Question: what to put under Acrylic?

[Ted Marshall]

I'm cutting small pieces out of colored Acrylic sheets on a 60 watt Epilog Helix. If I leave the paper masking on the Acrylic, it's very time consuming removing it afterwards. I don't mind a little "smutzing" on the Acrylic so I've tried cutting without any masking. The top is fine; the air assist seems to keep things fairly clean.

The problem is the bottom. If I just set it on the hex grid, I get flaming under and end up with scorching and impressions of the hex grid. If I set it on wood or cardboard, it's better but still a little scorching.

what else could I use under that won't be affected by the laser? Would foil (Matt side up) be safe? Maybe some sort of ceramic sheet? Any ideas?

Thanks

[Scott Marquez]

Ted,
Do a google search of images for "laser pin table", you will see what you need to make.
It is the flashback from your table that is causing you problems on the bottom side.
Scott

[Keith Downing]

Here's a thread from last year that talked through this problem and some potential solutions; though some were a bit unorthodox.

http://www.sawmillcreek.org/showthread.php?248355-Pin-Board-to-suspend-work&highlight=home+depot+material

[Erik Goetheer]

Yes, a laser pin table, to raise your material from the underground, is the way to go. Check the RDworks Learning Lab series from the youtube channel Sabarmultimedia, aka Russ. No, it's not commercial channel, but Russ is showing and telling great things that he does with his Chinese laser. Ánd he is using a pin-table quite often. I believe there is even one episode in which he shows how he made it, or them because he also 'learned on the job'. (very easy to do yourself though).

[Keith Outten]

This Corian vector table was my solution. It will absorb the laser energy. The beam will cut the Corian when its hit so its a sacrificial table but it should last ten to fifteen years. Anyone here who owns a CNC Router can make one for you.

[Bill George]

I'm cutting small pieces out of colored Acrylic sheets on a 60 watt Epilog Helix. If I leave the paper masking on the Acrylic, it's very time consuming removing it afterwards. I don't mind a little "smutzing" on the Acrylic so I've tried cutting without any masking. The top is fine; the air assist seems to keep things fairly clean.

The problem is the bottom. If I just set it on the hex grid, I get flaming under and end up with scorching and impressions of the hex grid. If I set it on wood or cardboard, it's better but still a little scorching.

what else could I use under that won't be affected by the laser? Would foil (Matt side up) be safe? Maybe some sort of ceramic sheet? Any ideas?

Thanks
Go to your local home improvement store and purchase some 4 inch or whatever size you think will work ceramic tile. Space them out under the acrylic and cut away. I usually flipped them over so the unfinished side was up.

[Kev Williams]

Your table is fine.

1: Transfer tape. Get some if you don't have some
2: remove all plex masking, both sides
3: replace with transfer tape, BOTH SIDES. Squeegie down well, don't want it loose.
4: cut plex
5: get a plastic bucket or tub, add hot water and some dish soap.
6: put your cut pieces in the hot soapy water
7: 5 to 10 minutes later, you'll find most of the transfer tape has fallen off the plex. What didn't removes very easily.

[Ron Gosnell]

I cut out several little discs just to use as spacers. Just a little bigger than the honeycomb so they don't fall through. If you know where your cuts are going to be just place them away from there. Not a big deal even if you laser through them. They are just scrap pieces.

[Ted Marshall]

Your table is fine.

1: Transfer tape. Get some if you don't have some
2: remove all plex masking, both sides
3: replace with transfer tape, BOTH SIDES. Squeegie down well, don't want it loose.
4: cut plex
5: get a plastic bucket or tub, add hot water and some dish soap.
6: put your cut pieces in the hot soapy water
7: 5 to 10 minutes later, you'll find most of the transfer tape has fallen off the plex. What didn't removes very easily.
when you say transfer tape, is this what you mean? https://www.amazon.com/Vinyl-Ease-Application-Transfer-Silhouette/dp/B008CEQR26

Also, has anyone tried teflon sheets for heat presses? Would that survive lasering?

Thanks

[Kev Williams]

Not sure about that stuff, guess it would work-- but what I use is 15" wide medium tack paper transfer tape, designed for vinyl signage...
349241349242

I always use this on both sides of Rowmark. When cutting thru the original masking or no masking, there's always a bit of a rolled edge on the top surface from the heat. When using transfer tape, the rolled edge is reduced greatly or eliminated altogether. And it keeps the backflash on the back side to a bare minimum. It takes a bit of time to put on, but it's like 1 or 2 minutes on, and with hot soapy water it comes right off, and I get pristine parts. Cleaning up the soot on top and the mess on the back when not using it can run into half-hours, and pristine parts are rare...

Now if only there was a way to not have the sides turn gooey when cutting this stuff and other extruded acrylics! --but that's not an issue with cast... :)

A full 15" roll costs me about $45 and usually lasts over a year, and I also use it for vinyl signage, so it's reasonably cheap to use!

[Keith Downing]

when you say transfer tape, is this what you mean? https://www.amazon.com/Vinyl-Ease-Application-Transfer-Silhouette/dp/B008CEQR26

Also, has anyone tried teflon sheets for heat presses? Would that survive lasering?

Thanks

That is indeed transfer tape. There are a lot of different kinds. When buying you want to consider:

Size of the roll (width)
Tackiness; I prefer high tack, especially for wood projects, many people here recommend medium tack
Finally, you can choose between white paper, brown paper, or clear.

Just depends what your specific project needs are.

[Mike Null]

I buy high tack. It's not really that sticky. They come in 54" logs from sign suppliers and they will cut it to several widths for you at a small extra charge.

FWIW, the high tack works better on wood surfaces which is the reason I prefer it.

[Ted Marshall]

Your table is fine.

1: Transfer tape. Get some if you don't have some
2: remove all plex masking, both sides
3: replace with transfer tape, BOTH SIDES. Squeegie down well, don't want it loose.
4: cut plex
5: get a plastic bucket or tub, add hot water and some dish soap.
6: put your cut pieces in the hot soapy water
7: 5 to 10 minutes later, you'll find most of the transfer tape has fallen off the plex. What didn't removes very easily.
Thanks for this info.

it turns out that the Techshop where I use the lasers has a big roll of transfer paper, out by the vinyl cutter and silk screen machine. It works great. However, even after an overnight soak in soapy water, the paper must still be peeled off. None of it floated off. It is easy to peel but with hundreds of small parts, it still a job.

I'll probably start covering only the bottom and leave the top bear. I don't mind a little grunge on these parts.