Safety guy question: chemical fumes
 

Ok, I have to varnish about 600 sq ft of floor in my house with oil-based polyurethane, in rooms that will be sealed in plastic in order to keep dust off the varnish. Needless to say, it's going to get pretty stinky in there. Can a cartridge element-type respirator be used, or do I have to go with some sort of air supply? If an air supply is used, does anyone make a kit that fits onto a shop air compressor ? Any advice is appreciated!

Cartridge element type filters could be used but it depends on the type. Check with suppliers' specifications.

The military use canisters, for example, for chemical warfare situations - if I remember rightly they are carbon based... The length of a canister's life span is related to the density or concentration of the fumes. The better you can ventilate your working area the better it will be for you. However blowing lots of air over a newly varnished floor will probably encourage dust to settle on your nice smooth surface.

I'd be wary about using a standard air compressor for breathing air. Atomised oil will be present in this air - I guess that will be carcinogenic

Organic vapor cartridge would be the one required, I think they are black labelled. Can't use a compressor for breathing air, a set-up that's OSHA approved would be too expensive. You do need to ventilate though, set up a fan to suck the fumes out and a filter (a furnace filter or 3) setup to keep the dust down on the air intake side. The limitations of respirator cartridges are directly related to the concentration of contaminents. If you smell the vapor through the respirator, the cartridge is 'full' and must be replaced.
Good luck

i think the standard binks double respirator cartridge would probably suffice; if you're working more than four or five hours, spend the money and get an extra set of charcoal filters (and change them out about halfway through). also, a cheap box fan, clean and new ($20, maybe) set to suck out, will certainly help.

(this is a solvent based product? single stage of two stage?)

It's single stage solvent based. It's going to need about 5 coats, one every six hours according to Varthane's recommendations. Varthane claims this particular product (oil-based Floor Urethane "Diamond Professional") does not require sanding between coats, altho I will have to sand the initial Interlux sealer coat, so counting the sealer coat I'll have seven passes in all. I'll have three people brush painting 600 sq ft at a time on each pass. I suppose I could mount a fan in the window with air flow directed out, sealed up real good to keep any dust from floating back in, but I really thought I'd get the best finish if I kept dead air.

Just hire some illegals... they don't need no stinking respirator...:D:D

I would keep no air flow as well. With three people and 600 sq ft you won't be in there for too long on each coat. Good organic vapor respirators will be fine.

Biggest problem I think you are going to have is the extended beer break between coats, 5 hrs is a lotta drinkin' time:D maybe CLK man would like to help;)

I believe the organic vapor respirator would be sufficient. The only problem would be if you were in an Oxygen depleted atmosphere, but I do not believe that to be the case.
Monitoring the air would be good, but probably cost prohibitive--got any canaries?

Just beware the Glitza...:eek:

Hire a couple of illegals they won't complain about a little smell.:D

Hmmmm? I've finished lots of floors with that same Polyurethane and never used a respirator. How bad is the stuff? I typically put a fan in the window blowing out. Should be able to do one coat on 600sq ft in half an hour or so. They changed the formula a few years ago and now it takes much longer for each coat to dry before putting the next coat on. If the rooms are totally sealed I think it will take even longer to dry. Another reason to put a fan in a window blowing out.
I use leather mocassins when putting on coats after the first one. I found patterned soles on shoes would sometimes leaves marks on the floor. I use a foam applicator pad and keep it in a ziplock bag between coats.

Depending on the state of the floor after sanding. I think most proffessionals use a large squeegee and no brush except around the edges. It is very fast in comparison to brushing. Just spill and spread. Gravity does the rest.

Two coats by squeegy are good three are great . I have been putting off re doing the family room floor until I can find out if I can add finely ground aluminium oxide to the polyurathane base finish. I have not checked out the possibility of this yet properly.

i would look into a lambskin applicator or the afore-mentioned foam applicator. (personally, i prefer lambskin over synthetic... except for ... well, you know. :D)

Thanks for all the good advice.

I've never done a squeegee thing, but it sounds to me like it would leave marks. I've read a number of things which recommend a badger-hair brush application for the best finish.

Here's some more good info regarding respirator ratings:

http://www.cdc.gov/niosh/npptl/topics/respirators/factsheets/respfact.html

http://www.lni.wa.gov/wisha/rules/respirators/PDFs/HT3-Resources.pdf

I use a magenta color coded, P-100 respirator for car paint, a substance that I believe is far nastier than polyurethane and I can detect no odor whatsoever in an area full of the vapors.

As for finishing, I did 2 areas of cork flooring. The first one using a lambs wool pad and the second using a 3/16 knap mohair roller. Several years later, the area finished with the lambs wool is still showing streaks and "brush marks" while the area finished with the roller is perfectly smooth.

I have been using solvent chemicals in my printing business for years. The safety sheet said to wear gloves. I never have. Those chemicals can cause Dain Bramage and severe studdering. I da da da da do do do don't sta sta sta sta der, do I? :eek: