help with cutting plexi/lucite

[Posidon42]

Right now I am working on building a reservoir for my water cooling system so my Mag 2 or 5 can be submerged. I was thinking about cutting the plexi or lucite to size on a table saw then dadoing (word?) the corners so I would have a really nice fit when it gets put together.

Can this be done or will the table saw just melt the plastic?

[dowmace]

if you use lucite it will melt but it won't seal back up after you make the cut.

[Posidon42]

not sure i understand what you mean

[Smirabi]

be careful with saws melting plastic, especially because liquid plastic gets all over the place and burns like hot oil. what wont melt mlexi or lexan is a jigsaw. and with a little care, you can get super straight lines as well. i'm not sure about lucite.

[skidooosl]

i used plexi to make my fan shroud.... i cut it with a jigsaw and yes.... it would melt right back together, i found if i made the cut about 3 times i could finially get it apart but the edges are far from nice.... lol

[touser]

plexi or lexan cuts just fine on the table saw, at least in my experience.

[Smirabi]

wait a minute, skidoosl, are you saying that the cut you made with a jigsaw would melt back together? that's strange. i had no such problems. make sure that you're using a medium tooth bit that is sharp, so it is cutting through instead of heating through.

[skidooosl]

i had a blade that said it was for cutting plastic.... the plexi was 1/4 in thick so that may have been why

[UberBlue]

For cutting with a table saw try to use a 120 tooth triple-chip blade, or a blade with as many teeth as you can muster that's in good condition. Table saw blades have a lot more thermal mass than a jig-saw blade, hence take alot longer to heat up to the point of melting plastic. Plus they're spinning through the air at a high rate of speed, which tends to cool them effectivly.

Or the quick and dirty method that works for up to 1/4" material. Go to home depot and you will find a tool called an acrylic scoring knife. They're dirt cheap and right next to the plexi-glass stock.

They are a little deceptive to use. You intuitivly pick it up and want to use it like an exacto knife. That's the wrong way to use it. twords the handle is a hooked shaped part of the blade. Set that part of the blade against the acrylic and PULL along a straight edge. The hook part acts like a chisel and carves a groove. After a few passes it'll snap right along the score.

[skidooosl]

sounds good, ill try that... better than my jig anyway. is it easy to score 1/4 plexi? seems pretty thick

[Nightingale]

I bought a special aluminum/plastic blade on ebay for table and circular saws and it cuts through polybarbonate like nothing and didn't melt the edge at all and left it nice and smooth. I would recommend getting one of these blades. I believe you can get one from mcmaster or if your lucky like me you can pick one up on ebay.:D I would assume this would work just as nice with plexi. I have also cut copper and aluminum and it leaves a pretty clean edge and really straight.

[UberBlue]

Originally posted by skidooosl
is it easy to score 1/4 plexi? seems pretty thick

Each pass will carve out abot a 1/32". Try to score at least 1/4 of the way through. It doesn't take long.

Also, put a piece of pipe directly under the score and apply pressure evenly tto both sides when you are ready to snap. (the plexi, not you. Snap that is.)

PM me if you have any more questions as I've been messing with plexi alot lately, or ask here to make it public knowledge.

[[OC]Lucifer]

Into the same problem with melting, so I just used a coping saw with a fine tooth metal blade. With a coping saw you can rotate the blade, allowing you to make those detail cuts.

[jimstandard]

whats a coping saw, havent heard of that one

[Posidon42]

wow, lots of help. The reason I was looking for the table saw is because I intend on building a reservoir and it is easier to make repeatable dimensions with the table saw.

I will definitely try to look up one of those blades as I am sure my local wood shop won't like me using their wood blades on the plastic.

Best I found on McMaster is $20. That isn't too bad if I am going to be doing a bunch of cutting.

[[OC]Lucifer]

Is typically used by jewelers and the like. http://www.zonatool.com/35-670.gif you can unscrew the handle which unlocks the blade so you can rotate it, then retighten the handle to lock it into a new angle. Works quite good.

[RoadWarrior]

You can find those in dollar stores sometimes, but if you do, pitch the blades that come with it and buy some decent ones from a good old fashioned hardware store.

Those I would say are good for curves up to 2 inch radius, but for finer work than that, a "fretsaw" or "scroll saw" of the hand tool variety is better. Those have a shorter blade, but a longer arm to reach up to 10inch into a piece of work. The blades are thinner and can usually be turned in their own cut. One can start with a really small pilot hole. However they are somewhat challenging to cut straight with, unless the type of frame has a lot of spring so the blade is held in good tension.

Road Warrior

[UberBlue]

Originally posted by Posidon42
wow, lots of help. The reason I was looking for the table saw is because I intend on building a reservoir and it is easier to make repeatable dimensions with the table saw.

I will definitely try to look up one of those blades as I am sure my local wood shop won't like me using their wood blades on the plastic.

Best I found on McMaster is $20. That isn't too bad if I am going to be doing a bunch of cutting.

The table-saw is my prefered method.

When you get ready to start glueing, try to find some IPS weld-on 3 or 4. Try your local glass shops, you'd be supprised what they carry.

[Posidon42]

well I always had a penchant for doing stuff right the first time. Even though it might be more expensive up front, I think the table saw method will be great in the long run. Maybe then I will have an excuse to make an acrylic case one day :)

[jimstandard]

i was just watching monster house and they were cutting plexi on a table saw, and it appeared that they sandwiched the plexi in cardboard and then cut it on the saw, it was fast and came out really smooth

[Posidon42]

well that is an idea.

[dorimon81]

I used a jigsaw for cutting my lucite and it cracked as soon as I made a cut about 3 cm deep. I would suggest using a table saw or even a hack saw. I use a hack saw now for cutting my lucite.