Shrink Wrapping the Rudders

I've successfully covered the rudders with shrink wrap. They look pretty good.

Two shrink wrapped rudders.

I've still got quite a bit to learn about how to effectively use the shrink wrap gun. But I only had to redo one of the rudders. 

The first one I took longer to do. 

You'll note that I spent more time at a distance and definitely burned some holes. I also tried to adhere the edge using heat bonding. However it was problematic as I was pushing against the open part of the frame, thus couldn't get much pressure between the pieces I was squeezing. 

Results of first attempt to shrink wrap a rudder

A close up of the burn hole, and some of the edge attachment

Where the bolt ends pierced the shrink wrap

At the other end, 2/3 bolts burned through. 

I tried again on the 2nd rudder. This time I clipped some holes for the bolts first and ran tape over the ends. I also used the shrink wrap tape down the trailing edge and over the ends with the hopes of getting a smoother surface once shrunk. 

Taped edges visible with bolts cut through early.

 Here's how it went:

The results were notably better. With a few caveats. Clearly the tape worked better, but there's still some curling up at the edges of the tape.

Overheating at the ends, but bolts are much better. 

 And I clearly discovered that applying the tape down with full pressure is important. I missed a few inches that were not pressed down well, and consequently the stretching pulled the adhesive apart before it could fuse. (I probably also heated the front edge first too.

A tear where the tape was not adhered well enough.

But I was able to patch it over relatively easily with another strip of tape, and a quick heating by the heat gun.

I patched the tear with another layer of tape and tensioned it again to look like this afterwards.

 I cut the shrink wrap off of the first rudder and tried again. The biggest difference I note is that I'm more confident. I move more quickly at closer distances. And the other thing is that the wrap shrinks when cooling, not when hot. When it's hot it's actually softer. So when applying heat, you don't apply heat until it's taught. You apply heat quickly and then move on. After it cools come back and check on it, and if it's not tight enough re apply heat. Continuing to apply heat to an area basicaly melts it and or burns it.

Here's my 3rd attempt.

The results worked out well. I used the above quick heating and trust that it will shrink later. As well as I trimmed more of the excess film away. And I taped at the trailing edge, and made sure to apply the tape firmly and press the edges down hard against the frame underneath instead of taping where there was an air gap.

3rd attempt size A

3rd attempt side B