Knife Makers: Is sanding G-10 dangerous?

Diomedes Industries

Diomedes Industries

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Mar 19, 2007
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I have a liner lock folder kit that I am putting together and it comes with slightly over sized G-10 scales. I thought I had heard that you should not sand this inside because the dust was dangerous. Is this true? Should I do this with ventilation or a respirator - or is this just wrong?

TF
 
drywall respirator,and use 3m wet/dry autobody paper, and wet sand it. Wipe up slurry/dust with wet rag and seal in palstic bag for disposal.
 
Micarta, G-10, some woods and even steels should be worked using a high quality respirator. The epoxies in the Micarta and G-10 are dangerous, some exotic woods are poisonous, and some steels have heavy metals in them. Might find more info in the maker's forum....:thumbup:
 
Bushman - WOW - that bad huh - I will take care. I started to sand just a little and smelled those fumes and remembered the warning.


TF
 
G-10 is worse than Micarta because it has glass in it. You don't want glass imbedding into your lungs.
 
Tal,

I'm gonna move this to the knifemakers' area - you'll get a lot of soild asdvice there like Mark's here.
 
Getting a good respirator is definately a good thing. I wear it every time I cut, grind, file, and sand any material, not just G10. I got pretty grossed out after a day of grinding blades and I blew my nose, and it was all black. Since that day I never do anything that generates any kind of dust with anything unless I have my respirator on. I got the 3m 7500 half face and it is super cushy on the face, and no problems getting a good seal. The exhaust goes straight down so if you are wearing a full face shield for eye protection the shield will not fog up. check the links. One for the respirator, and another for the particulate filter elements. The last one is for when you are grinding stabilized wood cause they say it makes formaldehyde, and this one is a particulate and vapor filter too.


http://www.boss-safety.com/shop/7503-ultimate-half-facepiece-respirator-large-p-1875.html

http://www.boss-safety.com/shop/cartridges-filters-2091-filter-series-c-415_9_18_127_576.html

http://www.boss-safety.com/shop/60925-formaldehydeorganic-vaporp100-p-238.html
 
G10 is glass fabric held together with epoxy resin.
Once epoxies are cured they are not particularly toxic. They are mostly a dust hazard.
But the glass fibers are not good to breathe. They cut the lung lining. Bad juju.

If you use a repirator and a vacuum setup to control the dust you should be fine.
 
Knarfeng: You're right that epoxies are quite stable and inert... until you heat them up.
Micarta, G-10, Carbon Fiber, etc. are mostly based on a formaldehyde-phenol epoxy, and will give off formaldehyde vapors when you're grinding them. (Same deal with stabilized wood, as Gixxer says.) It's really a good idea to wear a respirator that's specifically designed for this kind of protection. I know that 3M has a special formaldehyde rating for some of their filters, like the one Gixxer uses. (Of course the glass and other fibers that have already been mentioned are just as much a concern. Carbon Fiber is supposed to be especially bad... I'm not going to test that one out for myself.)

Ilbruche, "Natural" products aren't any more or less safe than "artificial" ones—many hardwoods are quite toxic. Remember that every compound in the world is made from "chemicals," and just because it comes from the ground doesn't mean it's safe to grind up and inhale.

I don't wear a respirator when I'm hogging steel on a 30-80grit belt, under the assumption that those particles are too big to do much damage. I'm probably wrong about that... and if I was hogging out blades every day I'd wear some kind of protection the whole time.

Get a good respirator, and get some good shop ventilation! If you can work outside, do it!
 
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Hi Guys,

I spent years in the 70s and 80s making jewelry. I flushed my nose out every night. Who knows what I've done to myself.

Anyone got any more links or suggestions as to how I can get basic respirator orientation? I checked out the site links gixxer posted, but I need to know more in order to make an informed decision as regards which mask I should get. BTW, I have a beard. That makes it more difficult.

