Working with Micarta

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angelfj1

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I am working on a project with parts composed of Micarta. Micarta is a phenolic resin impegnated fabric composite material with excellent electrical and mechanical properties. I am finding that it is very tough to saw, turn and mill. Inaddition when worked it exudes a strong chemical smell. Has anyone worked with this material and have any suggestions. Are the chemical odors dangerous?

Thanks
 
I don't know how dangerous it is but my rule of thumb is if it smells "chemical bad" it's probably best to use breathing protection. I do know the stuff is murder on cutting tools; I used up several saw blades cutting the green G-9 (epoxy glass) phenolic.
 
I have worked with it. It is obnoxious indeed. I had a dust collector at work that emptied its air outside the shop. That was quite useful to help with the smell. It dulls tools pretty efficiently too.

I have long legs and cannot get my steering wheel close enough to me to comfortably rest my elbow on the arm rest. Well,my motto is "A man who knows how to use a lathe and milling machine doesn't have to put up with too much crap!!!!" I made a linen impregnated steering wheel that stands off of my regular wheel about 4". Works perfectly and is removable for my little wife. Won't foul the air bag. They used the same stuff on the WWI Handley Page bomber steering wheel. Some knife makers seem to think it looks cool. Mine is dark brown,and does look cool on a steering wheel,but not on as knife handle,I think (nor does any other color of linen phenolic).

I have had this same wheel on my last few vans.

I made it from 1" thick sheet on a wood lathe at work,strictly on company time (that'll get back at them for making me get up and drive to work!!). I took a 1" end mill,and presented a flat bar of 01 to it at an upward angle in the vise. Hardened and drew it. It was a bit of a task,punctuated by having to re sharpen the chisel(I ground flat on its face to do so). I'd mounted the disc of phenolic on a plywood disc,screwed to the face plate,cutting through half of it with the disc,to correspond with the diameter of the van's wheel. I have no recollection of how I got it to perfectly register when I had to turn it over,but did so. This was all done freehand,like regular wood turning. I can't recall why I didn't use the big metal lathe. It had a vacuum hose,too,for sucking up cutting oil smoke(not the actual oil or hot chips!) Gosh !,I really had that place nailed for vacuum equipment!! I have COPD and don't want to breathe any more dust.

A ton of stinking yellow dust was made,mostly going up the 4" vac. hose. It made a wheel that looks like it was supplied by some medical supply house,or something. No one has ever questioned it during car inspections. They think it's legal,apparently,and professionally made!! Well,it WAS. I was a PAID toolmaker.


As to the question: I don't think breathing the stuff is the best idea. It just smells toxic,though I have no idea WHAT is released in smell. I think formaldehyde was used in making it. Could be wrong. Easily Googled. A sort of related plastic for eating plates and cups was made of UREA- urine and formaldehyde. HOW NICE!! We have all eaten off of it in cafeterias,I'm sure. Certainly in schools.

The wood lathe's minimum speed was 500 RPM. No doubt a slower speed,especially for that large diameter would have been helpful. I should have used the big metal lathe.
 
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If the material has a glass fiber in its construction then a diamond blade is best for cutting and shaping it--It can be turned with carbide tipped tools but they will need resharpening often--same as fiberglass products---hss just won't cut it effectively.--and yes don't breathe the vapors
 
Cured epoxy is generally non-toxic and most actually food safe. The problem is the particulates when cutting. Before curing, exposure to epoxies can generate an allergic sensitivity which can increase over time or suddenly appear which can be as bad as if they were toxic.

Most fiber composites can be problems for cutting. That toughness is one of the main reason for using them. Sometimes you just have to accept it and switch over to abrasives.
 
Epoxy is generally not bad (barring the dust, particulates in the lungs are generally not healthy), but it sounds like he is using a material with a phenolic binder. I have used a similar material with a linen cloth, rather than glass, and yes, it stinks. The smell (if I recall correctly), is mostly formaldehyde which comes from the breakdown of the phenolic material. Not the best to breath. I did whatever work I could outdoors, and wore a dust mask always. Wet sanding to finish isn't too bad (at least for the linen based stuff).
 
You could save money by becoming the first self embalming machinist.
 
There's no glass in Micarta. It is linen fibered material. I have machined a lot of it, and always used coolant. Never really noticed much of a smell, but it was not in a confined area like may be found in a small shop. If in doubt, always use PPE, and ventilate the area. If you do not or cannot use flood coolant, a mist system will help with any airborne particulate matter. Fumes will still be there, so exhausting them is the best idea.
 
Tony Wells said:
There's no glass in Micarta. It is linen fibered material. I have machined a lot of it, and always used coolant. Never really noticed much of a smell, but it was not in a confined area like may be found in a small shop. If in doubt, always use PPE, and ventilate the area. If you do not or cannot use flood coolant, a mist system will help with any airborne particulate matter. Fumes will still be there, so exhausting them is the best idea.
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Micarta comes in glass fiber, linen fiber, paper base, and wood base. The fiberglass is particularly irritating. Micarta also is not epoxy based. it is a thermal setting phenol resin. A plastic that is hardened by heat, not by a chemical reaction of two parts like epoxy. Both the parts phenol and formaldahyde are seriously dangerous chemicals. breathing fumes from burning micarta is really bad. As long as you do not get it hot that is not a real problem. But the dust is misserable. and hard to avoid breathing, and wearing. I hate the stuff and as an electrician it is a common material to work with. Electrical Micarta is almost always fiberglass impregnated.
 
I was referring only to the original Micarta developed by Westinghouse in the 1910 era. There was no epoxy or fiberglass in existence at the time. It was phenolic and linen, or a Bakelite version. Less common. There are variations now, of course. Generally they are known by their trade names.

Ref http://reference.insulators.info/publications/view/?id=12982
 
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