Sheeting Foam Wings question
#3
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RE: Sheeting Foam Wings question
ORIGINAL: R8893
I've gotten good results with polyurethane glue (Gorilla Glue) for this application. Squeegee out to a very thin layer.
I've gotten good results with polyurethane glue (Gorilla Glue) for this application. Squeegee out to a very thin layer.
#4
RE: Sheeting Foam Wings question
Read this tutorial before you sheet with either laminating epoxy (which is the traditional choice) or PU glues (the new favorite and also an excellent choice). Also note that there is a Lepages Pro Bond PU glue that is the same stuff as Gorilla glue for about 1/2 the cost. Available at most Home Depot type stores. Terry Brox's wing building page is the best how to I have ever seen on balsa/foam wings and should be required reading before trying it, excellent stuff...
http://www.mackrc.net/patternwings2/index.htm
Mark
http://www.mackrc.net/patternwings2/index.htm
Mark
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RE: Sheeting Foam Wings question
Use lots of weight. A previous post says to use 40 pounds. I try to get at least 2 pounds per square inch. So a 10 x 40 inch wing would have 400 square inches assuming it is built in one piece. This would need 800 pounds of weight. I have since gone to a vacuum system which will deliver this much pressure without handling all the weights. I use polyurethane glue (gorilla glue or elmers polyurethane wood glue (formerly called Elmers Probond).
#7
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RE: Sheeting Foam Wings question
DMcQuinn....
Were did you get the vacuum system from? I don't have that much weighting around and was thinking of going that route instead of spending money on the lead shot, weight plates, or a ton of books! Will the vacuum system work conventional wings also? Thanks for the inputs.
Were did you get the vacuum system from? I don't have that much weighting around and was thinking of going that route instead of spending money on the lead shot, weight plates, or a ton of books! Will the vacuum system work conventional wings also? Thanks for the inputs.
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RE: Sheeting Foam Wings question
The vacuum "system" is simply a vacuum pump. I bought mine from a neighbor. A new one is usually over $100 but if you can find a used one they can be had for cheap. Then you just need some plastic tubing and a sheet of plastic (like a dropcloth sold at the discount store). Fold the drop cloth in half and seal the other three sides with a sealant (i use either tape or sometimes a cheap caulk). Also, most vacuum pumps have "too much" vacuum, so you need a regulator that goes between the pump and the bag. If too much vacuum, it will crush the wing. There's no using a vacuum pump for built-up balsa wings.
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RE: Sheeting Foam Wings question
I have used PU but because of the large weights and long wait have returned to Sorghum.
I first edge glue, with thin CA, the balsa sheet to give the necesary width. Then spread the Sorghum thinly on foam and sheet (useing a 'pretend' credit card) and leave to dry. When both are dry to the touch roll the sheet on while pressing down. Make sure it lines up, because once contact is made - it's stuck. It then ready to be trimmed for LE and TE.
I first edge glue, with thin CA, the balsa sheet to give the necesary width. Then spread the Sorghum thinly on foam and sheet (useing a 'pretend' credit card) and leave to dry. When both are dry to the touch roll the sheet on while pressing down. Make sure it lines up, because once contact is made - it's stuck. It then ready to be trimmed for LE and TE.
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RE: Sheeting Foam Wings question
yeah, pile on the weight. This is were them old phone books (or the complete Thomas Register!!) come in handy! If you can, get some wood (old shelves) on top of the shucks, to help distribute the weight.
Make sure you glue-up surface is flat, otherwise you can induce a twist. Some will induce a twist to get a desired amount of wash-out at the tips.. I perfer not to stack one on top of teh other.. do one at a time..
For the skins, edge glue them with wood glue / white glue. It's a lot easier to sand, and dosne't present a ridge like you'de get with CA. Sand both side of teh sheet prior to applying. I just find it easier to get a good smooth finish before applying the skins. Sand [lightly] the cores too! But remove the dust!!
My first wing, foam core lead to a b-a-a-d experinece.. A freind & I were gluing up the skins onto the cores. We whipped up a lot of epoxy, and slathered it on the cores. We got the cores & skins in the shucks, and all was set. I leaned over to see how it was going, to ensure taht all was alingned. As I leaned over, I placed my head squarely in the epoxy mixing pad. Since I was the weight, and we had obnly about 10 minuts working time, I had to watch the epoxy cure in my hair. The next 2 weeks, i was pulling epoxy out of my hair...
Make sure you glue-up surface is flat, otherwise you can induce a twist. Some will induce a twist to get a desired amount of wash-out at the tips.. I perfer not to stack one on top of teh other.. do one at a time..
For the skins, edge glue them with wood glue / white glue. It's a lot easier to sand, and dosne't present a ridge like you'de get with CA. Sand both side of teh sheet prior to applying. I just find it easier to get a good smooth finish before applying the skins. Sand [lightly] the cores too! But remove the dust!!
My first wing, foam core lead to a b-a-a-d experinece.. A freind & I were gluing up the skins onto the cores. We whipped up a lot of epoxy, and slathered it on the cores. We got the cores & skins in the shucks, and all was set. I leaned over to see how it was going, to ensure taht all was alingned. As I leaned over, I placed my head squarely in the epoxy mixing pad. Since I was the weight, and we had obnly about 10 minuts working time, I had to watch the epoxy cure in my hair. The next 2 weeks, i was pulling epoxy out of my hair...