Fixed Window Replacement

Project_Mayhem · 2026-01-09T08:03:07-0800

Any plastic supply hour or fabricator can sell you the material. TAP Plastics is often recommended. Have you cut this material before? It chips at the edge very easily if not done correctly.

There's a lot of debate between acrylic and polycarbonate. Acrylic wins these debates more often.

dlochner · 2026-01-09T08:03:08-0800

I believe the SBO store sells precut windows. Give them a call.

Ralph Johnstone · 2026-01-09T11:04:11-0800

Project_Mayhem said:
It chips at the edge very easily if not done correctly.

If you are familiar with routers, a profile bit will give you flawless edges
+/- 0.001" at high speed and light pressure.

If you are serious about doing this, PM me.

Project_Mayhem · 2026-01-09T11:12:41-0800

Ralph Johnstone said:
If you are familiar with routers, a profile bit will give you flawless edges
+/- 0.001" at high speed and light pressure.

If you are serious about doing this, PM me.

It absolutely will. I've gotten perfect cuts going slowly with a fine toothed table saw blade as well. There's more advanced techniques that involve heat to get a crystal clear edge. I do not recall the equipment needed for it however.

Next time I need a good clean edge, I'd probably cut with whatever saw I please and finish it with a router. It would take a few test strips to get everything setup correctly.

If the OP tapes the old window to new material to use as a template on a table saw, what complications can be expected?

RussC · 2026-01-09T11:51:33-0800

SV Temenos said:
I want to replace the frameless fixed windows on my Hunter 39. Does anyone know where to source the material? I'm assuming it is acrylic but if anyone knows exactly please let me know. Also if anyone knows the percent of tint. I can cut the raw material so that is not a problem. I'm having a problem finding where to buy it so any advice will be greatly appreciated.

I got my plexiglass here Amazon.com and am very happy with it. tint is just right for privacy wile not blocking vision and it works easily. cut with bandsaw and routed the edge. drilling screw holes was no issue either. different sizes available to fit your needs.

dLj · 2026-01-09T13:52:51-0800

I usually buy from Mcmaster-Carr. They tend to be a bit pricey, but they specify what you are getting. The Amazon link above does not give me the information that I would like to have on what the actual product is. If you wish to go with acrylic, then you want cast acrylic. We can get into the debate of acrylic vs polycarbonate if you'd like (guessing not)...

Here's a link to Mcmaster that is cast acrylic - also has the colors and tints...

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

dj

thinwater · 2026-01-09T14:06:02-0800

Don't assume that windows were cut to the perfectly correct size the first time. Look closely. When I replaced mine it was clear one was not correctly fitted at the factory, perhaps contributing to leaks 30 years later. There wasn't enough room for sealant movement on one side. I can't complain, but I did trim the window a tiny bit differently when replacing it.

Ralph Johnstone · 2026-01-09T17:25:14-0800

Project_Mayhem said:
If the OP tapes the old window to new material to use as a template on a table saw, what complications can be expected?

I don't know what would happen using the original piece as a template on a table saw. I would live in holy fear of the acrylic dust getting between the two pieces and raising hell. I just mark out the new acrylic with a felt pen and then plough it through the table saw with the carbide blade. It's only a crude cut with edge chips and other flaws. Cut it 1/4"+ bigger than the original acrylic. Do the +/- touchy feely work with the profile router bit.

When using the profile router bit, I always hold the original and new piece of acrylic together with double sided tape.

dLj · 2026-01-09T17:48:51-0800

I use my jig saw with T101A blades. They cut acrylic and polycarbonate like butter and leave a really nice clean edge. You do have to be careful cutting curves if the radius is small.

dj

Project_Mayhem · 2026-01-09T18:15:44-0800

Oh yeah, try to avoid screw holes if possible. Very easy to overtighten and create cracks down the line. BoatWorksToday has a video on using VHB tape to hold it in place while the sealant cures

Ralph Johnstone said:
When using the profile router bit, I always hold the original and new piece of acrylic together with double sided tape.

This is exactly what I meant

dlochner · 2026-01-09T19:21:34-0800

Project_Mayhem said:
Oh yeah, try to avoid screw holes if possible. Very easy to overtighten and create cracks down the line. BoatWorksToday has a video on using VHB tape to hold it in place while the sealant cures

This is exactly what I meant

And if for some reason it is necessary to use screws or through bolts, drill oversized holes. Acrylic and steel have different rates of thermal expansion. If the hole is snug the acrylic will crack when the screw expands.

RussC · 2026-01-09T21:12:06-0800

dlochner said:
And if for some reason it is necessary to use screws or through bolts, drill oversized holes. Acrylic and steel have different rates of thermal expansion. If the hole is snug the acrylic will crack when the screw expands.

don't ya just hate it when that happens. :beer: