Bottom Paint Removal

[BubbaThePirate]

That makes more sense. I never should have doubted you. :o)

Todd

[Bob Condon]

I did this work several years ago and like John Stone, I tried chemical strippers and got marginal results...

I took a belt sander and a shop vac, got a 1" vac hose.

I did not try soy stripper, but use the woosy orange stripper, tried 5f5 and then gave up after it ate my gloves

I had 14 coats of paint on my intrepid 28.

I put down a BIG blue tarp and dampened it down so that anything that did float off the belt sander (3x21 old craftsman). Tyvek suit and respirator...

The job took a solid afternoon. I was lucky because the last coat before the gel coat was red. Everything else was blue so I could use 28 grit paper and go to town and once red started to show, move on. Then went to 80 grit and 150 grit

The vac sucked up most but it was a mildly windy day so some came off the belt sander and hit the suit + Tarp and stuck... A person looking for donations came by and I was blue from head to toe... The fellows comment was that he did not know that smurfs worked on boats.... I gave him a donation later on because he made me smile for several hours!

I used chemical removed at the end and the bottom came out smooth. I cleaned up the vac + pitched the sander and tarps, suit etc.

The paint dust was very heavy! so I was glad I cleaned it up. I only use ablating bottom paint which comes off with the protection and put one coat on each spring and second coat on the leading keel and bow edges.

Ended up being pretty cheap ($100) to remove and my labor...

Bob

[gates_cliff]

I got a quote to have the bottom paint removed by some kind of mechanical stripper. I gather it's like a planer, they recommended this method over soda blasting, which is what I inquited about first. I had heard about a machine that takes off the entire gel coat but never heard about this method for removing bottom paint.

Does anyone have any first hand knowledge?

In addition, I have a couple of quesitons about barrier coat and new bottom paint.

Do you have to apply the barrier coat right after removing the old paint?

How do you know how many coats of barrier coat you need?

Is it usualy best to wait to put on the antifouling paint right before putting the boat back in the water?

Thanks

[Johnd]

What's the best time to put on a coat of ablating paint before putin? I am guessing a couple of weeks at best?

Thanks,

John d

[Jim Evans]

Hi Cliff,

A couple of years ago, while on the hard at Shipwright Harbor in Deale, MD, I had my CD33 bottom paint mechanically stripped. They did a terrific job, and I'd highly recommend them for the work. Once they finished, I went back and sanded the bottom with a random orbit sander to clean it up, wiped the bottom down with acetone, and applied ablative bottom paint (Ultima SR60). I have no regrets.

I'd think carefully about a barrier coat. Given the age of our boats, and the general lack of blistering problems with Cape Dorys, I'm not sure it's worth the expense. I considered it, had my marine surveyor come out to give me a recommendation after the bottom was stripped, and came to the conclusion that it was not worth the trouble. IMHO.

[Johnd]

My 22 has a fairly smooth bottom, with a coat of Micron CSC from last Spring. It needs another coat after two power washes. With an old green slime rim around the boot, how should I go about sanding it out? I will do it by hand, just need to now which grit to use on the scum and rough areas. Should I clean it with acetone before applying new coat?

Jd

[jbenagh]

I have wet-sanded with 400 grit on a soft sanding block. For soft sanding blocks, I use the sponge sanding blocks in whatever grit I have and then put the 400 paper around it. You will need to polish afterwards to remove the small scratches. I would not use this method on paint.

Jeff

[Johnd]

I have wet-sanded with 400 grit on a soft sanding block. For soft sanding blocks, I use the sponge sanding blocks in whatever grit I have and then put the 400 paper around it. You will need to polish afterwards to remove the small scratches. I would not use this method on paint.

Jeff

Thanks Jeff. My dried algae stripe actually is on the bottom paint, which was raised up to meet the boot stripe. I was going to just run a hand held dry sponge sander and scrub it off, then clean and paint.

[jbenagh]

on bottom paint, you can be super-aggressive. In Salem, we apply bottom paint every year, so any damage to the bottom paint is sort of irrelevant. I use 80-120 grit on an orbital sander to prep the bottom paint. This takes off algae and anything else.

Jeff

[Johnd]

OK, good to know. I appreciate your help.

