Experience with soda blasting anyone?

[Ed Schenck]

Tomorrow morning I have contracted to have my keel cleaned to bare lead. Years of modified-epoxy paint buildup are beginning to peel off in places. I hesitate to tell you how much they charge an hour. Has anyone seen soda blasting done? How long will it take to do my keel(pictured).

Another reason for asking is that I wonder how long it would take to do the entire bottom down to the barrier-coat. A few years ago I switched to an ablative. Now I think it might be nice to start over. Or should I worry that soda blasting will damage the barrier-coat?

P.S. I did call and was told they won't know until they see it. And I cannot be there.

 

[sailaway78]

Soda Blasting

I have done one boat with a soda blaster, and wouldn't consider anything else. Fast, fast, fast. Nothing to damage the environment. First time it rains, it's gone. You do have to be a little careful, depending how big the machine is, cause you can take the gel coat off pretty quick with a really big high power one.

 

[Ed Schenck]

But "what does "fast, fast, fast" mean? How long to do that keel? Or maybe "it depends", like how many coats and how hard.

 

[woodster]

I have done one boat with a soda blaster, and wouldn't consider anything else. Fast, fast, fast. Nothing to damage the environment. First time it rains, it's gone. You do have to be a little careful, depending how big the machine is, cause you can take the gel coat off pretty quick with a really big high power one.

i hope its ok to take the gel coat off as i am sanding mine off and am about 70% done.....

regards

woody

 

[Ed Schenck]

Why are we talking about gelcoat Woody? I have a lead keel and a barrier-coated hull below the bootstripe. Do I have to worry that it will go through the barrier-coat and damage the gelcoat?

 

[woodster]

Why are we talking about gelcoat Woody?

to answer your question Ed.....i was responding to a comment in an earler post on this thread.......but just maybe i should have posed my post as a different thread...wasnt trying to hijack your thread....

regards

woody

 

[Bryce22345]

Ed,
I had my 98 H410 soda blasted from the water line down a couple of years ago. they charged me by the foot at the water line. you didn't say what they're charging by the hour, but its probably cheaper than I paid by the foot. I didn't have a barrier coat (some other product was used) but it took everything off to the gel coat. didn't touch the gel coat. they did three other boats in the yard the same day they did mine so what, 3-4 hours max. sure is a nice smooth bottom now tho.

 

[sailaway78]

Couple hours tops

Wouldn't take more than a couple of hours tops, to do a keel. Probably an hour if the operator knows what he is doing. As to taking off the gelcoat, you can do this with any blasting media, be it glass beads, walnut shells, sand or soda. But the soda leaves a really nice smooth finish, more so than some other media. And like I said, clean up just takes some rain.

 

[Ed Schenck]

Called that pretty close Phil. Looks like four hours for the entire bottom at $150. per hour. He called and quoted $600. He found the keel was coming clean with some difficulty. Can't wait until Thursday when I can go and see the result. I hate having anyone work on my boat, especially when I am not there. But this year it is the only way. Next is to get quote for wash and wax.

 

[sailaway78]

Not too bad

That doesn't sound too bad. When I did the only one I have done, I rented a machine, and as I recall it was around 400 bucks for the machine and soda. Took longer to go get the machine and return it than to do the bottom.

 

[sailingdog]

I used a sodablasting vendor back in 2007. The price was quite reasonable and the amount of effort it saved me was well worth it, especially given I have THREE hulls, not one. A lot depends on the skill and experience of the sodablasting operator—a good operator will get the boat down to the barrier coat or gelcoat as requested quickly.

One issue is that you do have to coat the lead with something relatively shortly after sodablasting it. Lead will oxidize and that can cause issues, but it isn't anywhere as bad as a cast iron keel from what I've seen.

 

[sailingdog]

Why are you removing the gelcoat. Unless your hull laminate is saturated and you're trying to dry out the laminate, there really isn't a good reason to blast the gelcoat off. While you can barrier coat raw fiberglass, it would make far more sense to leave the gelcoat intact and barrier coat over it. Then you will have two layers of defense against osmosis—the osmotically resistant gelcoat, which in many cases was a vinylester, rather than a polyester, resin, and the barrier coating itself.

i hope its ok to take the gel coat off as i am sanding mine off and am about 70% done.....

regards

woody

 

[woodster]

Why are you removing the gelcoat. Unless your hull laminate is saturated and you're trying to dry out the laminate, there really isn't a good reason to blast the gelcoat off. While you can barrier coat raw fiberglass, it would make far more sense to leave the gelcoat intact and barrier coat over it. Then you will have two layers of defense against osmosis—the osmotically resistant gelcoat, which in many cases was a vinylester, rather than a polyester, resin, and the barrier coating itself.

there is a lot of dry voids about the size of a half a dollar in the surface mat and i also had a lot of gouges and some blisters as well so while i am doing this job i decided to go this direction ....i will be using west system epoxie and additive to the tune of about 10 coats...i am sanding with a random orbital sander(dynabraid) ..it brings up the fibers in the material and if i am correct will give me a better bond in the over all apllication.....also i didnt trust the gelcoat as it was 31 years old and seem to be a little chalkey and along with the wax that was on the surface ...hopefully all this hard work will be to the betterment of the out come.....


regards

woody

 

[Ed Schenck]

Well today I got to see the results of soda blasting the bottom and keel. I was pleasantly surprised. Might have been worth that big check I wrote. You can see that a little black(original antifouling) remains on the barrier-coat. But better than going through to the gelcoat I think. The keel is much smoother than I thought it would be, just four or five scarred sections to fair. I think I can recommend the process.

I used to paint the entire bootstripe and put one coat on the bottom in a day. With my new schedule I was able to do the stripe on one side. Not sure how many more years I can bend over looking through my bifocals to put on 74 feet of tape.