Tattoo

After over 300 wings...my guess is it sets up in less than 30 seconds, but I usually give it a minute or two before letting up on the pressure just to be on the safe side.

vertigo72480

I guess that Tattoo has better coro than I do. If I stand there and hold the wing for five minutes, then let go, it still pulls apart. I glued my first wing last night and let it set for about half an hour b4 I let them up. This morning, I found that the bond on the right side of my wing, which is blue had let go on the inner 8 inches. So I put it back on the bench and glued it again during my lunch hour.

I'm getting addicted to this!!!

i'm gonna keep it under pressure for like the next 4 or five hours until I come home from work tongiht.

Mike

tinker-RCU

before my retirement i worked in the sign bus. we had many customers who used formed sign faces. most were formed with lexan which is a polyurethane. before being formed we had to hang the face material in the gas oven overnight to dry out the moisture that the poly. has a tendency to absorb. we formed the copy in the face or used silicone. there was a two part glue that had to be kept in a freezer, very expensive. coro is polycarb....
why can't you just silicone it?? as long as your not flying in real cold, freezing, the stuff is really as strong as anything in the hardware store and is kind of flexible. should work fine. just my 2 cents. i have a sheet waiting for me to turn into airship.
tinker

Tattoo

If your having trouble...and have the wing clamped down...spray some water from a squirt bottle inside the wing on the glue. Works as good as accelorator. So much so, I've used this method on the Corospit and other closed wing tip planes for closing the tips. I also do this on the edges of stubborn wing wraps...anyone who's put a wing wrap on a dihedral wing knows what I mean.

ChrisSpad

yep. If you don't mind the wait, goop works well also.
And, for extra insurance, you can always run zip ties through the wing skins and inboard aileron sections to hold it together.

But, with scotchbrite and mineral spirits, and a few hundred (honestly have lost count) wings, i've yet to have one pop loose with that configuration.

The Beast-inactive

There is a material out there that will fuse plastic together. It is similar in composition to the liquid glue used in plastic models. It is called MEK or methyl ethyl ketone. I use sometimes for bonding acrylic sheet. Nasty stuff. It works but it is not condusive to your health. I haven't tried it on coroplast. Might work if it's plastic to plastic bonds. There is stuff out there guys but just be damned careful. I'd rather seeing you out there flying and not in a morgue. Take care all.

vertigo72480

If at first you don't succeed...

Well it seems my second go at glueing that damned blue coro worked this time. not sure if it was the time or what, but it be lotsa stronger that the first time, yesir!

So, tonight, I glue on my ailerons, and center wing wrap, and then I wait for my engine.

Mike

ChrisSpad

MEK won't melt coroplast. Nor will acetone. As a matter of a fact, neither do much of anything as far as prepping goes.

tinker-RCU

hey guys, i made a major screw up. i'm sorry about it. when i said coro is polyurethane i meant to say polycarbonate which is what we formed into signs. polycarb. is lexan, which is coro. i was thinking about makin a custom gas tank, got my tongue over my eye tooth i couldn't see what i was sayin...........
tinker

ChrisSpad

coroplast is polypropylene.

rchawaii

Don't use this on coro, you'll waste your time and money. Works great for building from acrylic though, which is what it was made for in this form.

I use CA, Handibond.com has PLASTIC CA. look them up see if you can get ahold of some of theirs to at least try it out. Works great for me!

HOOTER

OK Guy's I have figured this thing out I built three DPS wing's tonight, Sand it, Clean it with tacky cloth, Flame it, then put 5-minute epoxy on it . It will never come apart!!!!!!

By the way I don't need this many DPS wings but I have become the offical Spad builder for the WTRC, everybody wants one now!!

Later

rchawaii

I read this once again, and I suspect the problem is too much glue. You only need dots the size of a pencil eraser about 3/4" inch or so. It's nothing like gluing up that brown stuff that falls apart when crashed and gets carried home in a bag..

rchawaii

Congrats!!!!, Good luck on the job well done and hope you get lots of converts.

pinball-RCU

I agree. Unlike balsa, CA between two pieces of coro can stay liquid for a LONG time. I have peeled apart coro four hours after gluing and found the CA still liquid. CA cures by exposure to moisture and air, and there may be precious little of that way inside two pieces of coro. As a result, if the pieces move just a little in the curing process, you can end up with a lousy joint.

