Removing Epoxy Sanding Dust

[ealger]

I'm about to put a 4th epoxy coat on my Ranger after having sanded to remove surface junk collected on my 3rd coat and to finish up the stem bias tape area.
Vacuuming removes the surface dust but the static build up from vacuuming attracts everything in sight!

What's suggested prior to applying the "lastcoat" of epoxy?
Leave it alone and apply, tacking with some sort of solvent??
ed..

[Glen Smith]

I clean off the epoxy dust with a clean rag and warm water, dry with paper towels. Solvents cause a buildup of static and should be avoided.

[ealger]

Ah, thanks Glen. Sounds like the thing to do. I'll give it a try.
Ed..

[Larebow]

Glen is one smart cookie helped me out a lot!!

Do tou guys think one of those swiffer sweeper pads would eork? It's suppose to be residue free (no chemicals)Works on a negative carge to get everthing to stick to it,works awesome on pet hair.

[Jim Dodd]

Hi Ed
A trick I learned about applying several epoxy coats is, put the first wet out coat on, let it cure,or almost cure, typically 4 hours, or more.
Then apply the second coat.
While the second coat is still in the tacky stage, 2 to 3 hours, apply the third coat, and so on.
The tackinees will keep the next coat from running." Most importantly this eliminates sanding between coats.Next to sanding, I hate runs the most!
I usually put on 4 coats this way, often waking in the middle of the night to apply the last coat!
I'm done epoxying in a weekend, and no epoxy dust! I also believe you get better adhesion, and clearer finish!
I hope this helps on the next hull!!
Jim

[ealger]

Thanks Jim for your addition. I guess I was a little paranoid about following MAS's directions for recoat. I won't get into that here but suffice it say between exceeding the recoat window and mostly because of tiny bubbles in the epoxy surface, I was afraid to recoat without sanding and scraping. (not one of my favorite things to do!)
Surely the bubbles would have shown through subsequent coats, unless I'm in error here.
I didn't have this problem on my prior canoe in 2004 as the MAS epoxy responded differently as it was slower to cure.
Ed...

[Jim Dodd]

Hi Ed
Your right about the bubbles!
I should've inquired about the epoxy brand you were using!
I use System Three's Clear Coat, and have not encountered the pin hole problem!
What caused the bubbles?
Jim

[ealger]

Jim, the actual cause/source of the bubbles is unknown for sure. We stir the epoxy for 2 minutes in which time there are a zillion pin head size bubbles in the mix. In pouring the mix onto the hull, I can see the bubbles on the surface. Brushing gently moves the epoxy and does get rid a a lot of the bubbles but I think brushing introduces some also. The density of the bubbles is perhaps 1 or 2 per square inch. Tipping off only moves them around.
I rolled on the last coat after pouring some mix on the hull. Surface dust was a big problem which forced me to sand!
I've obtained some West System 800 foam roller covers and will clean the hull first as Glen suggests with warm water for the next coat, perhaps on Tuesday next.
Ed..

[Glen Smith]

Ed, I have never tried MAS epoxy but with the few brands I have used I always stir gently to avoid introducing air bubbles. Of course a warm thin epoxy will release the bubbles faster than a thick cold epoxy.

[Glen Smith]

Larebow, I know some builders do use those Swiffer cloths for the final clean up and I haven't heard any negative comments.

[Glen Smith]

Ed, I normally recommend following the manufacturer's instructions but in this case I must disagree with the "aggressive mixing" suggested by MAS. You say that you saw a zillion little bubbles in your mixing cup, well what you see is what you get. Ingredients must be "thoroughly" mixed but not with an aggressive action, this only introduces air into the mixture.