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Soda Blasting

Posted: Sun Feb 13, 2011 11:22 pm
by LandVF36
Anyone have it done before?
When we pulled the boat in the fall, I spent two days crawling in the gravel with the pressure washer taking off layers and layers of paint. I got down to to what looks like an expoy layer, over some bottom paint. In places, about 30%, it sluffed off, all the way down to the orginal glass, but its realy patchy. I've been looking over the winter and assumed that it would be expensive to have it soda blasted. I was about to make a bulk purchase of 80 grit paper, new charcoal packs for the respirator, and some chem suits, when I found a guy that does soda blasting. Its only going to cost me $300 to have it all taken down to the glass!
So, just looking for input. I plan to look for blisters, fill if I find any, then do 2 coats of Interlux 2000 epoxy, and then 3 coats of Micron Extra (right stuff for the mississipi alge growth)
Mitch

Posted: Mon Feb 14, 2011 12:08 am
by ready123
Gelplane is better than soda blasting which will force particulate into the glass matting that you need to get down to for full blister removal.
http://www.hotvac.com/gelplane/default.aspx

If you do find blisters my understanding is that proper drying is the key to prevent do overs... heated vacuum drying to be specific.
http://www.hotvac.com/
Do it yourself?
http://www.boatdesign.net/forums/fiberg ... 28611.html

Posted: Mon Feb 14, 2011 6:39 am
by prowlersfish
Do not remove the gel coat !!!!! Thats what Gelplane is for . thats asking fo blisters .

If your going to soda blast I would think about coating it with the Interlux 2000 epoxy. Trojan hulls do not have blister issues , you may find some but it won't many . The best time to look for blisters is when it is first hauled out , be for the hull is dry .



Again stay away from that Gelplane unless your hull looks like it has chicken pox with blisters ( it wont )

Posted: Mon Feb 14, 2011 12:34 pm
by captainmaniac
If the price for the blasting sounds cheap, then make sure you check out some of the guy's work... Someone who has the equipment and normally blasts cement or brick might be a little too agressive for fibreglass. Make sure he doesn't just know how to blast, but actually knows how to blast a boat.

Interprotect is generally a good insurance policy if you have it stripped down that far anyways. Having said that, paraphrasing a comment I got from my marina manager a couple of years back "If the boat doesn't have any blisters after (in your case....) 37 years, it ain't gonna get them".

With the Micron - if you haven't already thought of this or were not aware of the technique : you should apply the first cost in an offending colour (like maybe sea ray green), then the remaining coats in the bottom colour you want. When the offending colour starts to show through, those spots need touchup and recoat. Keeps you from piling too much thickness on over time where it's not needed, and makes sure you hit the spots that do need it.

Posted: Mon Feb 14, 2011 8:18 pm
by alexander38
Searay green. That's funny :lol:

Posted: Mon Feb 14, 2011 9:00 pm
by Audrey II
The Quote to soda blast my boat was about $2500. I choose to have in sanded and then I painted with Petite three coats of barrier then one coat blue epoxy and two coats black ablative.

If you paint it yourself be aware timing is key to long between coats and it wont hold. Be sure to check the weather reports before you start to be sure you can finish within the time constraints.

$300 sounds to good to be true get references or buyer beware.

Posted: Wed Feb 16, 2011 7:07 am
by foofer b
i HAVE HEARD THAT SAnd blasting with walnut shells is the way to go. It will not eat away at the gelcoat.

Posted: Wed Feb 16, 2011 7:35 am
by Audrey II
Most people in my area soda blast. There were just three boats done in my yard. These boats look great stripped down to the gel coat without damage in they still require a light sanding before paint can be applied.
If I had the money I would have had it done as well. Sanding as I did came out great but was a big job.

Posted: Wed Feb 16, 2011 9:50 am
by jimbo36
foofer, What if you are allegic to nuts?? :lol:

Posted: Wed Feb 16, 2011 7:24 pm
by foofer b
Then have your wife do it.

Posted: Wed Feb 16, 2011 8:23 pm
by Wes
When I wanted to completely clean our boat bottom I considered soda but the head painter recommended sand. He told me that soda was fine for just cleaning it up but if you want to do it properly sand was better. After it was blasted I put 4 barrier coats,1 tracer coat and 2 coats of ablative on her. That was 3 years ago and she's still looking great.

Posted: Wed Feb 16, 2011 8:54 pm
by captainmaniac
When I did my bottom a couple of years back I tried a commercial stripper called Peel Away first - that attempt failed miserably (may not have been the product's fault; getting rained on in my winter storage shed buggered things a bit... but that's another story). Anyhow... I ended up doing it all by hand - scraping and hand sanding (roughly 3"x8" block with 80 grit) the whole friggin bottom.

If you want quality time with your baby's bottom, and your arms to fall off, go for it. If you don't want to be blowing blue snot for the next 2 weeks (or whatever colour your current antifouling is) ... don't.

Total time invested to attempt stripper, clean up the mess, then manually remove, prime, and 3 or 4 coats of antifouling - about 100 hours.

Posted: Wed Feb 16, 2011 9:17 pm
by alexander38
Got to ask why didn't you use a DA sander ?

Posted: Wed Feb 16, 2011 9:51 pm
by captainmaniac
Two reasons : first, I didn't trust myself to not go too far when adding power to the equation and going through the gel... and second, dust clouds... I store in a shed - very little air movement, so dust clouds just expand and eventually settle... the stuff doesn't blow away.

A couple years earlier I used a sander on a small patch near the bow. Ended up finding some blue sanding dust on my foredeck and could even find some as far back as the cockpit - AND the boat was covered at the time! There was also a bit visible on the boats on either side of me.

Following the whole 'do unto others... ' philosophy, I don't like people covering my boat in crap when they do jobs, and I don't do that to others. I knew that it didn't matter what I did to tent the boat; with all the dust that would be created dong the full bottom, I knew there was no way I could really control it, and pretty much a guarantee that a bunch would find a way out of the tent and land on top of someone else's boat. So... doing the job by hand helped keep everything under control.

Posted: Thu Feb 17, 2011 12:00 am
by LandVF36
Thanks all. I did ask for references. He's sending them with pictures. I've not seen any blisters when its wet. There are a few patches in the hull that were not primed right and the bottom paint sluffs off every years, but clear and smooth as could be. The sea-ray green for the first layer of bottom paint is a smart idea too, I'll do that. I know we all like pictures, so when I get going, I'll post some.