Silicone as sandblasting resist

Hello ! Silicone as resist sounds really interesting. Do you mean
silicone glue, the sealant you can buy as bathtub caulk, or what? I’m
handy with a brush…I could see really using that. I’ve tried a
couple of things as resists, and they all were blasted off, or edges
peeled up too easily (electrical tape, clear “contac” plastic, nail
polish). I’m using a big machine at school that I haven’t learned to
control, but seriously am considering buying my own, so appreciate
any tips on brands, what kind does what, etc. I already have a
compressor, an old one I used to run my natural gas torch (currently
not in use, had problems I didn’t know enough to solve). I’m
interested in something small, for occasional, not heavy use. The air
eraser seems promising-I’d like more info on that if you don’t mind.
Thanks! Lin

Hi Lin, Bathtub caulk should work. However, it might be a little
difficult to position in tight locations.

Another product that would probably work a little easier is rubber
cement. The type available at most office supply stores. It’s a little
thinner than bathtub caulk & could be placed with greater accuracy &
ease. It is also easier to remove & I think there’s a thinner
available for it, if required.

The purpose of the resist used in sand/bead/abrasive etching is to
absorb the energy of the individual particles. Products that have the
adhesiveness, toughness & resiliency of rubber work quite well.
Products that are hard, tend to be abraded by the etching agent just
like the work piece. The degree to which they are etched is dependent
on their hardness relative to the hardness of media & the air
pressure.

Most of the companies that make & market grave stones use a thin
rubber sheet to mask the uncut areas of the stone. They usually use a
carbide grit sprayed from a industrial sized spray gun & compressor.

Dave

Hi, Some years ago I worked as a freelance assistance to a glass
etcher. She used gum arabic in liquid form as a resist. – Madeline

I have just been fooling with sandblasting. Ordinary white glue works
great, if it is thick enough (that is, squeezed straight from the
bottle, not applied in detail with a brush). Anodizing tape (from
Reactive Metals) can be applied and cut through. But my most recent
discovery is that watercolor frisket (liquid latex) can be painted on
in quite fine detail, and holds up well at relatively low
pressures–25-30psi-- though you have to be careful not to touch it,
as your finger will stick and pull it off! Be sure to rinse your
brush every 30 seconds or so, or the frisket will ruin it. But this
is the best I have found for fine detail. I was working on glass–I
would think that a rougher surface (sanded metal) would hold even
better.