Sandblasted ground glass?

[Craig Tuffin]

I know you can Maxwell screens and a bunch of other terrific ground glass options but I have about 4 or 5 backs ranging from 5x7 up to 10x12 that need glass and I'm trying to keep it all affordable.

I know there's a guy on fleabay that with make it to size but I live in Australia so shipping from the US is crazy if I can get a supplier here. It was suggested to me to get 2mm glass cut to size and have it finely sandblasted on one side...does this seem like a good option? It's cheap...only $20 for a 10x12 sheet, but I also want it functional.

Any other options I haven't thought of?

Cheers

[Rick A]

I suppose you could sand blast to make a GG. Theres an article on APUG on making a GG and its not very hard, just a sheet of silicon carbide(IIRC) paper and a couple hours of your time. I made a 4x5 GG using spray glass frost from the hardware. A couple of light coats of the spray and a few minutes of dry time and its done. If you make a mistake, you can clean it off and start over.

[Liam:]

Here are some links I used to make mine..

http://www.apug.org/forums/forum216/...us-screen.html

http://www.dokasphotos.com/techniques/ground_glass/

I don't think sand blasting would be fine enough but I am sure it would work but just not very well.

[John Koehrer]

I used a kit from diycamera but he's out of the country 'til the end of the year. I was too lazy to search out the grit. glass can be had at any hardware store.
It's glass, cut to size & a silicon grit. Takes about 15-20 minutes to do.
Get a sheet of glass to make several GG's & have at it, cut them to size after you've ground them.

[Nathan Potter]

Sandblasting will work but you need to be careful of uniformity across the plate - takes a bit of practice. The grit size is important in order to get the right brightness (scattering) vs too fine of a grit that will produce a hot spot. I think I remember using about 200 grit SiC. I remember that bead blasting was poor.

Nate Potter, Austin TX.

[steven_e007]

Sorry - bit late to reply but I have in the past tried making screens by sandblasting.

It is far too coarse - giving a very rough and crunchy screen. There is something called 'bead-blasting' - where small glass beads are used to give a finer and more uniform effect. Better - But still a bit too coarse for anything other than rough work, IMHO.

Best is to buy some fine carbide grit. You get this from the people who tumble gem stones (google). There are decent instructions on the APUG site, posted recently (Ian Grant).

Basically, use a thick block of glass as a grinding tool, a little #400 grite grinding powder and some water and a 10 X 8 screen is a 20 minute job. You can then use finer grit if you wish to get a really nice fine finish.For smaller screens I personally prefer to use the screen itself as the hand held block and a 10 X 8 as a grinding 'table' - with the by-product that after you've made a few smaller screens you then have a 10 X 8 as well.

I've made many - very easy and can be surprisingly good quality as a basic plain focussing screen.

[Brian Stein]

I know postage to Aus really hurts, but you can buy the grit off fleabay cheaply and for low shipping cost if you cant source it from a local lapidiary supplier (or even auto body shop)

[moto-uno]

Hi
I too have tried sand blasting,very rough,then bead blasting,better,but not satisfactory.I would like to try what is used to clean old and thin auto parts(walnut shells).That may be an idea worth trying.I've even tried fine sandpaper and am using the screen I made of it now.But I've seen how well the fine grit works and it'll be my next try as winter approaches.