How to make a Ground Glass

After researching the issue on how to manufacture a Ground Glass, I

came across many techniques. Some indicated to frost Plexiglas with

diluted acetone, some others recommended to use automobile valve

grinding compound, another proposed to get some fine grain

carborundum powder and rub it on the required surface of the glass.

 

First, obtain a cheap picture frame at your local crafts store.

Make sure that the glass that comes with it is not colored, some are

greenish looking. The "nominal" size of this picture frame should

be 5x7, as it has a glass that approximates the required dimensions.

 

To frost the glass:

 

Using two kitchen paper towels as a base, put the glass on a flat

surface. Then use your handy rectangular sharpening stone, the side

that has "fine" grain. Oil the stone until its surface

becomes "pasty", the stone is ready for grinding.

 

Rub this oiled stone in circular motion on the glass. Make sure

that you put a good concert on your stereo, and by the end of the

concert, the glass will be ground.

 

The fineness of the grind depends on the coarseness of the stone.

The finer the better. Possibly two passes could be done, one semi-

rough, the next fine, to achieve the desired grade of frost.

 

This eliminates all exotic techniques on how to make a mess in your

kitchen with acetone and grinding powders.

 

Hope that this is useful to those that want to grind their own GG.

I made a GG screen for my Ihagee 6x9 a few months ago.

 

I had a glass shop cut me a piece of acid etched glass to size and mounted it with the etched side towards the lens. Works perfect.

 

I can't think of his name or the link, but there's a guy with a website that makes GG screens. They are very reasonable and reputed to be excellent screens.

That'd be Dave at SatinSnow. I've never heard about bad word about their glass, and the prices are incredible -- $25 shipped for a 4x5, last I checked. Made to order, so you won't get turned around overnight, but it's worth the wait. I'm hoping to get a couple of his glasses for my plate cameras sometime soon...

I would order one just to have a spare for travel. You probably will spend close to that trying to make your own and it won`t be as good.

 

I would not do a grinding stone. I would do as they do with telescope

mirrors. Use two peices of material with grinding compound between. wash well between grades of abrasive.

What I presented is a technique on how to come up with a GG for minimal cost and labor.

 

As to the other techniques, they are quite valid, but they do not point to a homemade GG. The telescope approach is the best, will give the finest "grain" in the glass, but the time and expense to find the grinding material seems to be quite extensive to me.

 

A good Arkansas sharpening stone can be found in any hardware store and fine oil is readily available ( automotive transmission oil, olive oil... ). In my experience, and only MY EXPERIENCE, after making two GG's, the method that I presented has been satisfactory for the image resolution required.

 

I have a TOYO 4x5 model D ( I think?) and the OEM GG that came with the camera is not as "fine" as the one that I manufactured myself.

 

I hoped that my posting would be an inexpensive alternative to purchasing a GG, or to go on a search for exotic grinding materials. To give confidence that, if one's GG breaks for some reason, that it is an easy thing to fabricate a replacement by oneself.

 

I would like to thank the authors of the responses to the posting, since they have expanded the horizon as to manufacture, technique and availability of GG. This is a benefit for all. Thank you.

You can lead a horse to water but can not make him drink. Every one has their own way of doing things, if the grindingstone works for you with available materials , more power to ya. A piece of sandpaper will work as well.......You may want to take your research a little further though ...... ..... I can tell you this much , historically that is not the way it is done professionally and in most cases it is not how it is done by most ametures as well....... The abrasive between two peices of glass will give a much finer uniform surface........Obtaining small amount of grits in various sizes is availabe at any lapidary shop or sandblast supply ...... Glass Acid etching solution is available at most stained glass shops, as well as window Glazing supply houses ...

Thank you Mr. Cremati:

 

Your knowledge is invaluable. I will look for etching acid in the glass shops in my area. This seems to be so much easier than to get bored grinding the glass for a full half hour. Midless work.

 

I guess that after this discussion everyone will know how to manufacture a GG if need to be and all the alternatives possible.

 

The sharpening stone worked for me, because I had it laying around the house and after the first trial, I considered that it was a good easy way to go. Mind you, the "grain" of the glass came out really fine, one does not have to press too much on the glass. I tried also the sandpaper, it works, but it so much more time consuming and a good supply of sheets is needed.

 

Thank you.

I haven't done any research on this as I use a Beattie but has anyone ever done any sandblasting of glass? I'd like to know as I have access.