Making a New Plexiglass Windshield For Boat

[ERock82]

I am going to recreate the busted up windshield that I took off of my Bayliner. It is 1/4" plexiglass and I plan on buying a sheet and using the old one as a template. I found someone that will cut it for me for a good price.

What I need to know is if it is cold formed or heat formed. Basically, was this made with a mold or heated to shape the curved sides or does the piece go on flat and it naturally curves when bolted on?

I am attaching a couple pics I found of the same windshield on other boats. It is a very little curve which leads me to believe there would be no heating involved. If so, I should be able to remake this for less than $100 if I cut myself or about $130 if I pay to have cut out. If I have to have it heated and formed it will probably be double.

The old one easily flattens out if stepped on while laying on the floor but retains it's slightly curved shape on the ends when released.

 

[JoshOnt]

Have a search on the forums, there are a few threads about making windshields. I believe it was WOG that had a great one, it is a fairly simple process to do and depending on the method you might need a heat gun.

 

[NYBo]

The mounting points aren't too easy to see well in the pix, but they look pretty stout. If so, cut the plexiglass, start attaching it at one end, and see how it goes. Use a heat gun sparingly to assist with the bending as you go.

 

[fhhuber]

That will have been heat pressed to the curve.

Without having it heat formed the plexi will be constantly under stress and will break at the bolt holes. It may last a couple of years or less than a week, mainly depending on how well you do at drilling the bolt holes and then sanding/buffing them to ensure there are ZERO cracks.

Drilling the holes can be "interresting" It will all seem fine until just as the drill comes out the other side then it can shatter the plexi. You'll do this EVERY time with a normal high speed drill bit.
Its better to grind through with an abrasive... very slowly (or the plexi softens and clogs up the bit then you will have the bit glue itself to the plexi and shatter it)... if you don't have the correct plexi bit.

Melting through with a soldering iron is another option.

Once you have the hole through you sand and polish it so there are no sharp corners and it is buffed to where you can't see scratches.

***************

Heat gun bending isn't recommended. It won't be even. It will be very noticeable.

Best is to make a form out of wood, sanded and VERY smooth. Then put it under heat lamps and let it sag from the weight of the plexi.
Of course the labor is a bit extreme for a one-off piece.

***********

I made plexi display cases for a museum.

 

[airshot]

If I might suggest....do not use plexiglass as it will crack and develop stress fractures. Today we use polycarbonate sheeting known by the popular trademark of Lexan. It is unbreakable!, easy to saw/cut and can easily be bent with out worry of cracking. I just made a polycarbonate windshield for my UTV and cut it with my "rotozip" tool that many of you probably use for cutting drywall holes. Anyone with access to a sheetmetal brake (bender) will find this stuff bends quite easily on the brake without cracking! Yes the lexan material is more expensive......but if you scrap a piece of plexiglass then there you go having to buy another. Most all plastic windshields today are made from polycarbonate, safer, easier to work with, impact resistant and will turn out a far better looking job with less headache.

 

[NYBo]

That will have been heat pressed to the curve.

Without having it heat formed the plexi will be constantly under stress and will break at the bolt holes. It may last a couple of years or less than a week, mainly depending on how well you do at drilling the bolt holes and then sanding/buffing them to ensure there are ZERO cracks.

Drilling the holes can be "interresting" It will all seem fine until just as the drill comes out the other side then it can shatter the plexi. You'll do this EVERY time with a normal high speed drill bit.
Its better to grind through with an abrasive... very slowly (or the plexi softens and clogs up the bit then you will have the bit glue itself to the plexi and shatter it)... if you don't have the correct plexi bit.

Melting through with a soldering iron is another option.

Once you have the hole through you sand and polish it so there are no sharp corners and it is buffed to where you can't see scratches.

***************

Heat gun bending isn't recommended. It won't be even. It will be very noticeable.

Best is to make a form out of wood, sanded and VERY smooth. Then put it under heat lamps and let it sag from the weight of the plexi.
Of course the labor is a bit extreme for a one-off piece.

***********

I made plexi display cases for a museum.

Great points. Heat lamps make a lot of sense.