drift out of position.

 

[Antares JS]

Im just as confused now! Is Tite Bond lll the way to go when installing engine mounts or white Glue All? I’m only building LPR to MPR. I have the go to glue for the fins. I’m just interested on what glue is the strongest glue for motor mounts without that quick grab. Not using epoxy for this. White Glue All to mount centering rings to body tube or Tite Bond lll with more time to adjust unlike Tite Bond ll with with quick grab???????

You're massively overthinking this. White glue is fine for all stages of LPR paper-to-paper or paper-to-wood construction. I have been using Aleene's Tacky Glue for 26 years for my LPR's and have never had a single glue joint fail or something get stuck out of place. Your technique matters far more than what glue you use. Test fit the motor mount before applying any glue to make sure it slides in smoothly, and you will be fine.

 

[flyingeagle]

Epoxy sounds good to but if you mix to much than needed then I wind up throwing away money but often thought about it. How well dose it hold up compared to wood glue with heat?

 

[neil_w]

Epoxy sounds good to but if you mix to much than needed then I wind up throwing away money but often thought about it. How well dose it hold up compared to wood glue with heat?

For LPR and MPR any of them are fine. Really white glue is the least heat-resistant of the bunch, but I don't think it's likely ever to be a problem with these motor classes.

It's the mounts with thick paper centering rings that usually send me to the epoxy. For plywood, fiber, or cardstock rings I'd be less worried about the grabbing.

 

[flyingeagle]

I have regular Elmers wood glue but not sure if it will grab as fast as the Tite Bond ll glue. I might need just that short amount of time to adjust something before it grabs. Tite Bond ll can get you into trouble.

 

[neil_w]

Regular wood glue should be close to Titebond Original. You can see it's only slightly better in that regard than TBII. You can always do some experimentation if you really want to understand the behavior of each type of glue (I am making an assumption that "Assembly Time" should be roughly proportional to "grabbiness".)

 

[flyingeagle]

I’m working on the Estes QCC Explorer and taking my time and it’s coming out grate. I’m using model plastic tube on the engine mount for a kevlar mount and epoxy to glue it to the motor mount but I want a strong mount to the body tube.

 

[neil_w]

Any of these white glues, wood glues, or epoxy should be fine for strength.

 

[flyingeagle]

I looked for hollow plastic coffee straws for running Kevlar cords through but the holes are to big. I found plastic tubbing in the model dept at Hobby Lobby instead.

 

[flyingeagle]

Someone posted earlier that Tite Bond lll has les grab tome than the ll but never used it.

 

[flyingeagle]

What kind of glue is best for gluing plastic to a body tube

 

[flyingeagle]

The best glue I have ever used in the 80s and 90s was Wellbond white wood glue. I have never seen it since then

 

[flyingeagle]

Correction it was Weldbond

 

[flyingeagle]

Some of my rockets I will be flying on F and G motors the rest A through E

 

[mh9162013]

What kind of glue is best for gluing plastic to a body tube

Fabritac

 

[flyingeagle]

Not familiar with that. It sounds like it’s for joining fabric together? How strong is it?

 

[flyingeagle]

I have a plastic motor nozzle that has to be glued to the body tube

 

[samb]

I think we all suffer from an embarrassment of glue riches. One thing that you want to watch out for when using wood/white glue for couplers and motor mounts is shrinkage dimpling the thin LPR body tube. You'll sometimes end up with a ring around the airframe where the coupler/centering joint is. Something else to fill unless it doesn't bother you. Not a big deal in the grand scheme. All that said my glue of choice for this purpose is no-shrink, no-grab Gorilla polyurethane. It's good to have choices.

 

[mh9162013]

Not familiar with that. It sounds like it’s for joining fabric together? How strong is it?

Fairly strong, from what I've read (it's at least stronger than using white or wood glue for plastic-on-paper/wood). I believe it has a solvent that helps melt the plastic, but still lets the glue seep into the wood/paper grains.

 

[flyingeagle]

Just had a thought. I have read a post that if you don’t get a 2 part epoxy mixed just right that gluing a motor mount in won’t hold and could come loose. The mix will have perfect. Is something to worry about. When I mix it I try to get as close as I can in equal parts

 

[flyingeagle]

I have had several times they dreadful BT pucker from the glue inside. Just more time consuming to fill in with CWF.

 

[mh9162013]

Just had a thought. I have read a post that if you don’t get a 2 part epoxy mixed just right that gluing a motor mount in won’t hold and could come loose. The mix will have perfect. Is something to worry about. When I mix it I try to get as close as I can in equal parts

What @Antares JS said earlier: You're over thinking things.

 

[flyingeagle]

I have built rockets in the 90s and I will agree since I got back into rocketry in 2015 yes I have taken up another hobby (over thinking). This has slowed down my builds considerably. I sometimes feel like I lost my confidence in building them. I use to build and glue and glue and build but now it seams more complicated than what it was back then. Ten different types of glue. I tried everything on not only sealing and strengthen the fins in which I now paper them but another problem. The rest of the balsa fins or other wood parts are to small to paper them so now what. I have around 250 kits staring at me saying, hay when are you going to build me!? I just worry about a motor mount failing or something out of alignment. I thought this was supposed to be a fun relaxing hobby?

 

[Hobie1dog]

This thread was started in 2007, and the OP hasn't been on here since 2008(15 years). Gotta love forums.

 

[mh9162013]

I have built rockets in the 90s and I will agree since I got back into rocketry in 2015 yes I have taken up another hobby (over thinking). This has slowed down my builds considerably. I sometimes feel like I lost my confidence in building them. I use to build and glue and glue and build but now it seams more complicated than what it was back then. Ten different types of glue. I tried everything on not only sealing and strengthen the fins in which I now paper them but another problem. The rest of the balsa fins or other wood parts are to small to paper them so now what. I have around 250 kits staring at me saying, hay when are you going to build me!? I just worry about a motor mount failing or something out of alignment. I thought this was supposed to be a fun relaxing hobby?

The "tyrany of choice," I get it.

It is a fun and relaxing hobby. Of course, you can choose not to make it that way, if that's your choice (or compulsion).

I learned a very important lesson from model rockets that I think I read somewhere on here: "perfection is the enemy of good." Keeping that in mind might help you put less pressure on yourself.

 

[Hobie1dog]

. I have around 250 kits staring at me saying, hay when are you going to build me!?

WOW, you obviously had a much different profession than what I had through the years. Congrats