New to Sandblasting????

[Lynn Kull]

Hi Gang, I am just starting to add sandblasting to my laser business. I have started out with a bare minimum suction sandblast gun and a bag of grit. I thought if it looks promising I would dive in deeper. I have a couple questions is anyone can help?

I am looking at doing, granite and rocks, wood and some glass.
I am thinking the resists can be cut with the laser....

Resists -
What all can be used and where's the best place to get them?
I know you can buy resists at Crafts stores, but have heard of using laser friendly vinyl. Not sure what that is?
Also what would be needed to say cut 1/8" deep lettering into polished granite?
Can a liquid rubber be used on rocks, something like what is used to coat tool handles? I think it comes in a brush on and spray?

Thanks much for any advise? Lynn

[Rodne Gold]

We use the shiny polyester mirror vinyl as a resist , it ic an be vector cut and weeded as well as raster engraved for extremely fine detial , it will also resist a lot of blasting. It's cheap from sign vinyl places and is laser friendly , BUT is difficult to remove after as it adheres very strongly.
As an alternative , I use a sort of masking tape , paper based - called paper application (transfer) tape that is even cheaper , easier to laser and easier to remove , also from sign supply houses.
BUT this will not allow a deep blast and can erode so it doesnt act as a resist if you overblast , so you need to tread a fine line between depth and losing the piece.
For really heavy blasting , we use the laser to vector cut a thick self adhesive rubber , this is the resist gravestone ppl use , also available from sign supply houses , this will allow serious blasting but cant do fine detial.

[Lynn Kull]

Thanks Rodney, one other thing the grit I bought was a black diamond low silica grit of some sort.... I believe it comes in different sizes, am wondering if it could be used as an all around grit for granite, wood, glass, rocks, etc....?

thanks Lynn

[Mike Null]

I would advise against using anything silica. You need at least 150 grit aluminum oxide. Your system is a siphon system which will get you started but is not really very good for much but cleaning. You need a pressure pot to do a good job efficiently.

There is a better material than aluminum oxide but the name escapes me now. One problem with alum. oxide is static electricity.

[Chuck E Cobb]

Well the best advise I can give if you are wanting sandblasting advise is to check out cuttingedgesandcarving.com/forums. A great bunch of folks and much like this forum, no fighting, just good exchange of tips and ideas. There is just so much it is easier to just read through the forum.

if you do go over, just email me and I'll get you approved quick.

Chuck

[Rick Maitland]

Lynn I have been doing sandblasting for about 3 years now and have experimented on lots of materials. I would say for the type of system you have you will have better luck doing the glass, plastics, woods, and maybe some river rocks. I have a very large air compressor and blast granite at 90 psi with a heavy duty sandmask that is 35 mil thick that is cut with my vinyl cutter. With my $2500.00 setup I have trouble cutting through granite. A commercial system cost around 6K and that is what is used to do the large granite jobs. What takes me 30 min. to do only takes 5 min. with a commercial setup. You will be amazed what you can do with glass though. Use your laser with Laser Tape as a mask. Raster and then blast away. You can also use a photo brasive film that can be purchased at SCM sandblasting (just google it). These are some samples.

[Lynn Kull]

Hi Rick, thanks for the info and pics. I did get a pressure pot and some stencil samples from a Granite supply house. The stencils are Anchor brand 18 mil a white colored rubber like material. I haven't been able to find out what it is made of, do you happen to know if its laser friendly? thanks Lynn

[Rick Maitland]

I have never tried cutting with my laser. In the sign warehouse catalog it says the material is a "polyvinyl-chloride product". Dont have a clue if that is safe or not. I'm sure someone here could tell us.

[Dave Jones]

PolyVinyl Chloride aka PVC is not safe to laser. It generates fumes that turn to acid and eat the metal parts of your laser. It is bad stuff where lasers are concerned. It is no problem for cutting plotters, which use blades to cut.

[Mike Null]

Lynn:

The samples you received are for deep cutting with fairly high pressure. They are much to heavy (thick) for typical glass or marble engraving. 4 mill should be adequate. The key is to get something that has an aggressive tack so that it doesn't blow off.

[Debbie Wheaton]

I'm another newbie to sandblasting - we're adding it to our laser award shop. I plan to use it mainly for curved and odd-shaped objects. What type of mask do you recommend so that I can a clean 'attach' when I'm putting the pre-lasered mask onto the glass/crystal I plan to sandblast? Thanks! All suggestions welcome!

[Arturo Villegas]

Sandblsting can also be fun once you have a good setup.
I am just wondering how do you guys get the lasermask off the laser table to then apply it to a round shape? For example I have to engrave some cups and (no rotary attach) would like to use the lasermask as a stencil to apply and then sandblast.

[Joe Pelonio]

PolyVinyl Chloride aka PVC is not safe to laser. It generates fumes that turn to acid and eat the metal parts of your laser. It is bad stuff where lasers are concerned. It is no problem for cutting plotters, which use blades to cut.
I cut Anchor on the plotter all the time, and in some cases with fairly large
text/graphics it's just as easy to pen plot the lines on paper, apply to the stencil material on the substrate with spray adhesive, and hand cut it with an xacto.

[David H. Mitchell]

Lynn,
What you need is Rapid Mask, which is a brand of photoresist. It is easy to use, and does a good job, even on photos.

Here is a link: http://photobrasive.com/photo_resist_film.php#1


Hope this helps,

Dave:)

[Tom Bull]

If you sandblast glass you will release free silica which when inhaled can cause very serious illness. Just wearing a mask is a help, but your clothes will be covered with silica. You probably don't want to bring that home to the family.