Sand Blasting Media for Glass

[CalyxAnn]

Hi, all!

So, my question is this…

I just got a sandblasting cabinet and am excited to start using it with my fused glass, but I was curious as to the different media that folks are using to sand blast. I’ve talked to some who use aluminum oxide, but the studio where I used to work used silica carbide.

What would be the difference in application or results?

Thanks in advance!

Carrie Strope

http://www.CalyxGlass.com

[Stephen Richard]

Many report that Silicon Carbide promotes devitrification.  And that aluminium oxide does not.  Some worry about the health effects of SC, AlOx apparently does not have those health concerns.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/   and  http://www.glasstips.blogspot.com/

[Anonymous]

Silicon Carbide (SiC):

– more expensive

– harder (9.5 on Mohs hardness scale)

– does not dull with use – fractures and creates sharp but finer (but still effective) grit

– creates light at impact spot (triboluminescence)

– not ideal for blasting surfaces to be clear capped (creates “fogging”). Jury is out on cause – some think it is devit and others suspect that the deep pits caused by aggressive blasting might trap air, causing small bubbles. Not an issue on uncapped glass.

Aluminum Oxide (AI203)

– more likely to be available locally

– 9.0 on Mohs

– Dulls with use (doesn’t last as long as SiC)

– creates static electricity when blasted – dust sticks to glass, cabinet, etc

I use SiC (I do a lot of material removal in my work) – but there are days I wish I used AI203. I’m sure if I used AI203 there would be a lot of days that I wished I had SiC.

Unless you plan on a lot of aggressive (deep) carving then you are probably better off with AI203.

Most importantly – NEVER use plain old sand.  Blasting with sand releases “free silica” dust into the air — which is the same nasty stuff that gives coal miners silicosis (aka black lung disease).

---

Paul
FusedGlass.Org
Helios Kiln Glass Studio
PaulTarlow.com

 

[Buttons1]

We are investigating investing in a small sandblasting setup.  Do you have any recommendations or equipment to check out or equipment to avoid?  We really don’t know anything about it, except that we took a class in Winnipeg from Patty Gray and she finished one of our pieces using a sandblaster and we like the matte finish that resulted.  The studio there had a really large cabinet that I’m sure we can’t afford and don’t have space for, but we’d like to be able to finish small pieces.  Thanks.

[pat_d]

Paul, what grit size do you recommend for sandblasting if using silicon carbide?  Vs. what size if using aluminum oxide?

Primary intended use is prevention of devit; sometimes etching a stenciled/masked design.

Thank you!

[Anonymous]

For removing devit, any size does the job.

For blasting designs with finer detail you’ll want finer grit.

If you are sanblasting and then slumping for a matte finish, finer grit will give you a softer, smoother result.

Unless you need to go fine, the coarser stuff is a better value as it lasts longer before breaking down to dust-sized particles.

I generally use 120 as general purpose size – fine enough for most carving, nice finish on matte, and lasts a resonably long time.

---

Paul
FusedGlass.Org
Helios Kiln Glass Studio
PaulTarlow.com

 

[Teresafahey]

Hi Paul. Thank you sincerely for all the good info re sandblasting, as well as so much helpful advice on Facebook!

You say you recommend 120 grit as a good general grit for sandblasting devit and etching glass. Would that be SiC or Aluminum Oxide? Teresafahey

[Author]

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