Warped Fins

[coopwyo]

Does anyone know how to take the warp out of a set of fins? When I glued the fins together for my Big Red Max, I put them on a flat surface, assembled them, and then put weight on the top to keep them flat. After the glue dried, I took the weight off and the fins curled up. I tried wetting them with water and then ironing them, but that did not take the warp out. Any help would be appreciated. Thanks!

 

[kuririn]

I had a different set of warped fins.
I used steam from a tea kettle on the concave side to straighten the fins. Then placed under a heavy book to dry completely.
Before:


After:


After straightening and drying I would glue the fins onto the airframe immediately, before it has a chance to re-warp.
The glued root chord will prevent the fin from warping again.
Worked for me.
Good luck!

 

[Back_at_it]

Lay the fins on a flat surface with the bow up. Spray the fins until they are pretty wet with hot water. Put wax paper over the fins and put something dead flat and heavy on them.

Come back in a couple of days.

 

[BABAR]

. Put wax paper over the fins and put something dead flat and heavy on them.

Come back in a couple of days.

I tried it, they came out pretty flat. but I can’t get the smell of flounder out of the fins now.

 

[Rob Campbell]

I tried it, they came out pretty flat. but I can’t get the smell of flounder out of the fins now.

Paint it with a silver scales paint scheme and call it Fish Max.

 

[kuririn]

Paint it with a silver scales paint scheme and call it Fish Max.

Or Der Big Red Herring.

 

[Rob Campbell]

Or Der Big Red Herring.

And cut down the mightiest tree in the forest with it.

 

[Back_at_it]

I tried it, they came out pretty flat. but I can’t get the smell of flounder out of the fins now.

Primer and paint will kill the smell.

 

[David Schwantz]

Use windex. the ammonia will help to undo the warp.

 

[kuririn]

I tried it, they came out pretty flat. but I can’t get the smell of flounder out of the fins now.

Go ahead and send it up, just for the halibut.

 

[jqavins]

The two classic treatments for wood bending are a steam box and ammonia. Steam boxes are used for things like bending the ribs of big wooden ships, and I've seen broomsticks literally tied into knots using really high concentration ammonia. Hot water and Windex are pale shadows of what these things can do, but have often been enough for our purposes. If hot water and Windex are not doing the trick here, try putting the fins in a steamer on the stove top for - I'm pulling a number out of my backside - 15 minutes before setting them to dry under weights. Or wet them down with the full strength stinky ammonia from the cleaning supplies. (If you're thinking of doing both by using the ammonia in the steamer pot, then by all that's holy do it outside.) If even those don't get'm flat, I see three options.

• Upgrade to a better steam box;
• Upgrade to concentrated ammonia, which is way beyond the cleaning stuff; or
• (My choice in this spot) cut yourself a new set of fins.

 

[BABAR]

• Upgrade to a better steam box;
• Upgrade to concentrated ammonia, which is way beyond the cleaning stuff; or
• (My choice in this spot) cut yourself a new set of fins.

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