Masking for sandblast

Does anyone know of a better way to mask off areas to be left
bright, when sandblasting finishing close by areas? I have painted on
wax with some success. I am working in sterling silver.

Thanking you in advance.

Sincerely
Jim

Thick coats of rubber cement might work. You need something that is
soft rubbery or soft plastic. Might be able to use the tool handle
dipping stuff you can get in hardware stores. Mold making latex might
work. I do larger work and there is special resist just for the work.
Heavy plastic sheets with or without adhesive on the back. Duct tape
might even be a way or even thicker is a tape used to wrap gas pipes
(natural/propane) that is 10+++ mils thick. Glue down some thick
plastic sheeting. Looks like trial and error time.

John Dach

To use as a mask when sandblasting… I always used to use
electrical tape that I’d cut carefully with a craftknife. It worked
well most of the time.

Does anyone know of a better way to mask off areas to be left
bright, when sandblasting finishing close by areas? I have painted
on wax with some success. 

Rubber cement, masking tape.

I always use blue painter’s tape to mask off areas for sandblasting-
works great!

Steph Swanson

Hi Jim

I did a bit of sandblasting of sterling in the past. I got very crisp
edges by using 3M colored tape (you can usually get this in a
hardware store) that I cut with a craft knife (E-Xacto). I worked on
a piece of plexiglass, put the tape on the plastic, cut it and then
transferred it to the metal. Using the point of the knife was very
helpful with the transfer process. I had a few extremely miniscule
slivers of tape be removed during the sandblasting process but even
those usually stood up to the blasts.

HTH
Linda M

Does anyone know of a better way to mask off areas to be left
bright, when sandblasting 

The best thing is tape, preferably masking tape. Other than that we
use fingernail polish to mask most everything (plating…) I hope
someone has a better idea, too…

Try this product "latex #74 " sold by seattle pottery supply inc.
206-587-0570. we are using this stuff for 2-3 years now. and its
great. good luck

Charles

Hi Jim,

Does anyone know of a better way to mask off areas to be left
bright, when sandblasting finishing close by areas? 

I’ve not tried it, but several coats of rubber cement may work. I’ve
seen several other industries that do sandblasting for decorative
purposes use thin sheets of rubber as a ‘resist’. Since the depth of
sandblasting in silver/gold work is usually not great, several coats
of rubber cement may do the trick. It’s usually easy to clean off
also.

Dave

In Media blasting, the first questions you have to ask yourself is.

What is the type and hardness of the media I'm going to use? 

What is the size of the nozzle at the discharge? 

What is the distance I can keep the nozzle away, from the item
being blasted? 

What is the size of the grit I'm using, whether it is walnut
shell, glass bead, garnet, steel shot, plastic or sand? 

What is the effect that I'm going for surface finish, texture,
deep etch,removal of paint,curd or other surface contaminant, or
prep of the surface for another type of coating. 

As of the above will determine you choice of mask or friskit
material. If you are using a small abrasive blasting unit either home
made or bought. The kind glass artists use a:

The Paasche AEC Eraser set works like a miniature sandblasting tool!
The long lasting carboloy tip removes old paint, rust, or corrosion
without damaging the undersurface. It’s powerful enough to carve
designs in wood or to etch on glass and can also be used for
cleaning fine instruments. 3045 PSI is required.

Dick Blick’s or most hobby shops art supplies stores have them.

Or a small cabinet type with a smaller nozzle. You can use a lighter
masking agent.

Any tape, from cellophane, packing, duct or the stainless steel
muffler tape will work. Any paper or card board will also work, For a
mask held in the hand or taped in place for larger areas. Cling wrap,
plastic wrap painting plastic mask can also be used. You can use the
afore mentioned tapes or make up your own with a spray adhesive to
just about anything.

Contact vinyl shelf paper/plastic makes a great low cost mask with
easy removal. Old bumper stickers or the lazer/inkjet printing
sheets work.

The best way is to make up a test board with a number of samples and
try blasting it at assorted pressures and distances.

As to liquid applied masks the only thing you have to remember is.
It has to be removed from what ever you apply it to. if the surface
is rough or lots of highs and lows. It can be a real pain if there
isn’t a solvent that will remove it it can ruin a piece. But nail
polish, dip it rubber coating, rubber cement, thinned caulking,
latex rubber and heavy layer of acrylic paint can be used.

The rubber mask that has been mentioned for blasting is
about.025.030 and up. A monument maker would use a thicker mask for
heavy carving. You could use rubber lab aprons with spray glue. A
lot of the monument people will sell a small section if you might
call and ask them, before popping in asking for some.

Electrical will work and you can get it in wide widths at supply
houses. But be aware some brands leave a sticky mess that needs to
be removed.

For texturing or patterns on the surface. Something else for your
consideration is blasting thru metal or fiberglass or plastic mesh
or screens. laundry bags and the vegetable bags. Along with the
plastic protection wraps that some drill bits and mill cutters come
in.

The idea of cutting on plastic is nice, but the use of plate glass
with the tape on it and cut with an #11 xacto blade is the sign
industry standard when doing free hand work. Always use a fresh
blade each session. Another tip is to use a burnisher like a bone
folder, plastic pen top or wooden polished clay or wax tool along the
edge of the mask if it is sheet goods. As if any media can get under
the mask it generally will all follow and peel up.

Keeping the nozzle at 90’ to the surface that you are blasting works
to insure a crisp edge to.

Also if you are using masking tape to lay down a liquid mask, make
sure you try it out on a test panel before the piece. as some
liquids will peel up with the tape if they aren’t cut with an exacto
first.

Remember, always do a test before starting in on the item you are
doing. As it really does save a lot of do overs! Ben there, redone
that, to many times.

And the last item, as it has been discussed on this site before. But
do to the new people and the people that don’t do searches on the
site. When you SAND blast using SAND/SILICA etc.

You can develop silicosis:

Silicosis is a progressive disease that belongs to a group of lung
disorders called pneumoconioses. Silicosis is marked by the
formation of lumps (nodules) and fibrous scar tissue in the lungs.
It is the oldest known occupational lung disease, and is caused by
exposure to inhaled particles of silica, mostly from quartz in
rocks, sand, and similar substances.

You can read more here
http://www.answers.com/silicosis?cat=health&gwp=13 Or at your
favorites search engine.

Hi Jim

I don’t know if it will work on metal but when I was doing glass
blowing we used a green rubbery material called ‘butter-cut’…cause
it cut like butter. Ba-dum ching. I don’t know if that’s the
professional name for it but it is coated with a plastic on one side
to keep it clean and clingy and the rubbery-side is easy to draw on
and cut with an x-acto. It stuck very well to glass and I imagine it
would do the same to highly polished silver.

Good luck.
Cheers
Rachel

'Buttercut" does stick metal and other materials as a sand and glass
bead resist. Patterns are easily cut with x-acto type knife. It is a
3M Sandblast Stencil product.