Decided to get moving on this TSB that Vans came up with for strengthening the Roll Bar rear Channel.  They sent

me a small piece of 1/8" aluminum spacer,  4 screws washers and nuts.  I marked the top skin to show where the

Channel was located along with where the spacers front edge would be.  Hope I never ground loop my plane but

if I do lets hope this mod makes a difference.

I drilled the 4 pilot holes in the spacer and used it as a drill guide for the skin.

Since I have already had the rear window installed, I quickly realized that an 1/8" spscer was going to be too thin.

If you installed it and tightened the screws down you would crush the skin below the level of it original position.

So I added another 1/16" piece to make up for the height difference. If I had a piece of 3/16" it would have gone

a little easier since the plexi is right at 3/16' thick at this location.

This shows where I notched the rear window to accommodate the spacers.

I then countersunk the 1/8" spacer.

I obviously installed them with the 1/8" spacer up top and used the screws to dimple the top skin.

Here's is the cool Aluminum Button Head Screws I decided to go with as opposed to countersinking and dimpling

my Canopy Plexi-glass and associated parts.  I am using 6-32 sizing from 3/8" to 5/8".

I got them from Fastener-Express . com    

Check out the low profile locking nut.  If you use Aluminum Nuts on Aluminum Screws I would recommend using

Boelube or equivalent anti-seize.