Estes Boosted Bertha #001946 Build, Part 2, Fin Prep

I was curious about the fins, if they were the same as the regular Big Bertha.
I went to Jim Z's and printed up the Big Bertha fin template.

Setting the kit fin on the older template - it's pretty darn close!

Lots of balsa to fill!
On the left are the standard Bertha fins from the upper stage.
On the right are the larger, TTW tabbed booster fins.

At club launches I see fins that didn't have the laser burnt edges cleaned up. Glue sticks better to clean surfaces, not burnt ash.

Take a few minutes and sand the edges square using a sanding block. Both pictures show the fins sanded about halfway. It shows the "wedge" cut from the laser.