On Grinding - Dry Vs. Wet

Re: Safety III

david weaver

Fortunately for me, no MRI. AGH (the local ER for me) has a special room in their ER that's just for eyes, and they illuminated my eye with some swiss piece of equipment just to make sure the metal you could see on the surface was all there was to it.

Strangely enough, they hardly charged anything and aside from having my pupils dilated for quite some time (the ER doc litearlly picked the piece of metal off after the docs had a consult, since it wasn't in deep), there wasn't a lot to it. I could still see well, just literally saw the piece of metal as a slight blurred spot - literally a piece of frass off the sander at must've barely landed on the top and barely not been something that would've just washed off.

There were a couple of welders in there at the same time as me (11pm on a monday night) and their evening wasn't quite so pleasant as mine. I knew my issue was superficial, but I knew enough not to let it rust overnight, either.

I've pretty much unloaded my thoughts on this thread, but thinking about how I always stand off to the side of a wheel, I think I'll start yelling "clear prop!" from now on.

Re: Safety... c'mon, lets keep it in perspective h

david weaver

Wonder what the size of those flying grinding wheels was. There's not enough data there to tell, but I'm going to assume that they weren't garden variety 6" bench grinder wheels.

Guess it seems like good sense to keep fingers away from a grinding wheel and a pinch point, but apparently lots of folks don't think so!!

I've never met a woodworker who was injured by a grinder, though. First woodworker I ever met was missing the end of one of his fingers from a hobby jointer, though. One of those goofy non-adjustable craftsman things.

I did know lots of guys missing fingers or parts of fingers, etc, but they were all farmers and the reasons were all farm related.

But in the spirit of those osha reports, I'll do what I mentioned below "clear prop!"

Re: Safety... c'mon, lets keep it in perspective h

Tom

"In all seriousness, what do you guys think the risk is - statistically - of grinding a couple of plane irons and chisels per week. Honestly. Aluminum oxide contains very little to no free silica."

That isn't the question for the person who has never used one. In my experience the risk of picking up entirely new processes, even with all the info we have today, is pretty high. So easy when you know how, but your original post is not at the margin. It wasn't why would anyone who had both systems and 30 years of mastery under their belt prefer one over the other.

"Especially when you're already working with something that creates wood dust (even working by hand will create some dust, I don't know if you guys work by hand entirely on any reasonably large products and eschew sanding)."

The dangers are cumulative not concurrent. In some cases doing two things creates susceptibilities to even worse damage, though I know of no specific instance in this case.

"I'm sure there are some fines in the air from grinders, but I haven't cleaned around my grinder in a year, and all of the fines have pretty much settled straight down under the grinder (most of them end up in the guard, anyway). We are not talking about sprayed lacquer that stays in the air for a long time as a fog. "

I do grind in the shop, and am not so terribly happy about it. I normally assume stuff like turning on vacs, air management, etc... stirs all this stuff up again. Again, you are OK with it. Some people eat foot long hot dogs while smoking a cigar and drinking moonshine. Other people wear hemp and eat tofu, and juice grass (yumm). It takes all kinds. I'm sure you have read how long the grinders in Sheffield lived. It's better to be an Iraqui fighter pilot, ok, maybe not... Obviously huge exposure for the few months they lived. Failed to convince me it was a healthy lifestyle. We have people these days, who manage near pro levels of production, or time in shop, in tiny stagnent space, like a garage. Even though it is a hobby, they will get significant lifetime exposure to many processes.

Re: Safety... c'mon, lets keep it in perspective h *LINK*

wilbur

"The dangers are cumulative not concurrent. In some cases doing two things creates susceptibilities to even worse damage, though I know of no specific instance in this case."

Exactly. And even if the statistical chance of lung damage from dry wheel grinding is low, if it happens to you, it's a really crappy situation, and not one that I'm willing to trade a few extra minutes of work at a Tormek for.

The health risks of grinding with a dry wheel have been recognized since at least the 1860's. The source is linked below.


