Fixing wrinkled cardstock on a fin

[Bill S]

I was "papering" the fins on my latest rocket because I messed up with the grain orientation. While I have been trying to make sure that all the excess glue is squeezed out before putting some heavy books on the fin to dry, I found this:



I tried ironing the area to no avail, and I'm reluctant to try anything more aggressive like steam, etc, without asking here first. Its Elmers carpenters glue. Sanding is going to make even more of a mess, I suspect. Ideas as to how to fix?

 

[rocketgeek101]

I'd try soaking the area with super-thin CA to give it a hard finish and then sanding smooth.

 

[neil_w]

Probably not the answer you're looking for but I would just leave it, unless you're prepared to make a replacement fin if it gets messed up.

If you really want to try it, then the CA soak suggested above is probably the best thing to try. After sanding down the bump you might need to apply CA again and sand smooth; unclear how deep a soak you'll get when the paper has a fair amount of glue absorbed.

 

[Hobie1dog]

I would be afraid of sanding on tha,t as where the ca stops, rubbing the sandpaper across the paper would end up shredding it into fine cheese

 

[tsmith1315]

With a sharp (new) razor blade, I'd slice down the middle of the wrinkle.
Peel back both sides of the paper, then lay one side on top of the other. They should overlap a tiny bit.
Slice down the middle of the overlap and remove the slivers of excess paper. The sharpest possible blade makes a difference in this step.
The two sides should meet flat or nearly meet, and proceed with CA treatment and filling the seam.

 

[Bill S]

tsmith, it isn't excess paper in there, but excess glue that I somehow missed when I was smoothing the cardstock down.

"Probably not the answer you're looking for but I would just leave it, unless you're prepared to make a replacement fin if it gets messed up."
Not feasible since the fins are through the wall fins glued to the motor mount.

 

[bjphoenix]

If there is excess glue under the paper it will be difficult to get out of there. You can shave off the part of the paper that sticks up, put some wood filler on it and sand off.

I have papered fins on the past 10 or so of my builds. A small percentage of these get little wrinkle spots on the fins. I put wood filler on the wrinkles and then sand smooth. Sanding the paper can cause fuzzies. I put a couple of coats of spray primer on the fins, sanding after each coat, and this takes care of the fuzzies.

 

[Bill S]

Thanks guys.

 

[KenECoyote]

Careful use of Dremel with sanding drum (small, light "slices" like a deli slicer ), then CA brushed on and super light sanding.

Just like building rockets in general, add more time and care depending on how nice you want it.

 

[KenECoyote]

Oh, also the paper fuzziness is a lot less if you prime the area first before you try the repair.