Grit blast

[DavidGrieves]

Hi

I need to grit blast after a gel coat peel, not many companies local who have experience of blasting a GRP hull. I need advice... What grade grit do I need? What pressures should be used? What type and size of nozzle should be used?

Many Thanks

David

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[bruce]

be careful, would look into the new 'Ice grit' system ya'll have over there, supposed to not damage gelcoat. what ever you do, would have expert do it that knows gelcoat.

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[simonwood]

I believe it uses dry ice and got a very good review in PBO or someover yachtie mag. well worth a look.

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[oldsaltoz]

G'day David,

I would have second thoughts about grit blasting after all the gelcoat has been peeled off, you stand a good chance of contaminating the raw glass.

Sanding with an 80 or 60 grit is fast, even a small concrete grinding wheel will make short work of the area.

And, even if you find a suitable grit (recycled glass is one) and the correct pressure and nozzle, the job will only be as good as the bloke holding it.

You are going to have to fair the hull regardless of the method used, and a sander will provide a good base to work from; just make sure you remove the undercuts left by the edges of the peeling tool, look for glossy lines.

Little tip.
Before you do anything, wash the area with fresh water and look for any areas that the forms beads on, indicating contamination or silicon, chemically remove this first or you will spread it further and have a larger area to treat.

I hope this helps and good luck, keep us posted on your progress.

Andavagoodweekend........



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[Bejasus]

have a look <A target="_blank" HREF=http://www.farrowsystem.com>here</A>.

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[Althorne]

Was owner of a grit blast business for many years until retirement. Be VERY CAREFULL. Its not as easy as you think. Using grit means you must seperate ALL the water from the air before it picks up the grit otherwise blockages and dirt will make a disaster of the job and contaminate your hull rendering it unsalvageable.
Pressure will almost instantly disolve fibourous material leaving holes and allow contamination to the interior. Bad weather partway thru job could make it all a waste of time and money unless under cover. Health and safety will nail you to the floor if you don't protect everyone in the near vacinity. Clearing up can be just as hazardous...........shall I go on. Now you know where a lot of your money goes. It's always greener on the pther blokes side........
My suggestion....try a quote or too from a well insured expert.

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