Health issues from grinding, Sheffield, 1866

Re: Safety... c'mon, lets keep it in perspective h

david weaver

Grinders in sheffield or cutlers in france and us in the shop grinding something once or twice per shop session are not similar. That's sort of like saying brushing off a dry natural stone makes us like the stone cutters in japanese mines (who also didn't live long).

I don't generally vacuum my aluminum oxide dust (thus the comment about most of it being in a pile under my grinder - actually when I do clean stuff like that up, I usually clean it up with a broom and dust pan), but in the event that I do vacuum any that has settled around the shop, the amount of dust suspended in the air, I would assume is very little. I'm open to being proven otherwise.

What I do in my shop that I think is worth caution is spraying waterborne lacquers. I do that in my shop with an OV mask only, and nobody else is allowed in it when I do. 15 minutes after the last coat of lacquer (which is about when it's dry enough that bugs don't stick to any of it), the door to the shop stays open for a while. I have much more concern about finishes than grinding. Even something as simple as everclear is not healthy to breathe.

Re: Not the only way *LINK*

Wiley Horne--So. Calif.

Speaking of grinding Japanese tools, I've attached below some instructions by Dick Fine Tools in Germany. I like to Tormek grind my Japanese user chisels and plane irons (meaning anything that's not going to be sold at some later date in new, unsharpened condition).

For me, the issue is not avoiding bluing or browning the iron; it's the transient heat created at the edge taking a point of RC away from how the smith made it. Take a look at the tempering graphs and grinding instructions for white and blue steel (courtesy Yasugi) at the bottom of the Dick article. Some of the better smiths will temper to 180C, leaving RC at approx. 63.5.

Yes, one can with care dry grind high-RC Japanese steel. There are those who can and do. But for me personally, I'd rather not think about heat transients at the edge of the steel. Each can make their own decision on this, but here's an advisory that quotes facts.

Wiley


Yasugi steel (courtesy of Dick Fine Tools)

Re: Safety... c'mon, lets keep it in perspective h

david weaver

We would be able to find data on hobbyists with lung ailments and who were non-smokers. If we avoid a dry grinder to touch up a bevel, we are on the outer edge of anything that would be statistically supportable, and we probably should stay away from things like cars, lawn mowers, stairs, bath tubs, etc at that point and maybe live in a rubber house that has no walls or doors.

I *have* met people who have become sensitized to wood dust (I don't mean on the forums, I mean in real life). We had a toy carver in my town when I was a kid, he worked for almost nothing because he wanted to give everyone a good deal and eventually he was sensitized to pine sap. He moved to walnut after that and eventually quit completely and died (don't know what he died from).

In general, though, my background (actuary) makes me avoid being extreme in a statistical sense. I always like to tell my friends (who always "know" what's going to kill them), "you can worry about as many things as many morbid or mortal things as you want to, but unless you're morbidly obese or already terminal, your chances of worrying about the right thing aren't very good".

(my wife, who is in health care, doesn't appreciate this commentary, as she likes to freely worry about possible terminal things without being bothered with the chances of whether or not the worry is in waste)

Re: Not the only way

david weaver

Hopefully, the design of the tool makes grinding on japanese tools very infrequent.

I do have a funjii plane that I've ground into a jack profile, though, and I freely grind it with a belt grinder. Works very well. I'm sure it wasn't that hard to start, though.

I would never put my mosaku on a grinder. Not because I think it would be unusable, but I couldn't bear that garish hollow on such a fine looking iron.

The blue tsunesaburo laminated bench plane irons grind so fast I don't notice very much heat. That's sheer laziness on my part, though, they are easy to grind by hand because there's very little hardened steel to the whole assembly.

yeah, the word was perspective...

John in NM

Whatever, I'm not much interested in changing your mind or getting into a big spitting match over this. I'm more interested in presenting a dissenting view for any who agree that grinders are fairly tame compared to a number of other machines we use with greater frequency.

You may think that your painting such a dire picture is appropriate, or even accurate. I simply do not agree because that picture is contrary to my experience and I think contrary to the experiences of many other woodworkers (not metalworkers, woodworkers).

Yeah... whatever...

John in NM

Hook it up to a dust collector or vacuum if it bothers you. Millions are not bothered by this dust for every individual who is.

