Antifouling paint stripper

Zonker

Super Anarchist
9,663
5,621
Canada
Our sailing co-op is considering using paint stripper to remove many years accumulation of hard bottom paint. 

Anybody done this and how happy were you with the results? This is a Catalina 27 with probably 6 - 10 layers residue.

Local costs for Dumond Safety Strip would be about $600 (a gallon only covers ~20 ft^2)

 

IStream

Super Anarchist
10,860
3,040
If you've got cheap labor available, scrape to extend coverage and then chem?

 

Zonker

Super Anarchist
9,663
5,621
Canada
The bottom is really really rough on some of the boats. Very patchy and flaking off in big chunks because it's so thick.

Every year we sand residue of the previous layer of hard paint but the cheap labour (co-op members) is lazy and doesn't always do a good job

 
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I've done 2 buddies boats this way. It's messy but works well. Use tarps under the boat and full tyvek suit/hood/goggles to protect yourself

The secret is to work in the early morning moisture so the stripper doesn't dry out on you otherwise it loses effectiveness and you end up using much more.

A hot day is the wrong day. 6-7 layers is a lot and may require a few runs of stripping but it will get the job done. You'll still need to sand some areas where the stripper didn't get to but easier than sanding the entire boat.

 

IStream

Super Anarchist
10,860
3,040
The bottom is really really rough on some of the boats. Very patchy and flaking off in big chunks because it's so thick.

Every year we sand residue of the previous layer of hard paint but the cheap labour (co-op members) is lazy and doesn't always do a good job
So much for that idea. If they're too lazy to sand, they're too lazy to scrape.

 

Zonker

Super Anarchist
9,663
5,621
Canada
We scrape first then sand. But it's never 100% and people get tired of doing it and finally we say good enough and put on a coat of paint.

 

Foreverslow

Super Anarchist
Did mine this past winter.

Use a pull scraper and keep the carbide blades sharp to get the really ugly stuff off.

Tarp on ground to catch the debris.

Should take maybe an hour.

Then roll on a stripper from a pan and a 3/8" roller cover.  I just took 7 years of Pettit sr60+ off with Citrus Strip from Home Depot/Lowes. Shitload cheaper than anything with an anchor on the container, and no fumes.

The trick is to press a layer of plastic sheet on it while wet.  Thin film is fine, but I like the slight thicker stuff so the wind does not fuck with it and use the 4 foot  wide stuff so I can peel back a manageable area . 

https://www.homedepot.com/p/HUSKY-3-ft-x-100-ft-Clear-4-mil-Plastic-Sheeting-CF0403C/202184120

Tape top against the hull well with masking tape so it does not fall off.

Let it set overnight.  In the morning peel only about 2-3 feet at time and using a pull scraper pull down.  I keep a 2 gallon pail to flick the dissolved paint into so the tarp below does not become a slimy mess.

Then a light sanding with 80 grit  on an orbital with the hose to a dust deputy and ultimately a shop vac.  The dust deputy will grab 80 percent of the residue.  If rolling without a barrier coat rebuild, one last pass with 150-180 followed by a hosing/wipe down and you will be set for another decade.  Next time it will not be your problem.

 
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sailhmb

Member
290
50
half moon bay
We did 6 cal 20s to switch over to copper coat.  Dry out was problem.  Foreverslow has a good technique.  Put on your hazmat kit and go to work.

 

Marcjsmith

Super Anarchist
3,881
1,044
Washington DC
zonk,

I used some whale snot stuff on my moody when i was working on the hull last year.  30 years of AF.  it was working.    it was peeling the old Ablative off.  but it was taking a while.. when I get home tonight  I'll take a pic of the 5gallon bucket were were using.

in some areas  the pain peeled right up.  in other spots not so much.  but I think that might have been applicator error...

the down side, is that   it felt like you were working with, whale snot.  it was slipper gooey, got everywhere, and kind of a nuisance.  forever slow has the technique.  Id also add the very wide flexible putty knives with the ouder edges rounded to minimize gouging   to the tool arsenal.

if you were closer and stateside,  I'd send you what i've got leftover...

