Fiberglass dust. Do I need to clean up every speck of it???

[Darren Nemeth]

The Batboat is completely gutted out. Already have the transom in and the stringers and deck will follow after I biaxial in the spots where I ground some of the old glass down to the gel coat.

I did a great deal of grinder work in the hull and blew the vast majority of the glass dust out with a 10 gallon air compressor.

All deposits and clumps are gone.

It is almost all gone except for a very light dust the air blasts couldn't get out. I can wipe it off with rags and acetone but do I need to get it all out of the boat?

Will just a little bit of it harm my efforts in wetting new glass down on the hull or will the ploy resin assimilate it since it is just fiberglass dust?

The top side needs to be wiped completely clean but how about the area that will be under the deck?

 

[danond]

Re: Fiberglass dust. Do I need to clean up every speck of it???

You're fine. A tiny bit of fiberglass dust won't hurt a thing. Remember - people mix wood flour, talc and other sorts of crap into epoxy and polyester resin to thicken it. You're not doing anything different by having a few specks of whatnot in there.

As long as it's not greasy/grimy/wet, you're good to go.

 

[erikgreen]

Re: Fiberglass dust. Do I need to clean up every speck of it???

The big thing is making sure there's not enough of it to form a layer in between the new resin and the old. If that happens you're essentially putting wax paper in between your repair work and the original, which means you get to re-do the repair. Surprisingly little dust will weaken even an epoxy repair.

Put it this way... if you have so little dust left that it's not a problem, then you may as well finish cleaning it up anyway. Vacuum up as much as you can, then run a damp rag over the whole thing and let it dry, and you should be ok for degreasing with acetone or xylene, then glassing.

Erik

 

[rucaradio]

Re: Fiberglass dust. Do I need to clean up every speck of it???

I might get poo-poo'd for this, but when I was done grinding I used a shop-vac, a air chuck, even my gas powered blower to try and get all the dust out. I got all the big chunks out, then used a garden hose and sprayed EVERYTHING down.

Put the nose of your trailer up so the water will drain out the bilge, and leave it in the sun for a few days. Everything drys out nice and there's no dust left.

 

[erikgreen]

Re: Fiberglass dust. Do I need to clean up every speck of it???

That's a good plan if you can easily tilt the boat and drain the water.

Painting or fiberglassing, the dust from sanding sucks, but there's no easier way to compromise your work than by leaving some dust in the boat and not degreasing the surface... even a newly ground surface can pick up some contaminants... from the grinder

 

[Mark42]

Re: Fiberglass dust. Do I need to clean up every speck of it???

My choice (for this particular job) would be a shop vac and then proceed with the glass work. Sometimes washing just makes a slurry of dust that fills in the rough surface that you want the resin to grab hold of. So unless you can really do a good job washing it clean, use a shop vac. The vac will pull the dust out of the crevices and leave a nice "rough" surface for the resin.

 

[jonesg]

Re: Fiberglass dust. Do I need to clean up every speck of it???

I use a gas powered leaf blower then splash with acetone and start mixing resin. Keeping the project moving along makes it less tedious and more productive.