I've nothing against wet grinders, use 'em if you like them. I just have very little patience (as you will no doubt have noticed already ) with the invention of safety boogie men used to cow impressionable newbies.

But whatever. As I just said to Tom, I'm not really angling to convince those who preach that we should live in terror of our bench grinders, I'm angling for those who might follow that advice

The truth is that these tools are not especially hazardous in a shop where all we do is sharpen a few steel chisels. Even if no one listens, I prefer the truth and will likely say so.

What would you bet...

John in NM

With all that worrying, it's some kind of stress related ailment that gets 'em in the end

Re: Safety... c'mon, lets keep it in perspective h

wilbur

One could make the same argument about the statistical risk form lung disease from the inhalation of ethanol and the actual exposure if you are a hobbyist as you made about my concerns about inhaling grinder wheel and metal dust, which just goes to show that we all have our individual things that we are worried about.

For me, the difference is that there is an alternative to dry grinding that provides an acceptable solution to my concern, whereas there doesn't seem to be an alternative that I can think of to using shellac and ethanol as a solvent. Besides, the lung damage from inhaling ethanol fumes, should that happen, will be milder and have a better chance of reversal than the lung damage from grinder wheel and metal particles, should that happen.

Statistics are good for analyzing populations, but they do very little to inform individual decision making. Individual decision making is more of a pro/con analysis, which varies from individual to individual depending on what their priorities are. I tell my patients that the risk of their kid getting an infection from another kid because chemo suppressed their immune system is so nonexistent that their kid should go to school whenever they can. Some of my families pull their kid out of school and home school them anyway. I don't argue with them. I just tell them that they can't say that it was my idea.

Re: Safety... c'mon, lets keep it in perspective h

david weaver

Sure. I won't stop using shellac for that - i don't even use designer ethanols, nor briwax for that matter even though there's nothing good about it for our brains, etc. I was just using that as an example of the multitude of small risks that exist, and justification of avoiding them all can create strange issues - like lack of enjoyment of life, or avoidance of physical activity, etc.

In all likelihood, our exposure isn't great enough to warrant that kind of concern. I am not a doctor, so that's a guess (besides, as an actuary, most of my answers begin with "chances are" or something similar like "in all likelihood").

I have two levels of caution, one when making babies, and the "other" when not. The "other" doesn't have too many restrictions aside from avoiding acutely dangerous activities and not doing things like sitting in a solvent vapor filled room for a long time.

At any rate, I've always liked my dermatologists suggestion for risk. She always says that she's not going to tell her patients to stay out of the sun entirely, because they won't do it. Instead, her advice is "if you're going to be in the sun, make sure you're doing something that makes it worth being there and not just waisting time absorbing radiation" (e.g., be exercising, spending time with family at a picnic, play golf, etc). I figure woodworking and just about everything is the same.

Re: Safety... c'mon, lets keep it in perspective h

cstanford

But don't kids get sick from being around other kids, period? I remember when we told our pediatrician that our daughter was going to start going to a mother's day out program a couple of times a week at our church. She said, 'get ready for her to pick up colds and other stuff.' She did, as if on cue. She'd hardly had anything before then since my wife was a stay at home mother - the baby had never gone to day care or anything like that.

I can easily see where a parent of a child being treated for cancer wouldn't want them to pick up stomach bugs and colds, etc., normal kid stuff, even if the risk were statistically (there's that word again) no greater than that of a well child getting sick, which of course even they do. Essentially, it's not a matter of if but when isn't it? As if the cancer weren't enough and all....

So, even if a cancer patient got sick at a rate no greater than the rate of the 'healthy' population that means they'll likely still get sick (all kids who go to school do). Would a patient on the kind of drugs you're talking about recover as quickly and with same risk of complications as the general population or is the risk of complications higher?

Re: Safety... c'mon, lets keep it in perspective h

wilbur

There was a point in time that if a kid was on chemotherapy, they were advised to stay away from other people because of the risk of infection. That meant no school, no play dates, no church, no going to the mall or the movies, and wearing masks when they had to go out. Over time, we started letting up on those restrictions, and the rate of infections in kids on chemotherapy did not change, which shows that those precautions did nothing other than to make life miserable for the kid and his/her family.

