Glues

I would like start a discussion on glues.
I have always used epoxy for the most stressed parts of my models. I.e., the motor mounts, landing gear, wing to fuselage connection, bellcrank, etc.
However, while reading one of Tom Morris' construction articles, I noticed that he uses only "Elmer's Glue-All" for all parts. He is an expert builder and I value his judgement. So I am switching to Elmer's, which is less messy and water soluble. Any opinions?
Fernando
Fat, Dumb and Happy.

i use elmers carpenters wood glue almost exclusively. you sure he uses glue all and not the wood glue? the wood glue is slightly stronger, and lots easier to sand. i do use the glue all when i need a thinner glue. i like that i can use a syringe to get the glue into tight spots, clean it out with water, and use it over and over. you can also smear a layer on both pieces, let them sit for a couple of minutes, then they stick together sort of like contact cement, only not. you can let it dry then iron it, the heat will polymerize the glue, and it is stuck.

sorry about not using caps, i'm wrestling the 7 month old with my left hand.

I used tightbond back when I was into free flight. Now I use ambroid and double glue, Im not in a hurry anymore. I did like the way letting the tightbond dry slightly would stick as has been mentioned. What I REALLY want is some of the DuBro super cement from 20 years ago. That was the best stuff ever!

I for one, do not believe any single adhesive is all encompassing. Each type has its place. I use epoxies, Elmers, Tight Bond, Ambroid and the various speed AC or ACy glues. The ply doublers and motor mounts I use epoxies. On some ribs I use AC or Elmers. On cloth hinges I prefer Ambroid. It makes me take my time and do it right. Also for pure nostalgia, but the stuff works. For nylon hinges I use epoxie (very carefully). I no longer use LePages muselage. Tried it in 1947 on a solid balsa Hell Cat and discovered, thanks to Mom, Duco Cement.

Don't forget the polyurethane glues. I use those for laminating doublers and such.

I use a lot of Titebond-type glues, mainly because I build with foam.

Since the late 50s I've used Duco on 99% of the doublers and still sometimes build the whole plane with it. If I just tack a plane together with CA I'll follow up with the Duco. I quit using epoxy because Duco and CA have never come apart on any crashes or from flying. About the only time I use epoxy is when I crash badly and need to gap fill the ragged edges. Duco held up on several of my 60 size RC aerobatic planes and that was a lot harder on the airframe than my CLs ever could be. I follow the instructions...coat the parts first and let it dry, then apply the second coat and clamp. I also used Elmers Carpenter Glue (off white) a couple of times with good results but it takes too long to dry. If Duco dried faster I'd use it 100% of the time and forget the CA. Sigment seems weaker but it has never come apart either.

>Don't forget the polyurethane glues. I use those for
>laminating doublers and such.
>
>I use a lot of Titebond-type glues, mainly because I build
>with foam.

Isky,

I just picked up some polyu glue the other day based pretty much on the label that says it'll glue "anything". I'm thinking about applications like gluing plastic canopies on, etc.

What's been your experience with these glues and what are the pluses and minuses.

Well just like anyone else, we all have our opinions on this subject. I still and will always use the proper glue in the proper place, period. Epoxy glue for the mounts and doublers is the only way to go. Epoxy glue doesn’t get brittle and retains a small amount of flexibility. Unlike carpenters glue (yellow or white) they become very brittle (that is why they are easy to sand) and you need the flexibility to absorb vibration. Having said that, on small engines (.35 or smaller) there may not be much of difference. The CA glues are also brittle and should be used sparingly in high stress areas. Although I have personally built many models entirely with the CA glues and they have stood up for many years. Double gluing was a common practice years ago when using Ambroid or Duco glue. This allowed the glue to penetrate deep into the pours of the wood before assembling the parts.

I'm with Mikey on this. Use the glue that's approriate for the job. Epoxy for the motor mounts, Pica Gluit for external seams, CA to tack and "move along" with construction. The Pica Gluit sands very weel and I can feather an edge that is glued with it.

