1. LapDigest News for Issue No. 34 Thursday 7/24/97
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As you will see, it was a 'slow news day'. We had hardly any postings so I took this opportunity to post one on SAW SLUDGE.
Subject: NEW: Automatic Cab Grinding Equipment
Has anyone had experience (or own) some type of equipment for automatically grinding cab pre-forms and/or domes?
I've seen a pre-former/dome grinder (dop stick holder) in the Graves'
catalog, and some other company's little dop stick holder in some magazine
advertisements. Both claim to automatically grind cab pre-forms and domes.
I'm also considering making one - if I can come up with a design that works. Any suggestions?
Next, I looked in 'LJ INDEX 1947-1991' (another good book to have around)
That is all I can add to this topic. Can anyone else add more?) -- hale
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Subject: NEW: Saw Sludge
One of the first references I remember reading about SAW SLUDGE was by Vince King when he described the problem of Plaster of Paris (PoP) saw particles mixed with Almag; he said it formed an almost homogeneous mass which just would not settle out. Peter Rowe suggested that he pour the oil in double bagged Kraft grocery bags, the whole being supported above a plastic tub. Vince placed a 1/4" mesh circular gravel screen, as used in gold panning, atop a 5 gallon plastic bucket, and placed the bags in that. That setup worked, and in several days much of Almag oil had separated, with the mass of cuttings retaining enough oil to take on the consistency of clay.
My only problem of saw sludge was how to get it out of the saw reservoir without spilling any on hardwood floors. (She doesnt like it when I spill oil on HER floors!) I solved that by getting a hand pump used to pump kerosene from a can to a stove tank; price at Wal-Marts. about $3.50. That gets the reservoir almost empty, then I hand clean the rest.
About the time LapDigest started, a thread appeared on Rocks-and-Fossils
mail list on Saw Sludge . A summary of the messages is given below, with
comments. Permission has been obtained from each author whose item is
Cleaning it and reusing it! That's great! But this begs the issue of what to do with the remaining sludge. I phoned the Environmental Hazards office in several local cities and communities and put the question to them. The answers varied so widely that my only conclusion is that it depends on where you live, and if you want to know for your community, ask your local Environmental Hazards office.
JR had a different idea. He suggested soaking it all up with kitty litter, but acknowledges that he doesn't know what to do with the oily kitty litter. (I would disposed of it just like sludge.) He uses kitty litter for the final cleanup in the bottom of the saw after hand removing the bulk of the sludge.
John describes filtering the trash from his saw fluid by putting the sludge in small paper bags(doubled) which hold a couple quarts of sludge. He puts them in a container, raised several inches above the bottom by wooden blocks or bricks. In several days, he expects that over half the saw fluid will have separated out.
Then came two rather creative suggestions. First, Mark Case saves the material and burns it in an oil furnace in his workshop in the winter for heat. Next, Derek Levin said that his daughter burns the oil from his sludge, screens the residue and uses the fines for pottery glazing. Apparently, this is the kind of material that potters like to use as a glaze. His sludge comes mainly from cutting quartz-type material, along with some beryl and tourmaline and a few others. He noted that each batch gives different glazing results. And his daughter likes the results she gets.
An interesting and humorous response came from Jim Crowe, who said: "Like other suggesters I recycle most of the liquid. My coolant is Al-Mag. The final solution for the nearly solid residue was accomplished almost by accident. While carrying around a bucketful I noted a hole beneath the garden gate where dogs had been burrowing under in order to assist in fertilizing the plants. I dumped it there which immediately discouraged the trespassers. After a few days the sludge had hardened to a cement-like consistency. The next step would be to dig up the newly formed sedimentary rock, re-cut it and once again make small rocks out of one large one. After all, is that not the purpose of the lapidary pursuit? Unfortunately the hardened sludge is not very colorful. Try putting the residue in a form and make stepping stones from them."
Why would it harden into a concrete like mass? Is there a chemical reaction going on, as in concrete or PoP? Or was it just a matter of the liquid slowly draining out and into the ground, leaving behind just a compacted mass of saw dust and chips? Personally I would vote for the later explanation. And if that is so, then all we have done is to return earthy materials to the earth, along with some oily materials. And with the oily materials, some environmental concerns.
Gary Ogg <email@example.com> suggests using a commercial french-fry grease strainer. He uses one to strain oil in his deep fryer at home, and used one when he worked in a restaurant to strain the oil in the french-fryer. He also uses a similar technique at work to remove particles from the motor oil that they use in hydraulic pressure testing. Motor oil, being much more viscous than vegetable or cutting oil, strains much more slowly.
Gary says: "First, there is an expensive type of filter that filters and pumps clean oil back into the cooker, but the less expensive unit is a simple gravity filter that works much like a drip coffee filter. There are two parts; the filter and the filter holder. The nominal size is 10 inches. The filter holder is a cone shaped wire frame with two handles and measures 18 inches across at the handles. It fits well in a 5 gal. bucket. The filters are made of heavy paper, and fit down into the wire frame. These filters will trap all but the finest particles and the oil will be clean enough to put back into your saw. When the oil has finished draining from the saw, you can scrape out the remaining sludge and put it in the filter to recover as much oil as possible. And since oil is considered hazardous waste, dispose of the filter and sludge responsibly.
These items are available at restaurant equipment supply businesses.
A recent price check found a wide range of prices, so shop around.
Thats about it; if any of you have any other suggestions for cleaning
or using or disposing of saw sludge, please write and tell us about it.
Subject: RE: Gem & Lapidary Club Directory - Canada
In Issue 32, we gave Club Directories for Australia and the US. Here
is a great one for Canada. The Directory is put out by the Rock and Mineral
Association of Carada, and the URL is <<http://pangea.usask.ca/~dfs846/rmac/rmac.html>>.
If you want to see what a good directory looks like, look at this one!
Subject: BIO: Bill Cordua
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