baby powder ratio?

[Maz]

When mixing baby powder and polycrylic, what the ratio? I`m putting it over foam for a smoother paint finish. Also, how many coats do most people use?


Thanks,Dave

[usmc_VTOL_mech]

Maz
I have heard most people are using the baby powder mix to fill in the weave on fiberglass cloth
Most I have seen are using 3 thin coats with light sanding in between
if your trying to fill in the porous holes in the foam it's best to fill those with lightwieght wall spackle....apply liberally (I use my bare fingers working it into the foam) let dry, sand smooth then use the poly...will give a nice smooth finish...use silkspan or 3/4 oz fiberglass cloth for the ultimate in strength and durability
hope this helps

[J Morgan]

Maz
I have heard most people are using the baby powder mix to fill in the weave on fiberglass cloth
Most I have seen are using 3 thin coats with light sanding in between
if your trying to fill in the porous holes in the foam it's best to fill those with lightwieght wall spackle....apply liberally (I use my bare fingers working it into the foam) let dry, sand smooth then use the poly...will give a nice smooth finish...use silkspan or 3/4 oz fiberglass cloth for the ultimate in strength and durability
hope this helps

That is good advice. The spackle sequence should not be left out. It also helps seal the bare foam cells that were opened up during sanding. Spackling keeps them from soaking up poly= more weight. After sanding the spackle you can use the bp/poly mix right away. If you start with a decent surface, usually two coats will do it. I always dry sand the first coat and wet sand the final coat for a very good surface for paint. Good luck.

J

[Maz]

Thanks guys. I`ve glassed alot of planes. I`ll probably do the spackle on the whole plane, then bp/poly two coats. Then I think I`ll glass the bottom with one coat of straight poly just because it`s going to be a belly lander.

Dave

[sgtdirt]

i never thought of using poly with powder. nice tip, dave.