Saturday, August 18, 2018

Windshield Installed


 I went to install the piece of cowling with the windshield and realized it wouldn't go on with the center section installed.  I thought I could split the bottom of the cowl where the rear of the cabane strut attaches so it could get around the strut.  That didn't work either.  I finally realized I needed to remove the rear strut bolt and pivot the strut up around the front bolt. That worked fine and I probably could have done it with the center section still bolted to the struts.  Oh well, we got there.

 Once I had it on I realized I hadn't installed the little tabs to hold the top of the instrument panel from tipping forward with the weight of the instruments, so back off again.

I decided to use some old scraps of 1/8" x 1" aluminum angle.  I thought I would just tap a screw hole in it rather than install a nut plate.  In the end I used a nut plate on each.

 The instrument panel is tipped slightly from perpendicular to the cowl so I had to bend the angle about 3/32" to get a nice fit.

 To get the holes in the brackets to align with the holes in the Instrument panel I riveted the brackets to the cowl and re-installed it. 

I then drew the hole locations on the panel so they would be close to the center of the brackets and drilled through the panel and the brackets.

With the cowl back off I could then install nut plates on the back of the brackets.

 The cowl and center section are finally back on, again, with the panel screwed to the brackets.


 In this process I discovered another small problem.  My clever bracket for the temporary vacuum gauge was bolted to the 2 bolts on the outside of the cowl not the 2 on the inside.  I'll need to make another bracket.
 I also found that some of the screw holes along the top of the firewall don't align with the cowl holes.  I used a circle template to draw where the holes should be.  Then I took out all the screws except the aft screw on each side of the cowl. This allowed me to tip the cowl up just enough to re-punch the holes with the Whitney punch.  I used a punch with the nib ground off and aligned the punch with my drawn marks.  It worked.
 While I had it up I put a bead of high temp. RTV along the cowl with strips of waxed paper on top.  The waxed paper is to keep the RTV from gluing the cowl to the firewall while still forming a nice gasket to keep oil and fumes out of the cockpit.

This time I think the cowl is on to stay.

 I used Contact Cement to glue some anti-chafing strips to the edges of the cowl piece above the engine.  This piece isn't intended to move, but all the engine vibration and air loads do cause it to wiggle slightly.  The 2 access doors are just held shut by belts so they wiggle quite a bit.

Fortunately the holes in this cowl piece all match the firewall and it covers the mis-located holes in the other piece.  We're getting there.

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