eltonhodges

My Feedback: (4)

Hey guys,
Just wondering if anyone has skinned a wing using Elmer's or any other polyurethane glue. I've noticed a lot of people saying they've used "Probond". All I can find in Probond is white and yellow glue. I don't belive it will foam and fill gaps, will it? I'm just wondering if the "Probond that everyone rave's about is some other glue that Probond makes, just in polyurethane, and I can't find it. Any help would be appreciated. Thanks. Elton

JB Rekit

My Feedback: (3)

I've used both the Elmers Ultimate and Gorilla glue. I liked the elmers better b.c it is a little thinner and spreads easier. I can vouch for the stregth too as I was just shot down and there was no balsa that was not still attached to foam. Once you can tell the wood is damp with glue, just keep scraping it off (or around to a dry area) as thin as you can. The nice thing about this glue is that it keeps expanding and the longer you wait the more glue you can scrape off. Just try to spend roughly the same amount of time on each wing so the amount of glue you use is consistant. I also just got another 16oz bottle to start my sheeting with on my new project.

John

quist

My Feedback: (198)

Elmers had both Ultimate and probond poly glues, they were the same glue. Now they just sell the Ultimate label.

OnTheEdge

Ulitamate Poly is the same as the old "Probond" poly glue. It'll work great plus it's a little less $$ that Gorilla glue. Just date the bottle when you get it. After a year or so, don't use it on planes (use it on less valuable household stuff ) as it has a shelf life.


...........Mark

JB Rekit

My Feedback: (3)

I never used elmers when it had a probond that was a polyurethane, but what they are now calling probond is a yellow wood glue like tightbond.

It says it is sander friendly so I decided to give it a shot gluing the sheeting together b.c I doubt I'm the only one who gets those occasional little balls of glue that roll up under the sand paper and put those little dent/scratches in the sheeting. I don't know what will be different with the elmers but I figure I'll give it a try and let you guys know how it works.

John

OnTheEdge

Yep, the Probond name that's now on the shelves is a yellow wood glue (and a very good one at that).

John, what I do is use a syringe to apply just a little bit of glue. Close the joint and then wipe off the excess then immediately sand it with a long t-bar sander then let dry. The saw dust fills the cracks and then when it does dry very little glue needs to be sanded and what's left sands very easily.

.....Mark

eltonhodges

My Feedback: (4)

Thanks guys, I'll go ahead and use the Elmer's. I just wanted to make sure that polyurethane is okay for the wing skinning. I wasn't sure if it was, or if I should have run out to get "Probond". It's almost too confusing when you go to buy glue nowadays. There must be 40 bottles of stuff that jump out at you. I do like the gap filling formula of polyurethane, so onwards and upwards. My Carden should be ready to go in a month or so.

JB Rekit

My Feedback: (3)

Mark

Thanks for the tip on sanding it while it is still wet. Makes a lot of sense, I've just always waited until it had dried, but will definately do it that way this time.

John

OnTheEdge

No problem, just double check the paper on your t-bar to make sure some dried glue from the first wing skin doesn't gash the second one. I take a small paint brush and immediately brush off the dust residue (which might have some wet glue in it as well) off the bottom of the t-bar when I'm done with that wing skin.

TommyWatson

My Feedback: (1)

I have always skinned my wings with epoxy (several BVM jets and others).
I have just received my new Carden 35% Extra and I would like to try the Polyurathane glue.
Can someone describe their method. Do you just put the glue on the skin?, or also on the foam. How much glue?, How long does it take to dry?. How much working time do you have?.

I have used Poly glue for woodwork on my trailer and it sure sticks.

Any other observations and comments would be appreciated.


Thanks

OnTheEdge

Hi Tom, First thing I do is mark small lines on the root and tip to line up the foam with the sheeting. This way, you can match the lines and know you have a nice amount of overhang.

What you want to do is apply the poly glue to the balsa sheeting only. I drizzled some on in a section in a back and forth motion and then use an old credit card to squeegy it around. Repeat till covered with uniform light coat. You want the entire surface to have a light coating. You will end up squeegying a lot of the glue off the skin when done. Make sure you have good even coverage right up to the edge. Also, using the reflection from a light, make sure you have covered the entire surface. Move the sheet around and look for the glossy reflection.

Then you want to mist the foam surface with water. You just need a slight bit of moisture to activate the glue. I use an old spray pump bottle from cleaner for eyeglasses. It gives a nice mist as apposed to a heavy spray from a windex type spray bottle.

Then you just put it in the shucks as you would have done with epoxy. Line up the lines and weight it down in the shucks. Check every few minutes for the first half hour or so to make sure the sheets didn't slide (another reason you don't want too much water on the foam).

It's not a bad idea to have two people to do sheeting. This way you can work quicker and line up the sheets correctly the first time.

I'm not sure of the work time, but I did just one wing panel (foam and two sheets) at a time and had plenty of work time. Dry time can vary based on the amount of water and the humidity but I'd let the wings and stabs/rudder sit for at least 20 hours or so. They may have been dry after 12 but I figure, why risk it.

You might want to do a goggle search as I recall reading a good article on probond sheeting somewhere on the net.

Hope this helps............Mark