The reason for this is that the immunosuppression that comes with being on chemotherapy is in the form of a lowered white blood cell count. The risk of having a low WBC is a higher chance of a bacterial (not viral) infection when you develop a fever without a great way to fight it off.

The thing that wasn't realized was that the WBC is a secondary line of defense when it comes to your immune system, and has little to do with preventing bugs from other people from getting into your body. The parts of your immune system that are the first line of defense and that form a barrier to entry are your skin, nose hairs, mucus, cilia in the respiratory tree, and the lining of the GI tract. Those things all work even if your WBC is zero.

In addition, when bacterial infections are found in kids on chemo with a fever and low WBC, they are bacteria that can be traced back to bugs that grow on your own skin and GI tract. There is no reasonable way to clear out those bacteria.

My advice to my families whose kid is on chemo is that if they are wondering whether doing something will put their kid at risk for infection, pretend like the cancer and chemo never happened. If a trip to the mall didn't worry them before about their kid catching an infection, then go to the mall. If they had a play date scheduled with a friend, and they get a call from the other mom that the friend has diarrhea, then don't go. But that's not because the kid is on chemo. That's because no one should go to a house where a kid is in the middle of having diarrhea.

The speed at which a kid is going to recover from these infections somewhat depends on the WBC recovery for bacterial (not viral) infections. But since bacterial infections are sourced from the kid himself, the exposure from other kids is a non-issue as far as I'm concerned.

Again, a small percentage of my families do put their kid in a bubble. I don't argue with them about that, because if doing that will help them sleep at night, that's fine with me. I just tell them that they can't tell their friends that doing so was my idea.

Re: Safety... c'mon, lets keep it in perspective h

Charles Stanford

I guess my point is that kids get sick. They just do. If cancer patients on chemotherapy recover as quickly without greater risk for complications then it's a non-issue. Seems to defy common sense but if that's the case then that's the case. Is that what you're saying?

Re: Safety... c'mon, lets keep it in perspective h

Charles Stanford

Probably too simplistic:

http://www.cdc.gov/features/PreventInfections/

We unfortunately have a cancer patient in our family, though not a pediatric cancer patient, and this issue has come up. I'm not picking at you. Just amazed at how advice seems to vary across the medical community.

Re: Safety... c'mon, lets keep it in perspective h

david weaver

There is no advice in that bulletin that disagrees with what Wilbur says.

It says that if you have a fever, it might be an infection, and it describes ways to avoid getting infections.

It also says you're more likely to get infections from everyday activities (as a chemo patient), but it doesn't describe those as activities that occur (only) if you leave the house.

You stand to make a fool of yourself if you argue with Wilbur about this stuff, and while wilbur wouldn't probably say that someone probably should say it on his behalf so that you don't waste his time when it's extremely unlikely that wilbur relies on local tribal data that varies from place to place. Arguing with wilbur about medicine is probably a lot like arguing with George about craftsmanship.

Re: Safety... c'mon, lets keep it in perspective h

david weaver

>>That's because no one should go to a house where a kid is in the middle of having diarrhea<<

Maybe it's because I grew up the descendant of farmers where toilet humor was always in bounds, but I so would love to make a Jack Handey style quote out of that (of course, credit would be given to Wilbur).

Re: Safety... c'mon, lets keep it in perspective h

wilbur

Yes, that's exactly what I'm saying. I'm not sure what part of "My advice to my families whose kid is on chemo is that if they are wondering whether doing something will put their kid at risk for infection, pretend like the cancer and chemo never happened," was unclear.

"Common sense" is the lowest level of justification for anything we do in medicine. It is always trumped by data and real outcomes. Common sense is what caused Aristotle to conclude that the liver must be the organ that produced blood, and that the heart was a minor player in circulating blood, partially because it was so much bigger than the heart.

The same thing could be said of many things we do in woodworking. It may be common sense that setting up a chipbreaker is too fussy of an operation to be useful, but when one's experience shows otherwise, the common sense explanation falls by the wayside.