Final Fabric Shrink and Primer

It's looking good! As the rudder is almost ready for paint I am pleasantly surprised with the results at this point.

First thing before the final heat shrink of the fabric, I picked up a basic full-size iron from Target. The small hobby iron I had worked great for small lines, curves, and tape, but it would loose heat quickly and was very lightweight. This one worked great, held heat well, and had a bit of weight to let the iron do the work when shrinking. I used my infrared thermometer to get exact dial points for 250, 300, and 350 degrees (the white paint marks on the dial). The iron worked well and held its temperature within +-4 degrees. I looked a while for an iron without auto shutoff, but it wasn't a problem with this one. It had a red light that would flash when in auto shutoff mode, so you will see it and know the iron needs to heat up again. Plus, it only took about 60 seconds from cold to full heat.

I started with the iron at 250, working the tapes and seams in an alternating pattern to avoid distortion while the fabric shrinks. Then, I worked the open fabric in the same manner, letting the weight of the iron do the work as it slowly slid along. The results were positive with wrinkles shrinking up, glue bonding stronger, and the fabric tightening up. After a cooling period, I repeated the process with the iron at 300, then after another cooling period did it all again for the final shrink at 350. The tightness of the finished fabric turned out very strong.

Finally time for paint! The primer process using Stewart Systems EkoFill uses three coats applied in a certain manner as a primer and UV blocker. The first coat and the second coat are applied in opposing directions. I put the first coat on with a foam brush from front to back, taking care to use even strokes and getting a good full coverage.