Applying Heat Shrink Coverings

[Bill Burton]

Is there a method to apply these shrink type coverings like Ultracote or Monokote without the pull it creates from bowing or twisting the wing as the heat is applied?

Thank you
Bill

[Tim Wescott]

It shouldn't bow the wing unless the wing structure is really too wimpy.

On a wing like a Ringmaster, or just about anything else where the structure doesn't have much torsional rigidity, it may twist -- but it's really easy to untwist it.  Just put it on as evenly as you can (to prevent the initial twist), then if it's twisted tweak the wing in the opposite direction and re-shrink.

[David_Stack]

I've had the best luck covering both top and bottom before doing any final shrinking of the covering, and then working my way spanwise from center to the tip, doing a bay at a time top and bottom before moving on to the next bay.

Something you may want to try...

r/
Dave

[Bill Burton]

Thank you for the help.

BB

[john e. holliday]

As stated earlier, put the covering on as tight as you can.  Cover all surfaces and get the heat gun and start shrinking.   Once you have the covering drum tight, sight from the rear and see if you have warps.  If so use the heat gun while twisting the warp the right direction.   If it is a bowed trailing edge or leading edge you may have to extra hands to help.   

[Phil Krankowski]

Most of these coverings have a gap between the glue activation temperature, and the shrinking temperature.  The gap is quite small on some of the coverings though.  Try using a lower temperature setting.

Try calibrating a point on your iron to boiling water by sprinkling water on the iron face.  When the iron clicks off the water should be boiling, and it should stop boiling about when the iron clicks on.  Mark the dial with a sharpie or paint.  Now when you read the instructions for the film there is a reference temperature on your iron to get started. (212F, 100C)

This works well with red and yellow very well, less so with blue.  White and black not so much...  There is a color change at the glue activation temperature with all the films I have used.  The change is slight, and is usually a darkening of of color. 

Lots of good advice for wrapping the wings already in this thread.  Get it even and tight before shrinking.  The less shrinking done the better.

Phil