sandblasting 101

I have been asked some questions in the comments of the posts about this job (previous posts 'working on paper', 'the next step' and 'starting fabrication') none of which I have answered so I thought I would do that now.

Alix asks...

How did you come to learn this wonderful craft?...Beyond watching a friend sandblast a crude stenciled rose on a piece of glass, we are completely self taught.  There was no instruction back then and so we just used the ‘trial and error’ method.    

Do you enjoy every stage of the work, or is it stressful?...I do and I don’t.  Doing the intermediate and full size art work is probably my favorite part.  I’d say the most stressful part (aside from deadlines) is the composition and design part.  It’s hard to get started sometimes.  I wander around a lot at this stage until I finally settle down.  The fabrication is just grunt work...cut the stencil, make the diagram, do the sandblasting, in this case cut the stencil again, do the cream etch and finally glue on the jewels.  A lot of steps but at that point it’s just technique.  I still like that part of it too.  I like the drawing part but I also really like the making part.

What happens if the glass breaks?

Have you ever lost a piece?...Well, you know, glass breaks.  It is unforgiving.  It’s doesn’t bend, it doesn’t absorb.  And so, yes, we have lost pieces.  I personally have not broken a piece in a very long time.  Nor has Marc.  But it’s not always in our possession.  Usually, if it gets broken, it happens during installation.  Twice we have lost a piece from having a suction cup fail.  One a nail clipped the edge when the molding was being put in.  But what can you do?  Getting upset does not solve the problem.  You just gotta suck it up and do it over.  And I hate doing them over.

steven (didn’t really ask anything) commented about 

breathing and holding the breath re precision....I too was in the unselfconscious habit of holding my breath while I worked.  I was scolded for this habit over and over so I have tried to learn to incorporate my breath as I work.  But sometimes I do breathe out for a very long time.

Now that the stencils are cut, they go through the sandblasting process.  Peeling the cut pieces of the stencil off in a sequential order, Marc sandblasts those areas as they become exposed.

Here’s the sandblasting booth.

Marc wears the air supplied helmet hanging by the door so he won’t breathe the dust.  The yellow tank on the wall is the filter for the air he breathes.  The small blue cylinder on the wall near the floor is a water trap to keep moisture out of the pressure pot (the metal tank with the green hose in the back) which holds the aluminum oxide he blasts with.  At the end of that green hose is the nozzle he points at the glass when he turns the system on.  It’s run by a large air compressor (not in this picture) and the air is piped in.  The square on the back wall is a filter in front of the exhaust fan.  The brown stuff all over the floor is the blasting grit.

Here are some details from the sandblasting process.

Here’s a little slide show that shows one of the panels from start to finish.  You might notice that the first 6 are upside down (that’s right side up to you).  He works on them right side up, upside down, sideways, whichever is easiest to get where he needs.  Most of this panel was done upside down.

I know that last picture in the slideshow, where all the rest of the tree is etched, it’s hard to see all the detail, but it’s just the photo, the glass all dusty.  The detail of the leaves will show up when it is cleaned off and held up to the light.

Now we have to prepare them for the background etching technique.