Below, the basswood fins I cut for the Centuri Scram Jet.
Notice the fin grain in the upper fin unit.
This was after CWF filler, primer / filler and sanding after the first white undercoat.
The grain is still there!
I've noticed this lately with the balsa replacement - Tung wood - in the Estes kits.
I like that the Tung wood is harder and stronger than balsa.
But - the grain pores are much harder to fill. It seems when the filler coats are sanded, more pores open up!
The gloss white Rusto 2X paint is dry on the basswood fins. The paint on the Tung wood is still sticky. Both were sprayed at the same time!
I know there isn't grain pores on basswood. I wanted to show these together for comparison.
The Tung wood should look like the basswood after all the regular filling process done on the supplied kit wood.
Agreed. I put an Estes kit with the tung on the shelf because of frustration for the same reason-the fins never sanded out clean, even with filling, priming and paint. I copy the pattern and use basswood-it's stronger and smoother, with a marginal increase in weight, plus it requires little prep work.
ReplyDeleteOut of curiosity, have you tried papering the Tung Wood, and if so what are the results?
ReplyDeleteI've papered fins for years. It depends on the shape and how the edges are rounded. This design doesn't really lend itself to papering. The fin assembly is a little more complicated than just three flat fins.
ReplyDeleteThere's an old Model Rocket News from the 1970s that suggested using the old PRM (Paper Reinforcement Material) self adhesive paper to cover fins. I've also used tissue liked that is used on balsa airplanes.
I was more curious to see if others were having problems filling the Tung wood now found in Estes kits.