Also, I work with high school students and need an inexpensive, yet effective solution for them when their grinding.

Thanks, Phil
 
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JacksonKnives said:
Knarfeng: You're right that epoxies are quite stable and inert... until you heat them up.
Micarta, G-10, Carbon Fiber, etc. are mostly based on a formaldehyde-phenol epoxy, and will give off formaldehyde vapors when you're grinding them. (Same deal with stabilized wood, as Gixxer says.) It's really a good idea to wear a respirator that's specifically designed for this kind of protection. I know that 3M has a special formaldehyde rating for some of their filters, like the one Gixxer uses. (Of course the glass and other fibers that have already been mentioned are just as much a concern. Carbon Fiber is supposed to be especially bad... I'm not going to test that one out for myself.)
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Get a good respirator, and get some good shop ventilation! If you can work outside, do it!
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Your statement that I green highlighted is not true. Most epoxies used for G10 are based on bis-phenol A epoxy reacted with a dicarboxyllic acid. They do not emit formaldehyde upon thermal decomposition. They release mostly CO2 and CO. Also, I do not consider grinding to create the conditions necessary for actual thermal decomposition. The grinding process happens too fast.

Phenol formaldehyde resins are what are commonly called "phenolic" resins. If you were grinding phenolic micarta, you might be more worried about toxic biproducts such as you describe. However, as with G10 above, I do not consider grinding to create the conditions necessary for actual thermal decomposition. The grinding process happens too fast.

But I fully agree that a vacuum system to pull away the dust and whatever is a good thing. And I would be the last one to say you must not use a full respirator utilizing cartridges that absorb organics.
 
About those vaccum systems, make sure you are not sucking hot metal sparks into a bin or system of non-metal dust. You will be getting aquainted with the fine foks down at your local fire dept. Make sure you use a spark arrestor.
Phil, I went down to a local industrial supply store and found a mask that fit me best, and I have a beard also.
 
knarfeng said:
pwnage
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No kidding? And here I was thinking they were all phenolic.
Any good sources to figure out which are which? (My suppliers don't usually have a clue.) I know for certain that some of my Micarta is phenolic.
As far as heat/time required for decomposition... I'd rather not take the risk.
(Though I've eaten moldy cheese before... something about the shop makes me into a worry-wart.)
 
JacksonKnives said:
No kidding? And here I was thinking they were all phenolic.
Any good sources to figure out which are which? (My suppliers don't usually have a clue.) I know for certain that some of my Micarta is phenolic.
As far as heat/time required for decomposition... I'd rather not take the risk.
(Though I've eaten moldy cheese before... something about the shop makes me into a worry-wart.)
Click to expand...
I believe that the phenolics were utilized because of certain physical properties. As far as adhesives/resins go, things like polyester and vinylester are considered to be inferior to good old marine epoxy, but they cost a lot less so they are used extensively in boat building, particularly in non-stressed components. As far as G10 goes, formaldehyde or not, I would be worried about the glass fibers.
 
JacksonKnives said:
No kidding? And here I was thinking they were all phenolic.
Any good sources to figure out which are which? (My suppliers don't usually have a clue.) I know for certain that some of my Micarta is phenolic.
As far as heat/time required for decomposition... I'd rather not take the risk.
(Though I've eaten moldy cheese before... something about the shop makes me into a worry-wart.)
Click to expand...


There are so many variants in "micarta" that it is hard to tell the players without a scorecard. The resin variants with which I am familiar are phenolic, epoxy, and silicone. But I doubt you would get silicone resin based micarta sold to you for a knife handle. The silicone resins are used for high temp. Some of them will take 600-700°F and they are bloody expensive.

I doubt that I could tell just looking or feeling a piece of micarta whether it was made from epoxy or phenolic. I work with composite laminates(similar to G10, but made with graphite fabric instead of glass fabric), but I do not have much in the way of hands-on experience with micarta. Sorry I cannot be of more help.
 
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