Thanks Mikey,
I have a profile with a ST 46, it's about 7 years old. I noticed it was vibrating more than usual. I used titebond at the wing to fuse joint I had used leather fillets and the paint on the surface of the fillets was cracking. So as not to absorb oil I stripped the fillet on one side with the intent of replacing it. WOW, much to my surprise the titebond had turned to hard little pieces that just fell out when I turned the plane over. This joint was not a tight joint and I had filled the 1/8 gap with titebond which was a bad idea. Should have stuffed with balsa and epoxied. I never knew how brittle the tightbond would become (lesson learned).

What MIKEY said. It's not rocket science...it could be...but it's not. Also CA glue is heavy and really one coat of CA is Necessary any extra is just weight.
SIGMENT, DUCO, TIGHTBOND, ELMERS wood Glue, and 5 min epoxy seem to be my FAVS.

Scott(where's the kicker!)Riese

When I first started out 3 years ago, I used only wood glue and thought epoxy and CA were way too expensive, and hey, wood glue works okay...

Now I have 3 different kinds of epoxy, plus CA and wood glue, and I use each one depending on the job at hand. I'm no expert with them, but I have discovered that the epoxy and CA last so long they really are pretty cheap in the long run. At first I just bought the $5 5-minute epoxy syringe from Canadian Tire, but the first time I sprang for a 4-oz set of Hangar 9 30-min epoxy, I was hooked!

Sigment, epoxy and CA, depending on application.

Good old model airplane cement (Sigment, Ambroid, others) is still useful, at least to me.

It is light, cheap, and sands so, so easily.

Do I use it for bellcrank platforms, or around motor mounts? No.

Epoxy, CA, Pica Gluit.

I have to agree with Mikey also. I always use epoxy for the high stress applications, most of the other structure is built using CA. I normally go back through the wing a double glue the wing joints with more CA.
However, I don't buy into the fact that CA is heavy or brittle if used correctly. You would have to be using a ton of super thick CA to notice any weight increase. If you are using CA for balsa to balsa joints the wood is more brittle than the CA.

My pal Doug would CA Team Racers together, only place for epoxy was engine mounts, and a small fillet at the wing root. Some hard landings disassembled a couple, looked like the airplane exploded. CA has its place, but should be augmented with some flexible adhesive in vital 'zones'. (I still like Ambroid, too)

I use The new polyurethane for gluing up combat foamies. it is the strongest Ive seen, maybe stronger than epoxy with the penetration from the damp wood style of application, it do get ugly if you use too much, foams out everywhere. I ve had some joint failures with the white glu,. . Not with the poly stuff.
MM

If you want to really try something different - some of the Texans are building CL Combat planes using 3M77. Yup, the spray stuff. Very light, very fast. You can supposedly put a Lighthawk kit together (including the covering) in about 2-3 hours doing this.

>I'm with Mikey on this. Use the glue that's approriate for
>the job. Epoxy for the motor mounts, Pica Gluit for
>external seams, CA to tack and "move along" with
>construction. The Pica Gluit sands very weel and I can
>feather an edge that is glued with it.

Crist,

I'm not familiar with the Pca Gluit. What type of glue is it and where do you get it?

Ted I get it at the local hobby shop,it's the best aliphatic glue
I've ever used. Sold by Pica Products Miami Florida.

Walter:+

Listen to Mikey, he knows of what he speaks. Its important to use the right glue for the right job and also to not use the WRONG glue for a specific application. For example- do not use thin CA for the trailing edge sheeting. It will most likely come out uneven with dips. On one of my early finished models, Mikey took a look and said, "you used CA on the trailing edge sheeting, didnt you?" He was right. I'd go with Mikes advice.
Brian

While on the subject of glues... Most of what has been stated here is good stuff. But I think I've found some "specialty" glues worth mentioning. PACER (ZAP) has several really good products you might want to experiment with. (I found these two to be great, but y'all are entitled to your opinions). Try "Formula '560'" canopy glue. Tried RC-56, and the like, to no avail. but the "560" works! Also play with PACER's "Hinge Glue". Far easier than epoxy, and seems to work very well.

I've been using the RC-56 only for canopies and had good results. No problems after 10-12 yrs anyway.

What type CA are you guys using? I use only thin and and seem to have better results with the ZAP brand...it will glue plastics, velcro and other weird materials together better than the other brands I've tired.

Circle Burner,

A lot of us used to think that CA was a fairly light glue. Not so. It certainly is not as heavy as epoxy but it is heavy enough that I try to avoid it as much as possible.

For those who insist on use of CA, yet want to avoid excess weight from the glue, one of the best tricks is to use "medium," to only rarely use the "thin" stuff. With the former one can control where the glue goes and so how much is used; with the latter it just goes everyplace, even places where there is no glue joint or even a need for glue of any sort and sucks up the stuff like a sponge.

Iskandar,

Tell my Texan brothers we were using 3M 77 Spray Adhesive to assemble CL Combat models many, many years ago.

I've always used the thin stuff. I figured that using gap-filling glue admitted a lack of craftsmanship. Loctite 410 is nice for bonding carbon composite, though. The color matches, and the rubberiness keeps the bonds from being brittle.

Hmm,

I use everything. Mostly CA of one type or another. Some white, very sandable stuff I don't remember the name of, but it's about gone so I'll probably need to get some more and epoxy very sparingly.

I figure the less glue used, the less weight added.

Whoops, almost forgot. I'm trying West Systems 105/205 epoxy with the 410 filler for fillets this time. Sure is a lot lighter than previous materials. And it sands pretty easily too.

I first started using ca about 10-12 yrs ago on a 40 size rc ship. I crashed it and broke the entire nose off at the front of the wing...several times. The first time I repaired it using T88 structural epoxy, which is what I also used to build a wood 30'wingspan ultra light airplane with. T88 is way stronger than Tower Hobby epoxy if smashing both with a hammer means anything. I just butted the nose back and glued it. It held and the next crash broke the nose off an inch or so fwd of the epoxy joint. The second repair was intended to be a ca experiment and I used only ca with the same butt type joint (no reinforcing). The last crash broke off the nose in front of the ca and didn't bother either of the repairs. After that I decided ca was pretty strong.

I agree CA can be heavy if you use a ton of it on every joint. If you were building a free-flight rubber model you might have to be concerned. But with your larger R/C or C/L models unless you get carried away your not going to notice weight increase from using CA versus a wood glue of some type. Next time weight the bottle of CA before you start the model and after you finish to see how much weight you really added.

Great info on this thread!

Speaking of the right glue for the application...I have been using the Mid Cure 15 Minute Epoxy for doublers and wing installation, F1 and F2 formers for a very long time. This glue handles the vibration around the nose section very well with no delamination, cracking etc.

Fernando,
I sometimes used Elmer's Glue-All for total model assembly back before CA was available and very few were using epoxy. IMHO it works well. It is thin enough to penetrate the wood and form a strong joint. It is, however, terrible to sand and slow drying. If laminating sheets with it you should clamp or weight the joined area to prevent warps while it dries. When I started using aliphatic resin like Titebond, etc., it was because they were faster drying and sandable.
I have used urethane glues for wood projects other than models but very little for models. As someone mentioned previously it is very strong but watch out for expansion. Gorilla glue says, "Strongest glue on planet Earth".
Still hard to beat Ambroid and Duco, if they are applied properly (double cemented).
I use thin, med, and thick CA...but mostly medium.
I use epoxy for motor mounts, firewall, etc.

Just another opinion. Individual results may vary.

Is there a CA that works on Coroplast without flashing the Coroplast first?