As is all too common on vintage boats, the windshield on my 1959 Lake N Sea was beyond salvage-
I looked for a replacement, without luck. So, I decided that I would have to make one.
The old one was acrylic- 1/4" thick. Making an acrylic windshield would require heat bending, and since I don't have access to an oven large enough to heat a part that large, and trying to do it with a heat gun would be tough. So, After doing some research, I decided to try to use Polycarbonate instead. Polycarbonate is stronger, and more flexible. With the extra strength, a thinner sheet can be used, which will conform to the curves better.
But first, I had to make a new frame. The frame is aluminum, and happens to be EXACTLY the same as a profile that you can get at almost any home improvement store. It is a "u" channel designed to put over the edge of a 1/4" sheet of plywood.
To bend it properly without it distorting and crushing, it has to be annealed first to soften it. Annealing requires heating it close to it's melting temperature, then allowing it to cool. I use a propane torch to anneal-
Keep the torch moving- It's tough to tell when aluminum is hot enough, it won't start glowing like steel does, it'll just melt. To tell if it's hot enough yet, I run a piece of scrap wood across it-
The wood should burn instantly, and leave a nice trail of carbon behind. This isn't an exact science- But it gives you a pretty good idea if the metal is hot enough. Once it is, you let it cool slowly. You don't need to anneal all the aluminum, only the area that you intend to bend.
I made a wooden buck that matches the curve on the old windshield frame, and will be using that to bend the new piece-
In order to keep the channel from collapsing when it is bend, I filled it with cardboard strips-
Once the bend is made, the same bend is made in the other side, and the cardboard removed. The result is a new frame that matches the curve on the old one exactly-
After a quick polish, the new frame is ready to go.
Now for some Polycarbonate...
I looked for a replacement, without luck. So, I decided that I would have to make one.
The old one was acrylic- 1/4" thick. Making an acrylic windshield would require heat bending, and since I don't have access to an oven large enough to heat a part that large, and trying to do it with a heat gun would be tough. So, After doing some research, I decided to try to use Polycarbonate instead. Polycarbonate is stronger, and more flexible. With the extra strength, a thinner sheet can be used, which will conform to the curves better.
But first, I had to make a new frame. The frame is aluminum, and happens to be EXACTLY the same as a profile that you can get at almost any home improvement store. It is a "u" channel designed to put over the edge of a 1/4" sheet of plywood.
To bend it properly without it distorting and crushing, it has to be annealed first to soften it. Annealing requires heating it close to it's melting temperature, then allowing it to cool. I use a propane torch to anneal-
Keep the torch moving- It's tough to tell when aluminum is hot enough, it won't start glowing like steel does, it'll just melt. To tell if it's hot enough yet, I run a piece of scrap wood across it-
The wood should burn instantly, and leave a nice trail of carbon behind. This isn't an exact science- But it gives you a pretty good idea if the metal is hot enough. Once it is, you let it cool slowly. You don't need to anneal all the aluminum, only the area that you intend to bend.
I made a wooden buck that matches the curve on the old windshield frame, and will be using that to bend the new piece-
In order to keep the channel from collapsing when it is bend, I filled it with cardboard strips-
Once the bend is made, the same bend is made in the other side, and the cardboard removed. The result is a new frame that matches the curve on the old one exactly-
After a quick polish, the new frame is ready to go.
Now for some Polycarbonate...