 

sailorman44

Member
281
71
CT/FL
I used Peel Away on two different boats and it has worked very well. It is very thick and is applied with a trowel 1/8 to 1/4 thick, then covered with the provided paper to slow evaporation. Let set for a long time, test to determine the time required, it could be 24 hours or more. Peel down with a putty knife and the paint sticks to the paper so clean up is easy. Takes off multiple layers of paint. Be sure to neutralize. There are two varieties, be sure to get the right one for your bottom paint. It is relatively expensive, Defender had the best price and it takes a lot to get the job done.

 

Marcjsmith

Super Anarchist
3,881
1,044
Washington DC
Zonk.  I used blue bear 670

I've got a about two gallons left over.   yours if you want it.  not sure how cost effective shipping would be though...

my zip is 22182 Vienna VA  if you want to investigate...

 
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GMiller

Anarchist
606
51
Eastern NC
I have made my own for cheap using lye powder, corn starch and warm water.  Worked a treat if you can keep it from drying out.  As with most things, the prep work was the hard part and the actual removal of product was easy.  I then pressure washed to neutralize and sanded.

 
Listening to the hassle here and thinking about the net cost for a couple gallons of the stripper... has me wondering if it's not time to call the soda blaster, drop the money and spend the bottom stripping day in a local sports bar drinking beer and watching the  baseball / football / hockey of your choice.  With Tyvek suits, scrapers, trash bags and everything else, it has to be getting close to the cost of a soda blast.  

I have a 35' boat and do the racing bottom each year, sometimes coarse sanding down to the Interprotect before spot re-fairing, and the amount of work you guys are suggesting makes my back hurt more than that just to think about it. 

 

charisma94

Fucking Legend
1,342
327
Palma de Mallorca
We've tried several stripper methods & products in our yard over the years. But the effort, mess, PPE and pretty substandard job in the end made us go back to Soda Blasting. Cheaper in the long run, safer, easier and better job for sure. YMMV

 

slug zitski

Super Anarchist
6,150
1,197
worldwide
We've tried several stripper methods & products in our yard over the years. But the effort, mess, PPE and pretty substandard job in the end made us go back to Soda Blasting. Cheaper in the long run, safer, easier and better job for sure. YMMV
Yes

the paint strippers are a mess

on a small boat , in which you may need to crawl under the hull , it’s a nightmare 

i would prefer to dry scrape with a sharp push scraper 

blasting is the best solution .. many folks have this equipment 

a blasted bottom is not expensive 

 

Foreverslow

Super Anarchist
I used Peel Away on two different boats and it has worked very well. It is very thick and is applied with a trowel 1/8 to 1/4 thick, then covered with the provided paper to slow evaporation. Let set for a long time, test to determine the time required, it could be 24 hours or more. Peel down with a putty knife and the paint sticks to the paper so clean up is easy. Takes off multiple layers of paint. Be sure to neutralize. There are two varieties, be sure to get the right one for your bottom paint. It is relatively expensive, Defender had the best price and it takes a lot to get the job done.
the peel away you get from Home Depot is chemically the same as the stuff you get from your chandelry.

Only the paper does not have the little anchors on it. I checked the MSDs and the called the folks in Long Island.

Same stuff,  just a premium for the anchors on the paper if you are so inclined.

and the stuff does not work below 40 degrees.  The folks there laughed at me when I asked why it was not working in the middle of winter in New England.

I find Citrus Strip works better and is MUCH easier to apply provided you use a 3/8" roller and not a paint brush.  Then lay on a sheet of plastic.

 

nota

Anarchist
hot air ? they make heat guns for that

back in the stone age I used a blowtorch on a wood chriscraft  bottom

it worked the paint would soften then bubble hit it then or it will bake and not come off

but at the right temp it came off in big sheets fairly eazy

 
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Boatzilla

Member
299
12
PNW
Just did a Sydney 38 with 15 gallons of peel away. It worked great in PNW October weather. I would certainly recommend it for significant buildup. 

 

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