Dust Masks

[Jeremy Scuteri]

For a hand saw to be equivalent to a table saw in wood dust production, dispersion and mean particle size it would need to operate at a similar speed continuously. It's the multiple high speed collisions of the table saw blade teeth with shavings which makes the small particles. (Think mulching lawnmower blades) A handsaw produces negligible amounts of the <3 micron dust which travels deep into our lungs and is the most harmful.

Here is a video of a tablesaw cutting wood in slow motion. (http://www.liveleak.com/view?i=e9d_1404960342&comments=1) I don't see this "mulching lawnmower blade" effect that you are referring to. It seems that each pass of a carbide tooth removes some stock and when you slow it way down you would never know if the blade was spinning at 60 RPM or 6000 RPM. Am I missing something here?

I definitely see how a power tool will propel any dust/chips that it creates further because of the high speed. I could also believe that the dust/chip size may be finer due to the relationship between "cuts per second of the blade" and feed rate, but that is not the same as the original statement of "hand tools don't create dust". Bill Pentz also disagrees with the statement that "Hand tools are safe when it comes to dust", but he might be a bit overzealous.

 

[Tarhead]

I agree that handtools make dust that can be inhaled and stick to the mucous layer from the nostrils down to the terminal airways deep in the lungs.
Does a handsaw make dust? Of course.
Does a handsaw make and disperse <3 micron wood dust? Not very much.
Do I wear a mask while using a hand saw? Yes on wood that I am bothered by but others no. Cherry bothers me (head stops up and nose drips, sore throat, coughing, wheezing).
On the video we can't see the <3 micron particles the teeth make by repeatedly hitting the larger chips but we know it is happening. That's the mulching mower blade effect. Look again and you will see the collisions.

 

[richlife]

I've used earbuds before to listen to music. I have found they are not as good as dedicated hearing protection but not bad. I would prefer to protect my ears in any way that is effective and get to listen to music which helps me think. Muff or plug....as long as the hearing is protected.

Zach, I'm not sure if your were referring to "earbuds" in response to "foam ear plugs" or not. They definitely are not similar. Ear buds would provide minimal protection and might have to be turned up loud enough to do their own damage. FWW did a study a number of years ago that showed that foam ear plugs actually reduce sound better than over-ear protection. That's why I prefer to just clean my ears when needed. (And I have wax producing ears that do require occasional cleaning. Otherwise, no need for plugs, head sets or whatever. I have been near deafened simply by collected ear wax accumulation before I found out about this.)

Rich

 

[SubGuy]

I lost my train of thought when I quoted you and was just talking about using them as they do reduce a noticeable amount of noise. You can try yourself with a Skull Candy style (or whatever fits your ear canal good) and not turn on the music. It will dampen somewhat. I just like hearing music when I work.

Zach, I'm not sure if your were referring to "earbuds" in response to "foam ear plugs" or not. They definitely are not similar. Ear buds would provide minimal protection and might have to be turned up loud enough to do their own damage. FWW did a study a number of years ago that showed that foam ear plugs actually reduce sound better than over-ear protection. That's why I prefer to just clean my ears when needed. (And I have wax producing ears that do require occasional cleaning. Otherwise, no need for plugs, head sets or whatever. I have been near deafened simply by collected ear wax accumulation before I found out about this.)

Rich