Oramask 813

[gary l roberts]

I USE ORAMASK 813 (sign warehouse) IN MY CNC WORLD. DOES ANYBODY KNOW IF ITS LASER-ABLE ie. I DON'T WANT TO GAS MYSELF TO DEATH.

THanks

[Gary Hair]

a quick google search found this:
"This rigid, transparent blue PVC film has been formulated for stencil applications, especially spray and paint techniques" - so, no, you can't laser it due to the pvc. Some here will tell you it's ok, but you need to know the risks and assess them for yourself.



I USE ORAMASK 813 (sign warehouse) IN MY CNC WORLD. DOES ANYBODY KNOW IF ITS LASER-ABLE ie. I DON'T WANT TO GAS MYSELF TO DEATH.

THanks

[gary l roberts]

THanks - not worth any risk.
Anybody have a mask they would recommend for laser and paint?

[Duncan Crawford]

Gary,

I use a paper based transfer tape-- 12" GT Paper Transfer Tape -- got mine from H&H Sign Supply. It uses a rubber adhesive. You'll get opinions on whether to use medium or high tack versions; I've used both. If you're cutting unfinished softer wood like a Baltic birch, the high tack version can tend to pull small fibers when you peel the stuff off. On finished materials either will work well. When I make signs for the Appalachian Trail, the paper goes over my pre-cut and pre-painted sign blank... roller it down tightly to prevent weeping. Laser thru it, do a coat of the background color in the lettering to seal the tape edges, then when that's dry paint with the lettering color. Pretty much the same method as for your CNC work.

duncan

[Chuck Stone]

I'm not sure what you're using it on, but often the dedicated resists are
used for stone. I do some work for a stone company and found that
there are some tricks you can use to avoid the higher cost of some resists.
I use the paper transfer tape also (medium tack) and us a small steel bristle
brush to work the tape into the substrate. Slate has a lot of texture, so you
want the tape hugging all the contours. Polished stone can also be burnished
with polished wood to get a good bond between the tape and stone. I use
the back side of a wooden clay carving tool .. just because I had one handy.

If I'm going to sandblast the stone afterwards, I find the tape can hold up OK
for light blasting on soft stone like marble. Mostly that's just to get the residue
out of the engraved areas. (transfer tapes can leave residue, so can burned
stone)

But if I'm blasting for depth, I'll cover the transfer tape with another layer of
Duck (brand) HP260 shipping tape. That allows me to do a heavy blast and
get depth in the stone before painting. I've tried other brands of tape, but
they tend to leave residue behind that acts like more resist, so you don't get
a good blast. The HP260 lasers away clean.. but takes a bit of power to get
thru it.

MOST IMPORTANT if you do this.. don't overlap the tape. You'll need more
passes and get varying depths of cut. Lay down a strip and then butt the
other strips up against the first one till you have full coverage.
It would be perfect if it came in 12" rolls..

I got the Duck at Staples because it was right here, but they're not cheap.
It is much more expensive than other shipping tapes (but again.. those
didn't work for me) but still less than buying resist.