Johnd

[captzigzag]

Hauled my 33' boat last month. It was $400 to pressure wash, sand, small fills and paint. I ordered 2 gallons of Micron Extra Red for $412 delivered from Wholesale Marine. Had the job done at Port Salerno Marine, FL. I could have done it, but for $400 why not spread around the wampum?

[Johnd]

In the DC area, you may be looking at Wampum x 2, which is real Wampum...

[valenteach]

I looked in the archives of this board before doing my boat's bottom, and there were mixed responses. Over time there are changes in the options and products too. Nothing in the older posts really gave me a clear idea so I had to experiment before choosing the method. After going through the process of removing all bottom paint on my boat I's say the two pieces of information that were not stressed enough in previous posts were (1) the condition of the bottom paint you want to strip/remove and (2) the forewarning that if the old paint is solidly adhered and really can't be done without using stripper, not all types of old bottom paint react the same way towards Soy Strip or other products.

My hull had many years of old bottom paint that were brittle, flaking, loose, and very dry. Some places you could just flick it of in huge chunks with your finger to reveal gel-coat. In hindsight I realize it's the easiest type of bottom paint to deal with. When I experimented with Soy Strip, it just turned that nice dry flaky stuff into a pasty mess that smeared and left a sticky colored residue instead of clean-dry gelcoat. It also did not soften all layers of paint unless I did multiple applications or left it on longer, which then would start to soften the gel-coat, so I was caught in a catch 22. I also found I had an additional step or two of removing smears before the gelcoat was really bare. So I instead went with a wide, sharp, large-handled painter's scraper with replaceable blades, which took everything off cleanly, slid across the gel-coat and left it alone, and left a nice gel-coat surface that just needed a very light sanding and washing before I applied a barrier coat with Interprotect 2000 two part epoxy system. In my opinion, if you are going to do the work of getting to the gel-coat on a boat bottom, it makes good sense to protect that gel-coat with something more than just ablative paint.

I didn't need a hazard suit or 100 sanding disks and I didn't make a cloud of toxic dust that floated onto my neighbors tomato plants. Put I did cover up and use a respirator. I have to say if your bottom paint is dry and flaky, the scraper is hard on your biceps but easy on the environment. There is not a huge pile of toxic plastic and pasty bottom paint to dispose of, just a paint bucket or two of dry paint chips that you can leave in your garage for whoever inherits your property.

It took me a week of long days to scrape, sand, clean, prep, fill dings and fair, and then apply the epoxy. I also removed thru-hulls for my work, but I don't think the 10 hour estimate from the 36' owner is realistic for a full removal of ten or twenty years of old paint down to original gel-coat using any method, even if you don't remove thru-hulls or do other glass/fairing work.

When I get my next boat (CD 33 hopefully), I will probably do the same thing, but if the paint is not dry and brittle and does not respond well to a scraper, I would go with Soy Strip (put it on thick and use a good plastic covering).

[dawnhoward]

We started sanding.... went to scraping...and are now sanding. It has taken 16 man hours to scrape the port side & sand half of it. Wow what a job. It will be done right this time so we won't have to do so much prep work to paint the bottom the next time it needs to be done.
We are talking about re-gel coating it. She will be beautiful once she is done.

Cheers!!

[sealark]

Some updating on "soda blasting".

My plan has always been to have the bottom of my 25 "soda blasted". As I am getting closer to having this done - I called the guy doing this last week and had a discussion.

I am no expert - but this is what he told me.

Just like sand - soda is simply the media used for removing the paint.

Sand is very course - and not typically used for removing paint on boats - as it is pretty aggressive and will probably remove some gelcoat.

Soda is very fine - but is not necessary to use in order to prevent damage to the gelcoat. Soda has odor removing properties and is typically used on stuff like wood furniture after a fire in a home.

He will be using a different media - sounds like some combo of crushed glass.

My guess is the vast range in pricing is based on the media that is being quoted.

I have a trailer so I will be bringing the boat to him - so based on that - my price is going to be about $600. And he will have it done in about an hour. For me - it is a no brainer. He told me that if I insisted on using "soda" - it could be as much as double.

And for the larger boats - he does offer mobile services - so I would imagine most guys that do this would.