Metaluna

I'm going to be cutting a CF steerer soon, and I plan to use a Dremel w/ diamond cut-off wheel, which I understand generates a lot of very fine dust. The best dust masks I can find locally are N95 rated. I know there's a grade above this (N100) but I'd have to order one and it may not get here in time. Will N95 be good enough? I've seen places advertising N95's for protection against airborne viruses, so I have to believe it will be pretty good against a few minutes of exposure to CF dust.

Metzinger

Dremels are good at creating lots of dust. A good hacksaw with a fine toothed blade is ideal.
Here's some advice.

phoebeisis

That mask should work fine.I suspect that the CF dust isn't that big a deal.The dust from the cut off wheels might have been a bigger health concerns when/if it had silica like material in it.

A hacksaw with a fine tooth blade will produce coarse "dust" which is no problem. In general the finer the dust, the more heath concern it is. Hacksaw might give a straighter cut also.I doubt you need a mask for hacksaw use.

Charlie

davidad

It might be a better idea to cut it with a fine bleded hack saw and clean up the cut with a file or emery cloth.
If the dust is harmful then a face mask with HEPA type filters as is used in asbestoes abatement would be better.

DMF 

Yeah, don't use one of those surgical type masks that don't seal completely. Use a cartridge-type respirator mask with a rubber face seal and at least two head straps to hold it in position. Full-face would be even better, but those aren't common. And protect your eyes, too.

DieselDan

If possible, have fan blowing from behind you to keep dust offf of you. I had a shop that could be cross ventilated with both a push and suction fan.

frankenmike 

Full body biohazard suit, taped at the seams, with at least a HEPA filter and electrostatic matrix. Seriously, bro, just go outside and cut it. Unless you do this for a living(i.e. every day) you'll be fine.

rm -rf

A hacksaw will be much easier than a dremel cutoff wheel, which will tend to get trapped in the cut as you go around.

I cut a carbon seatpost, and it was fast and easy with a hacksaw.

Al1943

I use a hose clamp, fine tooth hacksaw, and then square and smooth the end with a file.

Al

HillRider

I've cut three carbon steerers using a fine blade (32tpi) hacksaw and the results have been excellent and the dust minimal. A hacksaw using a stainless hoseclamp as a cutting guide is much easier to control and generates less dust and heat than any Dremel. As noted, do it outside with a hacksaw and relax. Use a dust mask if you wish but it's a precaution more than a necessity.

ScrubJ

This

BCRider

Hand tools for the win. Just say no to power tool options in this case. The fine tooth hacksaw is jsut so much easier, quieter and if you go slow the dust will politely fall away from the blade to the floor or into some waiting container you place below the cut. No need for a mask at all. Same with the file or fine sandpaper to clean up the end. Just do your sanding or filing over your trash can and wipe away the dust instead of blowing it away. It'll all politely fall into the container.

JanMM

An N95 mask seals tightly, if it fits you, and protects against mycobacterium (TB) bad boys floating in the air. Maybe overkill for CF dust. But it is the mask of choice for playing with fiberglass insulation in the attic.

brucewiley

Hold your breath

Eprobungs

Submerge in water. Hacksaw.

merlin55

one way to avoid CF dust

wiliermdb

Use a hacksaw and a guide. I suggest investing in a steerer tube cutting guide for under $15. You mount it in a vise and you'll be finished with a clean and straight cut in under a minute. No dust to worry about, either. Beats having to file and hoping you get it straight. I'd never use a cutoff wheel on any tool to cut a steerer tube. Use the correct tool for the job. Once you're done, hit it lightly with some 1000 grit paper to knock the edge off.

Check out this link for the tool I use.

https://www.performancebike.com/bikes..._400005_400145

Metaluna

Thanks everyone. The more I read about CF dust thrown off from power tools, the more I want to keep it simple and just use the hacksaw approach. I do have a steerer cutting guide (the Nashbar one, probably the same as the Performance one), and some 32TPI blades, so I'll just do it the traditional way, with a dust mask for peace of mind.

HillRider

I also have the Performance (aka Nashbar) cutting guide and it works very well. I've even used it to shorten an aluminum seatpost for road bike use.

DaveSSS 

If I was that worried about a little dust, I'd place my shop vac nozzle real close to the cutting area. A hacksaw works fine. I've never even used a cutting guide. I scribe a mark at the top of the 5mm spacer above the stem and cut just below that line. I make a shallow cut all around the outside first, rather than cutting from top to bottom. Deepen the cut as you go around a couple of times. The cut should be straight enough and there will be no frayed fibers.

Metzinger

Only do this if the cannister of the vacuum is in an uninhabited area that's sealed off from where you are working.
The ShopVac will exhaust the dust farther and quicker than even a Dremel could. That is, unless there's a way of creating an N99 filtration system for it. (There is not.)

This lesson I learned while attempting to vacuum up drywall dust.

nitropowered

32tpi hacksaw blade. If you are really worried, spray some soapy water on the tube so there is less dust floating around

roadfix

Are you going to be doing this everyday? If so, then I'd protect myself.

I don't use any protection as cutting CF for me is very infrequent. I have a better chance of developing something terminal from my daily consumption of diet coke.

ValVal

+1
i just can't help drinking this thing...

MilitantPotato

Yea, cause we all know one day of exposure to a particulate much like asbestos won't do any harm.