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- Feb 21, 2003
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I just did a couple of batches of DE mixed with two ton epoxy. Should know something in the next day or so on that front. Mark
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Copy of description of Cutler's Pitch
- Thread starter ddean
- Start date
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- Mar 26, 2002
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added alternate to the bad link a few posts up,
and here's what government sources & others have to say
for good measure:
www.osha.gov/dts/chemicalsampling/data/CH_266690.html
www.cdc.gov/niosh/pel88/68855-54.html
www.cdc.gov/niosh/pdfs/crystal-silica.pdf
waltonfeed.com/grain/faqs/ive.html
www.reade.com/Products/Minerals_and_Ores/diatomaceous_earth.html
and lastly,
(note tripoli polishing powder included here)
from an msds:
"11. Toxicological Information
Toxicological Data:
No LD50/LC50 information found relating to normal routes of occupational exposure.
Silica, Amorphous:
- diatomaceous earth: investigated as a tumorigen.
Silica, Crystalline:
- tripoli: investigated as a tumorigen.
- tridymite: investigated as a tumorigen and mutagen.
- quartz: investigated as a tumorigen and mutagen.
- cristobalite: investigated as a tumorigen.
- fused: investigated as a tumorigen.
Carcinogenicity:
For Silica, Crystalline:
- Cristobalite (14464-46-1), quartz (14808-60-7), and tridymite (15468-32-3) are listed by NTP as known to be a human carcinogen.
- NIOSH considers cristobalite, tridymite, quartz, and tripoli (1317-95-9) to be potential occupational carcinogens"
and here's what government sources & others have to say
for good measure:
www.osha.gov/dts/chemicalsampling/data/CH_266690.html
www.cdc.gov/niosh/pel88/68855-54.html
www.cdc.gov/niosh/pdfs/crystal-silica.pdf
waltonfeed.com/grain/faqs/ive.html
www.reade.com/Products/Minerals_and_Ores/diatomaceous_earth.html
and lastly,
(note tripoli polishing powder included here)
from an msds:
"11. Toxicological Information
Toxicological Data:
No LD50/LC50 information found relating to normal routes of occupational exposure.
Silica, Amorphous:
- diatomaceous earth: investigated as a tumorigen.
Silica, Crystalline:
- tripoli: investigated as a tumorigen.
- tridymite: investigated as a tumorigen and mutagen.
- quartz: investigated as a tumorigen and mutagen.
- cristobalite: investigated as a tumorigen.
- fused: investigated as a tumorigen.
Carcinogenicity:
For Silica, Crystalline:
- Cristobalite (14464-46-1), quartz (14808-60-7), and tridymite (15468-32-3) are listed by NTP as known to be a human carcinogen.
- NIOSH considers cristobalite, tridymite, quartz, and tripoli (1317-95-9) to be potential occupational carcinogens"
- Joined
- Jan 26, 2002
- Messages
- 2,737
Like many other things, this issue is complicated ... complicated beyond what many of those in those in this country who make and propose regulations are willing to accept.
Asbestos occurs in several forms--only one is is believed to be responsible for the documented health problems of asbestos. Silica ... well this a big can o'worms. Your beer bottle is silica. And your windows. Is there a particular form of silica that has the same properties of asbestos that leads to severe resporatory problems? Yes, there is. And there are forms that do not.
Professional glassblowers can also get "silicosis". The thing is, that they are using glass. Glass is not crystalline. But it is silica. Glass is a super-cooled liquid that is an amorphous solid at usual temperatures. Glass flows, but very slowly, it has been documented that old windows are thicker at the bottom. Glass is basically silica. But so is beach sand, so is the skeleton of a diatom. Back to the glassblowers, when they prroduce a hole in an object by intensely heating a part and blowing out a very thin portion they are producing small, inhalable particles of non-crystalline silica. The size and shape of these particels seem to be the problem, not what they are made of.
The issue isn't whether these particles are crystalline or not, (glass is by defintion a super-cooled liquid) the issue here is their size and physical properities.
Anybody who has had an itchy experience with fiberglass vs the pleasurable experience with a beer bottle or a sand castle can get an idea of what I am talking about.
Basically it looks like the processing of some diatomaceous earth makes it resemble fiber glass instead of chalk dust, which unrefined diatomaceous earth looks like in the natural raw forms.
Even in the raw form it is a superb filtering agent, and used in the food industry. I myself have used it in the laboratory, and it carried no warnings.
My suspicion is that there are repositories from salt-water deposits that can only be made into acceptable filter agents by a process that happens to convert the silica to a crystalline form of a respirationally hazardous size and shape. They must be abundant eonough that the extra processsing required makes them less expensive than utilizing freshwater deposits for certain purposes.
What does all this shyte mean?
After stripping away all the political BS, there really is a best choice of stuff to use for a particular purpose. The art is in balancing the ALL THE COSTS vs. all the BENEFTS.
We humans have a long way to go in this regard, including learning what the cost and benefits are.
*Apologies for mounting the philosophical soapbox*
Now sort of back to the topic this thread orginally adressed.
Mark, what is so nasy about the DE that you use?
Asbestos occurs in several forms--only one is is believed to be responsible for the documented health problems of asbestos. Silica ... well this a big can o'worms. Your beer bottle is silica. And your windows. Is there a particular form of silica that has the same properties of asbestos that leads to severe resporatory problems? Yes, there is. And there are forms that do not.
