epoxy ??????

thataway · Posted: Sun Mar 24, 2013 2:11 pm Post subject:

The full face masks and respirators are over kill for the dust of cabosil. I use the good 3 M surgeon type of mask.

I also think that maybe we are getting into a bit of overkill for filling a few holes in the transom.

Marine Tex is being left out--and if you want to just fill small holes and there is no wet substrait, I will use Marine Tex--I keep some on the boat, It is quick and easy, no big deal. If you have a serious project then Marine Tex (or similar types) are not the best way to go. Also fiberglass repair workers don't like Marine Tex because gel coat does not adhere well to it.

I also keep a couple of the squeeze bottles of the 5 minute epoxy by west systems to do the "wet out"--you squeeze equal parts--paint in in first, and then put in the MarineTex or what every you are going to use.

I also keep a gallon of West System Epoxy and several hardeners. Not mentioned is that you need to have the hardener appropriate for the temperature and working time.

I use nitrile gloves--far better than the latex, which will go bad.

I use yogurt cups for mixing. I don't like various paper cups--because they may have wax in them.

I love the Dremel tool and keep several around the shop--and at least one on the boat. This is easy to drill out and under cut.

For the larger projects, I prefer to use cabosil or fumed silica to start with, and as it thickens I add high density filler. I don't like the mill fibers,unless it is a deeper hole,and I need some structural intreguity--in most of those cases then I will be using glass cloth strands. Peanut better is about the right consistency. If right very little will run out.

I have not used the 610

Sunbeam · Posted: Sun Mar 24, 2013 2:20 pm Post subject:

thataway · Posted: Sun Mar 24, 2013 3:23 pm Post subject:

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.

Robert H. Wilkinson · Posted: Sun Mar 24, 2013 3:26 pm Post subject:

We use the 3M masks at work and I would say that for anybody needing them on a somewhat regular basis they are worth the expense. I find for dust the p100(pink) cartridge is easier to breath than with a surgical type mask. With their one way valve they are quit comfortable and light.

The organic cartridges contain activated charcoal and when not in use should be stored in a large ziplock freezer bag. As Sunbeam said they need to be protected(sealed) when stored so the charcoal does not continue to soak up and wear out when not being used.

When spraying most 2 part paints(containing hardener) a full face mask is required as well as covering any exposed skin.

Regards, Rob

Sunbeam · Posted: Sun Mar 24, 2013 3:37 pm Post subject:

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).

mgarr682 · Posted: Sun Mar 24, 2013 4:07 pm Post subject:

thataway · Posted: Sun Mar 24, 2013 5:52 pm Post subject:

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 · Posted: Sun Mar 24, 2013 6:30 pm Post subject:

thataway · Posted: Sun Mar 24, 2013 9:42 pm Post subject:

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 · Posted: Sun Mar 24, 2013 10:09 pm Post subject:

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 · Posted: Sun Mar 24, 2013 10:41 pm Post subject:

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 · Posted: Sun Mar 24, 2013 10:55 pm Post subject:

PeterQ · Posted: Mon Mar 25, 2013 11:15 am Post subject:

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!

Very Happy