Canopy Skirt Sealing

06 Apr 2004 Canopy Skirt Sealing

From Scott B:

For those of you who are building and want a perfect canopy skirt fit, don’t forget, liquid shim, which is epoxy with flox to a thick paste. Mask off the fuse apply the epoxy to the mating surface of the skirt, close the canopy and come back tomorrow. Perfect fit every time! My canopy fits perfectly all the time from cold to hot meaning 32 thru 90 deg F. In my case the only down side is that the skirt is a little thick where it mates with the fuse but not too noticeable. A benefit of that is the skirt does not pull away from the fuse in flight.

From: Dane Patterson
To: rv8list@yahoogroups.com
Sent: Wednesday, April 07, 2004 6:10 AM
Subject: Re: [rv8list] What is and Where can I find Liquid Shim??

I think the “Liquid Shim” that Scott is talking about is exactly as you
have described it: Epoxy mixed with Flox to form a paste. I recommend
that you start looking in the Aircraft Spruce catalog. I like West
Systems Epoxy and I buy the Fast hardener. Spend the money for the
proportioner pumps and it is Marine proof (even a Marine can’t mess it
up). Like Scott says, mix the epoxy and then add flox till it’s a thick
paste and then…

I have heard the thickened epoxy mixture called “Liquid Shim” and have
used it with very good results when assembling parts of my airplane.
Here is the secret to having a great looking airplane: When you are
ready to rivet a skin onto the ribs, slather the mating surface with
“Liquid Shim” and cleko it in place. Wait overnight for the epoxy to
cure and then come back the next morning and drive your rivets. The
“Liquid Shim” will fill any voids between the rib and the skin and the
skin won’t pucker or shift as you rivet it in place. For this
application I would not recommend Flox as a filler, use Milled Fiber or
Microbaloons instead. You want it to ooze out, where it’s not needed.
Liquid shim made with Flox will not flow out as easily, which is why, I
suppose, it would work great for forming the mating surface of a canopy
skirt.

Now that you have some background information, the term “Liquid Shim”
makes more sense. I hope I haven’t given away anyone’s secrets. Good
luck with your canopy skirt.

Dane