Professional glassblowers can also get "silicosis". The thing is, that they are using glass. Glass is not crystalline. But it is silica. Glass is a super-cooled liquid that is an amorphous solid at usual temperatures. Glass flows, but very slowly, it has been documented that old windows are thicker at the bottom. Glass is basically silica. But so is beach sand, so is the skeleton of a diatom. Back to the glassblowers, when they prroduce a hole in an object by intensely heating a part and blowing out a very thin portion they are producing small, inhalable particles of non-crystalline silica. The size and shape of these particels seem to be the problem, not what they are made of.
The issue isn't whether these particles are crystalline or not, (glass is by defintion a super-cooled liquid) the issue here is their size and physical properities.
Anybody who has had an itchy experience with fiberglass vs the pleasurable experience with a beer bottle or a sand castle can get an idea of what I am talking about.
Basically it looks like the processing of some diatomaceous earth makes it resemble fiber glass instead of chalk dust, which unrefined diatomaceous earth looks like in the natural raw forms.
Even in the raw form it is a superb filtering agent, and used in the food industry. I myself have used it in the laboratory, and it carried no warnings.
My suspicion is that there are repositories from salt-water deposits that can only be made into acceptable filter agents by a process that happens to convert the silica to a crystalline form of a respirationally hazardous size and shape. They must be abundant eonough that the extra processsing required makes them less expensive than utilizing freshwater deposits for certain purposes.
What does all this shyte mean?
After stripping away all the political BS, there really is a best choice of stuff to use for a particular purpose. The art is in balancing the ALL THE COSTS vs. all the BENEFTS.
We humans have a long way to go in this regard, including learning what the cost and benefits are.
*Apologies for mounting the philosophical soapbox*
Now sort of back to the topic this thread orginally adressed.
Mark, what is so nasy about the DE that you use?
Aardvark
Gold Member
- Joined
- Nov 26, 2002
- Messages
- 5,064
Inspired by the DE suggestions, I fixed the handle of my bone-handled GRS by taking the handle off, super-gluing the big piece that had broken out, and filling the handle with a mixture of DE and epoxy. Didn't try it out for strength first. The mixture had the look of a water/cornstarch paste: kind of transparent. I suppose that adding more DE would have made it more substantial looking, but I wanted to make sure I had enough glue in the mix.
Didn't really care for the way it looked on the cardboard (mixing platform), but none dried on the bone, so I can't comment on how it would match colors. I had completely blue-taped the handle because I'm such a slob while gluing.
I had some leftover tile grout (non-sanded, antique white) that I played with. It made a much nicer color when mixed with the epoxy.
Didn't really care for the way it looked on the cardboard (mixing platform), but none dried on the bone, so I can't comment on how it would match colors. I had completely blue-taped the handle because I'm such a slob while gluing.
I had some leftover tile grout (non-sanded, antique white) that I played with. It made a much nicer color when mixed with the epoxy.
- Joined
- Feb 21, 2003
- Messages
- 1,487
firkin
Some of my fears of DE may just be in my head I suppose. There is a couple of reason that I dislike it as much as I do. The warnings that are on the pacage are part of it. The "safety training" that I got when I worked at a pool store covered DE as much as it did several of the other explosive/poison chemicals that we use which was a suprise to me. I am good friends with a guy here in town that has diminshed lung capacity and one of the reason that he has gotten from doctors may be the years and years (15+) that he has been exposed to DE powder without really doing anything to protect himself. If you get alot of DE powder on your skin and it gets rubbed in or it is a while before you can wash it off it leaves your skin feeling like it has been lightly sanded by very fine sand paper. I know that anything that does that to my rough skin would do havok inside my lungs over time. I know that alot of the stuff that I use is bad mojo. I could blow myself up or choline gas myself but I guess it is the thought of coming on here in a few years and telling everyone that my lungs are fried.
Aardvark
Let us know how that works. I mixed several different samples because I wasn't sure what the right amount or DE to epoxy should be. I know that most G10 it is 65% glass filler and the rest epoxy, so I mixed from still thin and runny to almost a paste. I would love to be able to make a mold and use this mix to make something that could pass for bone and/or horn. I have some liquid rubber that I can use to make a mold if we can come up with the proper mix. Pre made handles would be great. Thanks everyone. mark
Some of my fears of DE may just be in my head I suppose. There is a couple of reason that I dislike it as much as I do. The warnings that are on the pacage are part of it. The "safety training" that I got when I worked at a pool store covered DE as much as it did several of the other explosive/poison chemicals that we use which was a suprise to me. I am good friends with a guy here in town that has diminshed lung capacity and one of the reason that he has gotten from doctors may be the years and years (15+) that he has been exposed to DE powder without really doing anything to protect himself. If you get alot of DE powder on your skin and it gets rubbed in or it is a while before you can wash it off it leaves your skin feeling like it has been lightly sanded by very fine sand paper. I know that anything that does that to my rough skin would do havok inside my lungs over time. I know that alot of the stuff that I use is bad mojo. I could blow myself up or choline gas myself but I guess it is the thought of coming on here in a few years and telling everyone that my lungs are fried.
Aardvark
Let us know how that works. I mixed several different samples because I wasn't sure what the right amount or DE to epoxy should be. I know that most G10 it is 65% glass filler and the rest epoxy, so I mixed from still thin and runny to almost a paste. I would love to be able to make a mold and use this mix to make something that could pass for bone and/or horn. I have some liquid rubber that I can use to make a mold if we can come up with the proper mix. Pre made handles would be great. Thanks everyone. mark
- Joined
- Mar 26, 2002
- Messages
- 3,397
mix another batch that is as thick with DE as you can manage.Mark Nelson said:
a very, very, very stiff paste.
check the durability,
then back off the %DE from that if needed.
Same if using wood flour or other filler.
You'll be surprised at how little epoxy volume
is needed for your purpose.