Sheeting Foam
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Sheeting Foam
I am about to sheet my foam wing with Pro bond wood glue. The consistency is thick, and I was wondering if I should water it down so it flows better. My main concern is that the glue will be thick in spots.
Craig.
Craig.
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Sheeting Foam
Are you using the probond POLYURETHANE glue? Probond is a family of glues that includes aliphatic resins also.
The polyurethane is like maple syrup. Spread it on the balsa skins and spread it out thin with a credit card. I have never needed to thin it for this application.
The polyurethane is like maple syrup. Spread it on the balsa skins and spread it out thin with a credit card. I have never needed to thin it for this application.
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Don't thin it out with water. Water starts the foaming/curing process if it is the Polyurethane version , if you add too much you might get too much foaming action. It goes on easy enough as it is.
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I am using just standard Probond Carpenters glue. I applied it to the foam and it was a lot of work to smooth out. I will apply it to the balsa, which will work better. Any ideas how long I should leave it pressed with the weight on?
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You should leave it in the weighted shucks a long time if using any water based alphetic resin (yellow or white). The remaining water has been known to make the wood/wing warp in unpredictable ways if removed too soon prior to the wood/glue fully curing. I would leave it in at least 2-3 days if not longer. This is not a problem with either epoxy or the polyurethane Pro-bond. They both go off chemically and are fully cured in 24 hours. If it is not too late... I would suggest either Polyurethane Pro-bond or a good finish epoxy like Z-poxy or West Systems as a better alternative. Good luck.
dan
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Sheeting Foam
Pro Bond polyurethane looks like honey and is just a little thicker. It smoothes out nice and thin with an old credit card. All that is required is a consistant thin film on the balsa. Mist the foam core with water and apply the glue coated balsa. I do not even edge glue my balsa sheets any more. All I do is make sure they fit together well and tape them together. The tape goes on the outside of course. When the glue kicks and starts to foam it will creep in to the joints of the sheets and glue them together solid. It makes for an invisible seam that sands as easy as balsa. Ever try to sand a CA glued sheet joint?
Vince
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Vince,
How thin of a coat do you need? I saw some other comments that scraping down with a credit card does not leave enough on. I saw another post where it was applied with a spreader with notches cut in it.
I just finished mine, and I am concerned that I didn't scrape enough off. It pushed itself through the balsa skin and out the edges. Nothing that sanding wouln't fix, but I am worried about its weight. Looking for advice for next time.
Thanks,
mark
How thin of a coat do you need? I saw some other comments that scraping down with a credit card does not leave enough on. I saw another post where it was applied with a spreader with notches cut in it.
I just finished mine, and I am concerned that I didn't scrape enough off. It pushed itself through the balsa skin and out the edges. Nothing that sanding wouln't fix, but I am worried about its weight. Looking for advice for next time.
Thanks,
mark
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When sheeting a foam wing scrape as much off as possible... there should be no shiny spots with either epoxy or probond. It dosn't take much and anything else is just excess weight.
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I had problems with sheeting my wings too. I used some contact cement that didnt work at all. After starting over, I found some stuff called Southern's Sorgham. You can get it on tower's website. I think its around $5. That is the best stuff. I wouldnt recommend anything else.
Bottom line... make sure the stuff is right the first time so you dont have to start over.
Mike
Bottom line... make sure the stuff is right the first time so you dont have to start over.
Mike