The reason I think the little drops of CA work so well, is that the CA hardens around the edges of the little dots reasonably quickly, holding the whole thing together until it all cures.

I would guess my drops are even smaller than the pencil eraser, but I space them closer, maybe 1/2" apart.

Captain351

Wood peckering the area to be glued greatly speeds up the drying time allowing both air and moisture to enter the joint.

rchawaii

Good point. Although I don't do this, many do with good results. My method is just sand, wipe off and glue. (Sometimes I dont even need to prep the surface) It works different for different people.

ALSO, you're right pinball, I should have said dots NO LARGER THAN a NO.2 pencil eraser. Mine are about half or less than that.

RysiuM

My Feedback: (1)

There is an update to my experiments:
For my first Corostang I cleaned the coro with mineral spirit, but my wife couldn't stand the smell, so now I don't do this any more. what I do is:
[sm=thumbup.gif] Coro to coro - Clean both surfaces with 300 sanding paper, run woodpecker, wet one side and put the layer of gorilla glue on the other (the stuff that makes a foam). I let it cure for about 1 hour.
[sm=thumbup.gif] Coro to wood - prepare coro the same way as above, wet the wood and put the Gorilla glue on the coro. It cures within an hour.
[sm=thumbup.gif] Coro to balsa - Sand the coro with 300 sanding paper, put medium CA on the balsa piece and press it to the coro. I cures within the seconds.

[sm=thumbdown.gif] Time showed, that hot glue melts in the sun and pills of the coro when exposed to the fuel. Not good. I have replaced it with Gorilla glue.

Capt_Kc

Welders Glue, found at Wal-Mart. It takes overnight to set up, but is really really good. I also bought some stuff called "oops" in a spray can I use to "flash" or clean the coro. It works good. It'll remove anything you want it to. I have a paint brush cleaner that I use to place the holes in the coro where it is being glued. Once cleaned and *****ed with holes, the welders glue is outstanding.

ZimboRaider

SO ultimately whats the best way of gluing coro for a beginner, explained in simple english? Maybe I am dumb but 1/2 this stuff I don't understand< for instance whats wood peckering??
Thanks

Capt_Kc

woodpeckering is a term tookin from a tool called a woodpecker. you can go to towerhobbies.com and do a search for it. Its a tool that has a bunch of pins on it to "*****" the wood or put holes in it, hence for calling woodpecker. You can use a t pin, or whatever you want to put holes in the coroplast. A woodpecker is just a fast way of doing it. I haven't really tried much of ways to do it. I know the welders glue you find at walmart works really good. Takes a long time to set up though.

emailbanter

My Feedback: (2)

I would recommend the "handiBond" CA brand. It always adheres to Coro where I've heard other guys having problems with other CA brands.

rchawaii

This how I've been doin it since I started. First make sure you have fresh CA. HandiBond PLASTIC CA (found at http://handibond.com ) I the best I've used.

I locate the area to be glued. Lets say the area is the wing fold area where the rons may be installed seperately. Lets say the rons are 13" long and 2" chordwise. I overlap the ron about 5 flutes to the coro on the wing overlaps. I sand all areas needing glue with about 120 grit sandpaper. (The grits not that crucial, as long as it's rough).

I then wipe the sanded area off with a clean cotton cloth. (Terri hand towel if you really need to know )

I then place a dot of about a 1/4 inch of CA about every inch or so, in some cases every half inch apart the whole length of the area to be glued. If you use (in most cases) a continous bead of ca, it tends NOT to cure as quick and the dot method seems plenty strong enough.

Then, I place (in this example) the ron in place CAREFULLY and QUICKLY, making sure it's exactly where I want it. I then hold this together (I do it by hand) for about 30 seconds or less in almost all cases. If there's alot of pulling pressure on the area, I weight it down, or clamp it for as long as I can to ensure it's not coming apart.

I have never had a join fail using this method of coro to coro bonding. Hope this helps some.