Blasting of bottom paint

[Rob Hessenius]

Congradulations

Mike-
Congradualtions on the completion of your project. So you found a few muscles that were moth balled. You will enjoy the fruits of your efforts.

 

[rod sanburn]

Soda Blasting

I puchased a soda blast unit from Eastwood they are a car restoration supply house. It works very well. It takes they bottom paint down to the barrier coat but does not harm the barrier. Eastwood has a 250.00 US unit and also has a retro kit if you have a media blaster already. They also sell the soda media in 50 lbs bags, 2 types. 39.95 a bag. I have not finished yet waiting for the weather to break. www.eastwood.com Rod

 

[jkenan]

Peel it...

I had my hull peeled, not only to remove all the bottom paint, but also to remove the gel coat due to blisters. The PO had done a barrier job, but applied the barrier paint to a blistered hull without repairing the blisters first, thereby trapping the moisture in the hull and exacerbating the problem instead of fixing it. The yard did an excellent job peeling, and just barely grazed into the 1st layer of mat. Total job cost me $800. I did all the sanding after that (to smooth down the ridges left by the peeler) with 40grit paper, which took all of a day. Now it's just grinding out the areas where blisters prevailed, and washing it down and scrubbing it periodically with a heavy bristle brush, and letting time do it's work to dry it out. There will be some minor fairing to do (yard says it's overkill, but I want a fair hull). I won't go nuts, but think with a little effort here, the results in speed and performance will be appreciated. Peel job was in December, and I expect to be applying the barrier in April.

BTW, when I removed some fittings below the waterline, the hull thickness was impressive! I should have taken my calipers and measured, but I would have to guess it was about 1/2". Very well made boats, IMHO!

 

[e38 owner]

Blasting

I wanted the barrier coat off

I was going to try the blasting route but rental company fell through for Soda and Marina would be opposed to Walnuts.

Has anyone tried a Sander similar to the Hutchins recommend by Guy.
Scraping has not worked well.
Sanding is Slow
Thanks

Any thoughts on how to proceed.
Hull has some minor blisters. need repairing
Barrier Coat is solid in most places but has thin spots so more coats are now needed.

The Barrier coat was applied over some bottom paint and epoxy in some areas. Those remaining are solid??

 

[SASSY]

Bottom Job

I just had the Hull peeled on my 87 E-34. We also went down to the glass and fixed up some blisters. Cost was $900.00 plus fairing. I replaced the gel coat with 2 coats of industrial high build epoxy primer and four coats of barrier coat. 1 word of prep advice would be to wipe the entire hull with a solvent such as acetone to remove any residual moisture prior to the first aplication. I did the same job on my dads Cal 3-30 last year but did all the fairing myslef, never agian. Now it's bulit proof, and gives me peace of mind. Looks good.
On the other hand I do know people that have had the boat blasted with walnut shells and were very happy with the results. One word of caution with wich ever approach you take is you don't know what you getting into until the old paint is off and chances are there will be a little more work than you expect. I found it is the only time I wish the boat was 5 feet long instead of 35.

 

[P Abele]

Has anybody tried using dry ice blaster for removing bottom paint? I have heard it mentioned as an alternative to walnut shells but don't' know if it is more or less harsh - although I am sure there are a bunch of variables.

 

[Salty Dawg]

Soda Blasting

I recently had my E32 soda blasted to remove 15 years worth of bottom paint. I contacted several mobile blasting companies in my area and was able to negotiate the price down to $400 plus mobilization of $50. It took them 3.5 hours to complete the job without a single break in the gelcoat. The bottom was so smooth I had to chemically etch before application of the Barrier Coat. I have vowed to never sand another bottom as long as I live. Ablative bottom paint and soda blasting is the only way to go. Total time to complete bottom was 2 relaxed, enjoyable weekends.

 

[ted_reshetiloff]

Salty has it spot on here. I stripped my bottom a few years ago the hard way. Never again. Now I lightly sand with 150 grit on the vacuum attached DA and apply new paint. I use Petit Vivid in white which is $200/gallon but really works well on the chesapeake. I have a diver hit the bottom once a month from June-Sept. Combine that with power wash on haul out and there is just enough left that 150 grit does the trick.