Best tool for hand cutting acrylic or polycarbonate boat windows

[C08]

Hi
Is an exakt saw any better for cutting windows out of sheet than say a jigsaw or is there a better tool such as a reciprocating saw. What about temperature build up and melting? plan to cut to shape and clean up edges with a planer-is that the best way?

 

[symondo]

Perspex is a nightmare to cut.

I always found the best way was to sandwich it between 2 pieces of wood and cut away. This removed any vibration which causes is to shatter.

 

[prv]

I made a new set of washboards out of polycarbonate. Cut fine with a jigsaw, and I used a router to make the rebate between the two halves.

Pete

 

[VicS]

Hi
Is an exakt saw any better for cutting windows out of sheet than say a jigsaw or is there a better tool such as a reciprocating saw. What about temperature build up and melting? plan to cut to shape and clean up edges with a planer-is that the best way?

Band saw works well for small items.

When I bought new boat windows I had them cut to size/shape by the supplier .

I also need two of them drape moulded to match the curvature of the cabins sides. This was done using the old windows as "moulds"

 

[Mudisox]

I am doing the same this winter and tested a variety of methods, but have come down to the conclusion that I'll pay the supplier to laser cut them, and have them routed/milled at the edges. Jigsawing whatever the size of cutting edge tended to just heat and melt the polycarbonate, and my windows are bigger than I would want to do myself. I will however drill the holes for teh bolts to match the existing ones in the side of the cabin sides.

 

[Lakesailor]

I've used one of those diamond-encrusted wires for ceramics for cutting odd shapes in acrylic sheet. You can get them to fit hacksaw frames.

 

[penfold]

Jigsaw is best if you have one with adjustable speed; a slow speed, use a fine wood blade and if your jigsaw is spiffy and has adjustable backswing, experiment with that to find the best setting.

 

[nigelmercier]

Jigsaw is best if you have one with adjustable speed; a slow speed, use a fine wood blade and if your jigsaw is spiffy and has adjustable backswing, experiment with that to find the best setting.

You ideally need a specific blade: T101B

I suggest cutting oversize by a couple of mm and using a belt sander to finish.

 

[Tranona]

Agree with having it cut professionally with a laser cutter - and drilled if necessary. Much better finish and far less work than trying to do it yourself, although the fine jigsaw and router is the next best alternative. The additional cost of having it cut is minimal compared with the cost of the material.

 

[dylanwinter]

This is a vid of cutting it with a jig saw

 

[lustyd]

If using a jigsaw it's not a bad idea to set up a fence to guide the saw in a straight line. Jigsaws can get very wiggly in the hands of someone who doesn't practice much

 

[vyv_cox]

I found that a toothed jigsaw blade melts Perspex almost as much as it cuts it but a diamond blade seems to work quite well.

 

[trapezeartist]

My first experience on cutting "perspex" was making a set of windows for a lightweight Mini. We had gone nearly all the way around the back window with a bandsaw before realising that the two sides of the cut were happily welding themselves back together immediately behind the saw blade.

 

[Lakesailor]

Isn't that annoying?

 

[PlankWalker]

I cut acrylic using a standard jig-saw on slowish speed and drip water in front of the blade using a squeezy bottle, I'm very careful of course and a pair of rubber gloves might be handy.

Plank

 

[geem]

I have just made new windows for our boat. A total of 16 windows in 10mm for fixed and 13mm for opening type. I purchased a new scroll saw for £100 that I used for all the corners. It was slow but accurate. I used a belt sander to smooth those corners where necessary. The scroll saw doesn't melt the perspex. An electric plane was useful to achieve straight edges and remove material quickly. Keep the perspex at room temperature or it will crack. This is what happened cutting out a new washboard in the garage. The perspex had been in there all night and was cool.
I got the supplier to cut out the windows as a rectangle similar to the size of my windows so I didn't have to handle large sheet sizes. This way they easily fitted on the scroll saw. The scroll saw is now surplus to requirements so if anybody wants to purchase for this job I am open to offers.

 

[pampas]

special blades for jig saws are available, look something like a bread knife. Hard to find, watch your fingers when fitting, run at slow speed.

 

[ghostlymoron]

I cut perspex windows for my L17 just using a jigsaw with a medium blade. I was not aware of the potential melting problems and they didn't occur for me maybe I was lucky.

 

[Ruffles]

I use a hand saw and and long flat file to clean the edge. It's actually very quick.

For exposed edges very fine wet and dry produces a surface that is pretty well transparent.

 

[C08]

"Keep the perspex at room temperature or it will crack. This is what happened cutting out a new washboard in the garage. The perspex had been in there all night and was cool."

Thanks for advice chaps-the temperature tip above is good -it would have made me weep to crack a 62"x26" wheelhouse front window,apart from the financial pain!