dbruening80

My Feedback: (1)

Something that I've been doing on foam wings when sheeting them is to run a "woodpecker" tool over the core. If I am using PU glue, I don not use the woodpecker as I am concerned the glue may force itself through the tiny holes. Basically the woodpecker creates tiny holes in the foam and forms "rivits" once the glue is cured. Just a thought.

southern_touch9

My Feedback: (3)

For holding the wood and foam together its simple...cans of beer. When you get done drinking all 48 then its time to move to the next step

scolpit

I think im gonna buy a 65" yak, but im a little worried about the glue i should use on foam. Where i live i do not have access to many glues... i have access to epoxy and white glue only. Do you (OMP) sell Gorilla glue? I just need a little glue, ill make it thinner than possible I like white glue because its not a fast glue, its cheap, and i have it a lot. How does white glue reacts with glow fuel? Can i use it without any problems? Thanks.

southern_touch9

My Feedback: (3)

Is there a reason nobody has used foam safe CA. I understand that the glue has to go deep into the foam but why not wood pecker it. It cures slow for CA but really fast for any of the other options.

flybyjoe

My Feedback: (1)

I have never used gorilla glue, don't know as I've even seen any. The "sourdough glue" was good in it's time. However, I have cut and sheeted 25 to 30 wings in the last twelve or so years and always used 30 minute Z Poxy, one ounce per wing on good sized ones. I spread and carded the sheets only, for both sides, put it back in the cradle, and weighted them down with steel plates. If I run out of plates, doing several wings at one time, I used some ply and cement blocks. I've never had any slide, bubble or peel and never had any complaints from the recipients so, that is what I recommend. Oh, and I never dreamed of using anything as heavy as 200 lbs. or more. Seems to me that'll squish things up pretty good. lol []

mmattockx

For those who are unsure of the polyurethane glues, check out this excellent page on pattern wing construction (he adds only about 18g of glue to a 500sqin panel!):

http://www.mackrc.net/patternwings2/index.htm

For those who think that 200lb is too much weight, vacuum bagging applies MUCH more than that. 5" of vacuum is just under 2.5psi. On a 500sqin wing (half of a 2M pattern wing), that equals a load of 1250lb. And it will not crush even 1lb white foam...Good stuff for getting the best possible bond.


Mark

flybyjoe

My Feedback: (1)

A few years ago, my son and I were cutting foam wings for customers (as AEROSMITH MODEL AVIATION). We used 30 min. epoxy carded on the sheeting, back into the mold and weighted with flat steel bars. I don't remember how much weight but sufficient, and on most wings, we only used 1 oz of epoxy per wing panel. Needless to say, we did many sets and never had a complaint of quality nor function. Nor did we ever have any sliding or bubbling. Personally I feel this is an easy, simple method and if something ain't broke, don't fix it. Of course there are other methods and all of them probably would work if done properly with diligence and common sense.

flybyjoe

My Feedback: (1)

Well, I guess I'm gonna have to face it. I am getting OLD! I'm sorry fellas (and gals). Seems I have repeated myself to some extent. Didn't even remember responding to this blob before. However, as long as i'm here again, another item that may be useful to someone,. . . to make sheeting, we sanded straight edges, taped the 3" & 4" strips with masking tape on one side, turned them over and used thin CA down the seam. The tape keeps the CA from going all over the place and when you remove the tape, you have a seam that is sandable and of course there are three rules to sanding, my son always told me, and they are: 1. don' t press, 2. don't press and 3. DON'T PRESS!

mmattockx

Joe,

That is a very valid and time tested method. I could never get proper coverage on my larger wings with only 1oz of epoxy (my problem, not the method), where the polyurethanes add even less weight and are easier to get full coverage with. If you could get the epoxy to work, the the poly glues may not be an improvement. For those of us who could not get satisfactory results with epoxy, the poly glues are a better choice. YMMV


Mark

flybyjoe

My Feedback: (1)

Yo Mark. At that time I had little or no experience with poly glues. I'm not even sure I know what they are exactly. I did have some experience with Dave Brown's Sorguhm and it worked but I didn't think as sure and easily as epoxy. You're probably right about youre poly glues. In any case, what ever works best for you and WORKS, that is the main goal, right? Like I said, to be sure anything works, it at least requires doing it properly, which includes preparation. It's similar to covering a plane, . . what ever you leave underneath, you're gonna have on the top. If you prepare it properly, you'll have a beautiful finish. Thanks for the comeback, Mark.

Joe

scolpit

I used Poly glue on my yak. Its really easy to use. It was hard to find this glue here in Portugal. But i still have one question about this glue. Is it glow fuel proof?

PlanePlanter

My Feedback: (9)

No it's not. You still need to coat all exposed wood with some thinned epoxy or CA (Be careful with the CA @ the foam)

flybyjoe

My Feedback: (1)

I'm only guessing but from reading articles in this site, I would say probably so. I would assume that Titebond wouldn't make anything that wasn't. However, Mark should be able to help you out on this. By the way, there is a very good post by Tony Hallo of Springdale, Penn. on cutting foam wings like I use to, and he also refers to his usage of poly glue. Oh, it's headlined Foam Wings! lol

flybyjoe

My Feedback: (1)

Hey, there you go, Scolpit. An adament answer with conviction and an essence of experience. I do know that there is a foam safe compliant CA. A little more expensive, but worth it in some cases.

PlanePlanter

My Feedback: (9)

HHHmmmmm, I was in a hurry when I posted.
Maybe a flat out no is the wrong answer (heaven knows I have been wrong before and will be again)
In my experience, oil still seeped into the balsa in areas where I had used poly glue. Now I will also tell you this, it was in a repaired area of the plane and one of the first few times I had ever used poly glue so maybe something else was going on. I have used poly glue many times since with excellent results but I also make sure to use thinned epoxy on any and all exposed wood and openings. So I'll retract my "no". And yes foam safe CA would be well worth it.

kenh3497

I started the hobby back in 1975. I have used contact cement, white glue & variations of white glue, epoxy and now for the first time Poly glue. I'm back from a very long layoff to the hobby, about 10 years. After reading many threads on using poly glue I have to say it is easier to use than epoxy, adds less weight than epoxy and appears to just as strong as epoxy. Another upside to the poly glue is it will fill any voids. You apply it just like epoxy. If the surface is "shiny" you have too much on. It is looks "dry" you need a bit more. I used about 50 pounds of weight on a 200+ square inch wing. That seemed to be enough weight. Will I use ply glue again, You Bet!!!!

Ken

captinjohn

I like the "woodpecker method. Every time I done that on wood to wood....the wood act like on piece whentorn apart. Far superior than surface to surface thin glue joints. Capt,n.

ochsnm00

My favorite for wing cores is 3M 77. If you spray lightly on the foam it won't melt it. Spray it on the balsa and let it dry a few minutes. Now on a flat surface roll the foam onto the balsa. You have to get it right the first time. Practice on some test pieces first.

Greg Wright

My Feedback: (6)

Gorilla Glue is the best glue for for this.

ochsnm00

Too expensive and too fast.