Final dust wipe before epoxy?

Builder's Forum
1

I've got the hull of my MC16.5 just about ready for fiberglass and epoxy but I'm not clear about the final clean-up after sanding the okoume.  It's clear from some note in "tips" that tack cloth is a no-no.  I've vacuumed and wiped with a clean soft cloth, but there's still a little residual dust when I swipe my finger over it.  

How to pick up the last dust?

Thanks!

2

for the epoxy coat it does not have to be dust free.

that said, it should generally be clean.  i just vacume with a shop vac with a brush fitting that has broom-like bristles in a circle.  the bristles kick up anything large enough to be of concern so the vacume picks it up.   

fwiw, i would avoid cloths at this step.  in my view, will not make a positive difference and at worse will leave a thread or different color debris on your sanded wood surface.

h

3

After the shop vac like Howard said, I use a lint-free painter's cloth to give it a denatured alcohol wipedown. Once it dries, if there's any dust streaks left, they can be buffed off with paper towels.

Laszlo

4

I gave it a wipedown with denatured alcohol. It took a couple of passes to get all the dust off.

It never occurred to me that one could skip this step. Oh well, next boat ...

5

   Thanks, everyone!

6

   I wipe down with denatured alcohol for two reasons. 

1. Cause I always do it. 

2. Cause it will clean and dry and show me what the resultant wood finish will be.  Sometimes I don't like it and go back to some sanding. 

3. Cause.......more so during fill coats.  My hand prints and oils have been all over it. Don't need any oil contamination. 

 

OK.....three reasons. 

7

I agree. Vacuuming removes enough of the dust for the epoxy coat to go on fine - we add wood flour to fillets/filler after all - but oily thumb prints are another matter. I'm sure the few times I've had problems getting an even epoxy coat have been because of a contaminated (oily) surface when I've forgotten to clean with denatured alcohol on a paper towel.

8

Yeah, we used a lot of denatured alcohol on the boat during our PMD build.  The "natured" alcohol (i.e. Maker's Mark), on the other hand, we saved for after the build sessions to avoid confusion.  <;-)

.....Michael