There isn't a good way to fill this much balsa after the fins are glued to the body.
The 3/32" stock really warped after brushing on CWF to one side.
Most of this went away when the filler was applied to other side.
To be sure the warp goes away, the fins were set in a fold of waxed paper and in a heavy book for drying.
After the fins sat overnight, the wax paper was peeled away. The warps were gone.
The "pads" were also filled before gluing to the wing ends.
It's hard to see in the picture, but I used a toothpick to clear the slots of excess CWF.
Any water-based filler on balsa wood is just asking for a warp. This is not a defect of the kit, or the balsa in it, but with the material used to fill it and how much water is in it. Water and moisture will always warp wood. Which is why I am still old school - lacquer-based sanding sealer like Midwest makes, or if using CWF, thinning it as little as possible. In some situations, thin ca works pretty well.
ReplyDeleteThe balsa in this Quest kit warped more than normal. Years ago (when I used sanding sealer) I'd see some wrap, but not like this! Even with sanding sealer there is shrinkage and unless both sides are painted at the same time you'll see some pulling.
ReplyDeleteThese days I prefer the CWF. One coat and it's filled as opposed to four coats of sanding sealer.
You won't see this much warp in the new Estes kit "balsa". I'm still convinced the new Estes kit balsa is actually tung wood. It's almost as light and much harder than balsa.