The original windscreen was from the front pit of a PT-19. I think the fuselage it came from once sat near the road going into Owosso, Michigan. OK, that was over 50 years ago.
You can see it was very low, sort of racy looking. In fact it was so low Dad hit it pretty hard with his face one day. Yes, that's Pete Bowers at Rockford 1966.
The frame got modified. The base is still the original PT-19 windscreen as are the clamp strips which hold the glass in the frame. The 2 front corner pieces were cut off and longer ones made to raise the top of the frame.
Over time, the wear of people pulling themselves out by grabbing the top corners of the frame caused the corners to crack badly. I decided to repair the windscreen before making the new cowl panel under it.
I removed the glass and the corner pieces. I used the corner pieces as patterns for new pieces, which I made from 0.025" 2024-T3 aluminum.
The problem was how to put a nice bend on the corner where the screws go for the glass retainers. I decided to press the corner into some stiff felt. I used 2 pieces of 1/4" thick spruce, 1" apart, stuck to a piece of 2" Gorilla Tape to form the die. The felt was laid on top of the strips.
A piece of 3/8" wide aluminum was used to press the piece into the die. It worked but I couldn't get the angle I needed.
I moved the wood strips to a 3/4" gap and used a 1/16" strip of rubber, in place of the felt, to protect the aluminum.
That worked to get the needed angle.
The corners were formed to fit just as the originals so they could be riveted to the original holes from the 1967 modifications.
To solve the corner cracking problem I made some corner stiffeners from 0.035" mild steel scraps and welded the corners closed.
I started with a card stock pattern to work out the shape and bend lines.
Each corner is slightly different so patterns and blanks were made to fit each.
I found after my first failed attempt that I needed to bend the front corner angle first and then the other bends to fit.
I left extra metal along the back to trim after bending.
Each bend was marked and then formed using sheet metal pliers.
With the top screw holes added and the back edges trimmed the parts were ready for welding.
The corners were welded, the pieces sand blasted, and painted to match the frame.
I like the industrial look of the rivets and screws left unpainted.
The new Plexiglas panels don't need sealing but if you've ever found yourself flying in light rain it can be real annoying to have water leaking in on you. The airflow around the windscreen is such that the rain goes over your head and back onto the fuselage. I used the same seal material I used for the Cessna 140 skylight windows.
I put a strip along the edge of the frame and pressed the glass into it for a tight seal, it's very sticky and soft.
I trimmed any excess from the outside of the glass with a plastic razor blade scraper.
The windscreen ready for the new cowl panel.
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