Best way to cut Plexi-glass

Divecoz · Post by **Divecoz** » Sun Nov 18, 2007 7:13 am

So how have you had success cutting plexi-glass? I am looking to make a tinted cabin door.

bastonjock · Post by **bastonjock** » Sun Nov 18, 2007 7:20 am

you can use either a jig saw or a knife with a heated blade,assuming that it is plastic glass that you are talking about

Divecoz · Post by **Divecoz** » Sun Nov 18, 2007 9:00 am

Yes its the plastic /Glass I am referring to . I have tried with a fine blade and it gums up, adding a lot of work. A coarser blade which cut faster but leaves a rough edge. Both then require sanding and then flame to bring back the clear smooth edge. I must be either doing something wrong or using the wrong blades or I am just expecting too much in the initial cutting.

eric3a · Post by **eric3a** » Sun Nov 18, 2007 9:06 am

Post by **kmclemore** » Sun Nov 18, 2007 9:55 am

If your blade is heating up and causing the plastic to melt and 'gum up' then you're simply going too fast. Take your time, slow down your cut and it will cut fine. As for me, I use a sabre-saw with a medium-tooth flush-cut blade (one where the sides of the blade are ground smooth) when I cut the stuff - makes for a cleaner cut.

For finishing the edges I use a belt-sander with a fine-grit belt, then finish with a buffing wheel.

Highlander · Post by **Highlander** » Sun Nov 18, 2007 10:44 am

For large cuts use a circular saw with a fine cutting blade like used for cutting plywood and install the blade backwards

John

Terry · Post by **Terry** » Sun Nov 18, 2007 10:53 am

Highlander wrote:For large cuts use a circular saw with a fine cutting blade like used for cutting plywood and install the blade backwards

John

Yes,
I did the same thing when I cut a second door except I neglected to install the blade backwards. Still, it workrd pretty good and when I finished cutting it I simply smoothed the edges with a file. You don't see them anyway when the door is in place. Not sure I like the see through door though.

Catigale · Post by **Catigale** » Sun Nov 18, 2007 1:26 pm

I believe you can buy it with a paper backing attached that minimises chipping of the edges... I havent cut it in ages though, I confess. Partly because there is plastic shop next to my favourite breakfast diner 2 minutes from home where cash is king....

Divecoz · Post by **Divecoz** » Sun Nov 18, 2007 4:07 pm

I have been playing with cutting some scrap plexi-glass and I think Kevin is right I was trying to make it go/ allowing it to go, too fast.
I am toying with a lot of projects / fun things to do and desire a little more light at night from the entry hatch. I am toying with the idea of a Oak frame with Plexi center and maybe a screen insert.
I retired at 56 y.o.a. in July and I now finally have most the house project's and honey-do list finished. My wifes aged folks have been moved into a retirement facility and I have much or most of that nightmare behind me.
I am looking for Fun Things To Do. I think want to learn how to wood carve both by hand and with a new 300,000 rpm system I have found and glass etching with a new system that's now available. I have built cabinets in the past but for rental's I owned etc,. Now I want to do it for ME for FUN! I am even again finding a little time to restore our MGB and hope in the end it looks half as good as one of Kevins

Somewhere in there I am going to be making time to actually learn, to really play, the guitar.

KayakDan · Post by **KayakDan** » Mon Nov 19, 2007 8:10 am

I cut a clear plexi companionway door for my M and had the fusing problem also.
Solution is (cutting outdoors) have the Admiral spray a fine mist of water on the underneath of the surface your cutting,cooling the plastic so it will not fuse behind the blade.
Of course you use EXTREME CAUTION to keep the water away from the jig saw as water and electricity don't mix very well.

I would also recommend the saw operator wear gloves as a precaution

Divecoz · Post by **Divecoz** » Mon Nov 19, 2007 8:36 am

My cheap crap saw cuts it for me , better than my Professional model.
My cheapo has a little red screw in the trigger and screwed in it will only run so fast. That seems to have been the secret. The Hitachi I bought off a friend who had 3 in his truck is just tooooo powerful and I was allowing it to go toooo fast. Once I got the right blade/number of TPI and the speed down, all is going well. This week I am going out to buy a good collapsible table saw.

Catigale · Post by **Catigale** » Mon Nov 19, 2007 9:32 am

The melting point of PMMA is only about 150C IIRC...you could cut this neatly with some NiChrome wire and a DC supply to make a small hot wire saw I bet. Would also cut and fuse dock lines nicely.

Divecoz · Post by **Divecoz** » Mon Nov 19, 2007 2:38 pm

Catigale wrote:The melting point of PMMA is only about 150C IIRC...you could cut this neatly with some NiChrome wire and a DC supply to make a small hot wire saw I bet. Would also cut and fuse dock lines nicely.

Dock lines I use my electric soldering iron and the other idea. . . control would be pretty tough and for some reason I can see ME getting burned a lot and maybe . . .a fire or two

Post by **kmclemore** » Mon Nov 19, 2007 2:55 pm

I have a Weller 8200 soldering gun and when I need to cut a lot of rope or do any thin plastic cutting or repair I use this tip on it:

They also make this tip, purpose built for cutting rope:

Shane · Post by **Shane** » Mon Nov 19, 2007 5:41 pm

Divecoz wrote:..... I think want to learn how to wood carve both by hand and with a new 300,000 rpm system I have found....

Yikes! That's ready for high-speed orbit! Must be blue to go that fast.

MacGregorSailors.com

MacGregorSailors.com

Best way to cut Plexi-glass

Best way to cut Plexi-glass