Okay - everything was going well up until now.
I was only happy with the way one fin out of four turned out.
I was careful not to use much glue to attach the internal balsa ribs, but I still had distortion. I wasn't too excited about all the edge and joint filling I was faced with. So, I took the easy way out.
No handy balsa was thick enough to cut out replacements, so I laminated two pieces of 3/32" balsa. I simply sanded them to a wedge shape - DONE!
The side surfaces were smoother with no distortion or "pulls" from the glue. I don't know why Estes went with a built up fin on the Little Joe kit. I can understand using built up fins on the Saturn 1B, but on this kit, I found it easier to sand the wedge shape from sheet balsa.
On the left is a "test" fin made from balsa above the one built up fin that turned out well. To the right are the four fins I'll use on the model.
TIP: Here's a tool I find helpful.
I'm holding a Little Joe II fin in a Machinist Square.
The square is at a perfect 90 degree angle. I'll lightly sand the fin sides until the root and trailing edges match the 90 degree angle of the square.
On a four fin model this can help the finished rocket stand on all the fins without wobbling. That is, if the fins are all glued on the body tube equally.
On a three fin model, it doesn't matter. It'll stand on all three trailing edges no matter how badly aligned the fins are.
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