Have you used PC on silkspan over open bays? What did you do and how well did it work?
Polycrylic over open bay silkspan?
Stuka Stunt Main Forum · 5 of 5 known posts recovered
I'm wondering the same thing. Also, can it be used as a dope substitute for attaching silkspan?
I need to re-cover a model with enamel-soaked balsa in some spots. Dope would react with the enamel and cause crinkles in the finish. Would Polycrylic work ok?
I need to re-cover a model with enamel-soaked balsa in some spots. Dope would react with the enamel and cause crinkles in the finish. Would Polycrylic work ok?
Aaron Nottingham · Jul 17, 2003 07:14 PM
#2 source
>I'm wondering the same thing. Also, can it be used as a dope
>substitute for attaching silkspan?
>I need to re-cover a model with enamel-soaked balsa in some
>spots. Dope would react with the enamel and cause crinkles
>in the finish. Would Polycrylic work ok?
>substitute for attaching silkspan?
>I need to re-cover a model with enamel-soaked balsa in some
>spots. Dope would react with the enamel and cause crinkles
>in the finish. Would Polycrylic work ok?
I just covered a wing with traditional dope and silkspan, but I shrunk the open bays with only two coats of dope sprayed on. The outside perimeter had only the initial dope when tissue was applied. Then I covered the whole wing with PC. Let dry, lightly sanded, one more coat, lightly sanded, ready for primer. I have a practice wing that I will be using for a test. All PC application. I will post results. Thanks, Aaron.
>I'm wondering the same thing. Also, can it be used as a dope
>substitute for attaching silkspan?
I tried attaching silkspan over open bays with it and while it worked, I didn't really like it as well as the old tried and true method with dope. That's just application technique. It does seem to me that silkspan over balsa with a couple of coats of PC before the filler is easier to sand without cutting through the silkspan on corners and edges. That's why I wanted to find out about peoples' experiences using it over open bays and how they applied it. It has been said that PC is "harder". I don't think I quite agree with that choice of words to describe it. The composite texture is not brittle-hard like a glass or even like balsa saturated with CA glue. (A piece of glass is "hard". It is also brittle. A piece of aluminum is "hard" but it is a lot less brittle than the glass.) PC composits seems to me to be more of a plastic like texture. "Plastic" in the sense that there is some flexable quality to it. I'm wondering if that slightly flexable quality might make it less likely to crack around fillets and fuselage/wing joints or area where vibration causes cracks in a more brittle finish. The various substrates (i.e. balsa, silkspan, etc) become much more consistant in hardness and thus easier to sand to a smooth, even surface when filled. The filler sands more easily than the PC filled substrate. So in that sense it is "harder". I molded the leading edge sheeting for my Chipmunk-in-work by attaching 00 silkspan to 1/16th balsa with PC, let it dry for a couple of hours and wrapped it completely around the leading edge. Worked like a charm. The Balsa molded easily around the rather tight radius of the leading edge without any problem. I don't have any personal experience with long term durability of finishes using PC in the process.
>substitute for attaching silkspan?
I tried attaching silkspan over open bays with it and while it worked, I didn't really like it as well as the old tried and true method with dope. That's just application technique. It does seem to me that silkspan over balsa with a couple of coats of PC before the filler is easier to sand without cutting through the silkspan on corners and edges. That's why I wanted to find out about peoples' experiences using it over open bays and how they applied it. It has been said that PC is "harder". I don't think I quite agree with that choice of words to describe it. The composite texture is not brittle-hard like a glass or even like balsa saturated with CA glue. (A piece of glass is "hard". It is also brittle. A piece of aluminum is "hard" but it is a lot less brittle than the glass.) PC composits seems to me to be more of a plastic like texture. "Plastic" in the sense that there is some flexable quality to it. I'm wondering if that slightly flexable quality might make it less likely to crack around fillets and fuselage/wing joints or area where vibration causes cracks in a more brittle finish. The various substrates (i.e. balsa, silkspan, etc) become much more consistant in hardness and thus easier to sand to a smooth, even surface when filled. The filler sands more easily than the PC filled substrate. So in that sense it is "harder". I molded the leading edge sheeting for my Chipmunk-in-work by attaching 00 silkspan to 1/16th balsa with PC, let it dry for a couple of hours and wrapped it completely around the leading edge. Worked like a charm. The Balsa molded easily around the rather tight radius of the leading edge without any problem. I don't have any personal experience with long term durability of finishes using PC in the process.