epoxy ??????

[Sunbeam]

Like you, I find that a cartridge respirator is comfortable, but I also have the problem that the paper-type masks don't fit my face very well, and thus let stuff in around the sides. I should probably wear my respirator with just the pink cartridges more often (I get in the habit of leaving the other ones on, but it's considerably heavier that way).

When spraying most 2 part paints(containing hardener) a full face mask is required

Side note: I've always understood that an actual "supplied air" respirator was needed (and not just a regular, full-face one) for spraying a two-part paint such as an LPU.

 

[mgarr682]

Mike comments: " JB Weld works well for this on motorcycles (don't ask) but I'd hesitate to use it in a marine application since I don't know what filler they use. " I don't know what filler they use, but it does not seem to corrode or "rust". I have used it on the lower unit of a 25 hp outboard which collided with a uncharted rock....and it was still in good shape after about 3 years. A friend had an aluminum block/ water passage 6-71 repaired with J B weld by the head mechanic at Trade Tech in Los Angeles--he felt that hot salt water and the aluminum were fine. I only followed that repair for about 7 years, but it was still working well. It is certainly in my bag which I carry on the boat. They have "wood" & "Plastic" now. I have used both of these in repairs.

That's good to know. I've carried JB Weld in my motorcycle tool kit for years (for uncharted rocks, I can't resist a dirt road in the mountains and have needed it more than once). I think I'll add some to the boat tool kit.

 

[thataway]

As for respirators: If you are just doing light sanding or using particulates the surgical mask is fine--be sure you have a good face fit as SunBeam notes--there are different brands and types--some are better than others.

If you go to Full OSHA standards--yes, full face with external air source is required in many spray conditions.

However there are many boat yard workers who have been using the simple face mask respirators for all of their lives and do not seem to have to come to any harm. If you are in spray booth--definately the external air--should be no exceptions in today's world.

I have sprayed LP with just the simple mask--and it seems to be fine. But I have only sprayed it a few times. One has to look at the costs of the machinery etc. Again--the several time use--vs industrial and "overkill".

Something else not mentioned is the use of Tyvek suits and hoods. If I am doing any serious sanding, grinding or painting I put one on. They are cheap and disposable. I would put these as essential for anyone more than the casual hobby user.

Another clue is to use "GoJo" Citrius cleaner. I keep a couple of gallons around the clean up area, for both my hands and any tools etc. It is much better for you than using lacquer thinner. Also you should avoid cleaning with alcohol or petroleum base before using epoxy. Use a commercial degreasing solvent. Acetone or MEK is commonly used. Trichloroethylene is excellent but far more toxic--and used in more industrial settings. (respirator and skin protection should be provided), rarely by the hobby user.

 

[Sunbeam]

Something else not mentioned is the use of Tyvek suits and hoods. If I am doing any serious sanding, grinding or painting I put one on. They are cheap and disposable. I would put these as essential for anyone more than the casual hobby user.

Good catch! Back in the beginning of the thread I thought about mentioning them, but in my first post I was specifically responding to Roger, and I think he's a farmer, so I was picturing him probably laughing at the idea of buying a suit when he probably has tons of old work clothes I do like the Tyvek suits though and always wear one when I'm into epoxy/paint/etc.

Also you should avoid cleaning with alcohol ... before using epoxy. Use a commercial degreasing solvent. Acetone or MEK is commonly used.

Oh boy, this is news to me. I do use Interlux Solvent Wash 202 to first clean anything that might have mold release wax or other similar contaminants, but my usual cleaning solvent (and sometimes only one) is denatured alcohol. I use it before all of my epoxy jobs (the only time I don't use it is prior to polyurethane sealant). So this is a no-no? Why is that?

(I used to use acetone more, but switched to alcohol because I had such a hard time finding good gloves that will keep it off my skin - it is so drying. I got the idea from a yard. Not that acetone doesn't do a fine job though and I do still have it around for certain situations.)

Sunbeam

PS: This scared me enough (since I'm just about to go lay in some epoxy after earlier prepping with alcohol :shock that I had to do a quick check. I only have a few minutes, as I need to get back to my epoxying before evening sets in, but I did see that in several places WEST's instructions said to clean with alcohol prior to epoxying. I only looked at the short bit of text that was in the Google "hits," so I may be missing something still, but it was mentioned to wipe out blisters "divots" after grinding them and just before epoxying them with generous amounts of alcohol, and also is included in some of their repair kits (in the form of small alcohol wipes). I also see where MAS epoxies recommend prepping with alcohol. I think I'm comfortable enough to go back outside and finish up, but I would like to know more about why you don't recommend it though, as I know you know your stuff.

 

[thataway]

The reason that alcohol is not recommended is that it is often cut with water. If it is pure alcohol, then that is fine. For example isopropyl alcohol which you buy will be 70% or 90%--the rest water. You want to be sure that there is no water on the surface.

 

[Sunbeam]

Okay thanks. I use denatured alcohol that comes in one of those flat cans (probably a quart?). I'll take a look at it tomorrow when I'm on the boat.

Sunbeam

 

[thataway]

Denatured alcohol is usually 90% ethanol--usually with methanol thrown in, but it can be any number of other "poisons". The biggest problem is isopropyl which many folks use since it is so cheap--and almost always cut.

I cannot comment on Roger's farm or dirty clothes. (A PM about farms), but the Tyvek is a good protectant from dust, fiber, particles etc which may get on or into the skin. I prefer not to get particles embedded in the clothes.

 

[Sunbeam]

I cannot comment on Roger's farm or dirty clothes. (A PM about farms), but the Tyvek is a good protectant from dust, fiber, particles etc which may get on or into the skin. I prefer not to get particles embedded in the clothes.

I thought I said "old" or "work" clothes? At any rate, not implying that Roger has poor laundry habits! I absolutely should have mentioned the Tyvek suits, as I agree with you that they are a great way to go. I have cotton work coveralls that I always wear, but I still put hooded Tyvek on over them for any epoxy jobs. I even tape the first pair of nitrile gloves to the cuffs of the suit, because before I did that I would invariably stretch or reach and get epoxy on that one sliver of exposed skin on my wrist :amgry

 

[PeterQ]

Very interesting tech thread! There's also a good article in the April/May 2013 issue of Boat/US Magazine on page 88 about re-bedding with epoxy and sealants. It also has big color pictures to boot! There's a general discussion of sealants on page 80 as well....

Their recommendations seem to mirror what's been covered C-Brats....anyone care to comment on the articles?

Pete

P.S. I have a CD25 on order and want to get smarter - y'all are a tremendous resource!