Soda or Glass Blast

[eherlihy]

I recently contacted a reputable firm to soda blast the bottom of my hull. The guy came by and gave me an estimate, but said that he does not soda blast any more. He now uses "recycled glass."

Soda blasting, he says, requires that the hull be sanded with 60 grit in order to give some tooth for the paint. This is not required for glass blasting. He also said that if he used soda that the hull would need to be "neutralized" to get the PH right before painting. I understand that soda is mildly caustic, but would a hull that was soda blasted require neutralization before painting?

His estimate came in at exactly the price that I expected for soda blasting. I realize that "recycled glass" is really silica, aka SAND... My suspicion is that it is cheaper (for him, not necessarily me).

Which is preferable??

Thoughts?

[eherlihy]

One more tidbit:

If it were not for the guy's reputation, I would have discounted the use of anything but soda to blast strip the hull. This guy used to do soda blasting, but he says that he switched to "recycled glass" because, in his opinion, it is better.

[RXBOT]

I have heard that walnut shells work well and can be reused 2 or 3 x before the edges get too dull to be effective. Also read that sanding was not needed after blasting with shells. Will be interested to hear from anyone with direct experience with different mediums for blasting.

[bljones]

If he's glass blasting, i hope he is completely tenting the hull, tarping the ground under the boat and cleaning up everything after. Ground glass is hell on your lungs, and it doesn't take a lot of ingestion to ruin your whole day.

Silicosis - PubMed Health

[tommays]

A friend down the street had his boat done with something other then soda and it was to agressive and required a good amount of extra work beyong a qiuck trip with a 60 grit DA

I own a cabinet blaster and a good collection of media and you have to be carefull even on metal

[celenoglu]

Search also for dry ice blast. Dry ice is frozen CO2, after blasting the material evoporates as gas and nothing remains nor on the boat neither in the surrounding.

[BarryL]

Hello,

I know nothing about glass bead.

Soda blasting does require light sanding to give the hull some tooth. It's not difficult, and would certainly remove any caustic material. Then again, before you paint you want to wipe the hull down with something anyway.

My boat was soda blasted a few years ago (i've posted the story a number of times, let me know if you want the link). The hull came out very nice and it was easy to prep it for paint. Another guy in the same yard had his boat sand blasted and the hull was a mess - lots and lots of gouges, pits, holes, etc. He spent a lot of time filling and sanding.

good luck,
Barry

[eherlihy]

Thank you for all the replies.

My concern that the glass would be too aggressive seems to be shared.

Unless I read something in support of "recycled glass" blasting, I will push this project off for another year, and another contractor.

Barry - I have seen your post, and it was very helpful. I also own an O'day 35 (deep keel).