Paint stripper to remove antifoul?

[pwillems]

Hi All. Spring is fast approaching down here in Oz and I'm about to book a lift to deal with the forest growing under my big 57ft full keeler and put on a fresh paint of antifoul. Budget is limited, so I'll be doing most of the work myself and considering this will be my first go at antifouling, it's a daunting task to say the least. From my reading, using a GRP friendly paint stripper is looking like a nice option, but I can't seem to find information anywhere about the effect it will have on the barrier coat under the antifoul. There are many products that state they will not harm the gelcoat, but I can't seem to find anything about the effect it will have on the barrier coat.

What has been your experience with these products?

[boden36]

I hardly ever sanded our bottom in thirty years, and never used stripper either.
If the existing antifoul is in good condition, I would give it a good waterblast and just recoat.Maybe just sand loose bits. Check with the paint company rep. to confirm.

Regards,
Richard.

[UNCIVILIZED]

Use extreme caution if/when using a paint stripper, particularly if the boat is barrier coated. There are some which are relatively safe, but others will eat epoxy & even do bad things to gelcoat. One such chemical is Methylene Chloride IIRC, & it's found in some paint strippers. And while you should check (& cross check) this for yourself, said chemical is Bad Juju when used on or near epoxy.

[capngeo]

Don't forget to tip the stripper

[valhalla360]

What type of bottom paint do you have?

If it's ablative, don't strip unless there is something wrong. Otherwise, you are just wasting good paint. Ablative works by wearing down slowly over time.

Hard bottom paints on the other hand can do 2-3 coats before, yes, you do need to remove them.

[HankOnthewater]

As Valhalla said in above post.
Just water blast all the cr@p off and any loose antifoul, and if the stuff is really bad you may need a scraper. Note: round the corners of any steel scraper you use, it prevents the scraper digging in!

You mentioned "forest". How long since it has been antifouled? Maybe select a better antifoul. If I remember correctly you sailed the boat from overeast to WA last year? If that coat was put on to sell the boat likely the cheapest stuff they could find.
Do you know what was used before? You may need a separation/barrier coat, but..... 8 times out of 10 you may not.

[rwidman]

Bottom painting a boat is one of the jobs that's best left to people who do that for a living. Not because it requires a lot of education and skill, but because it's a dirty, backbreaking job.

The old paint is highly toxic as is the new paint. You should really wear a full body disposable suit and a respirator, not just a dust mask. This stuff is designed to kill barnacles and works on humans as well.

If you decide to do it anyway, my suggestion is to follow the paint manufacturer's instructions, not something you find on a boating forum. What someone else did may have (or have not) worked for them but your original paint and new paint may not be the same as what they used.

[skiggy]

Hi, I don't know if it any good to you but I am doing the same to my boat as we speak. I bought painstripper called 'STRIPPIT' from CFS (CFS Fibreglass Supplies) and it is marvelous. Takes out all the backbreaking work. You paint it on, leave it for 24hours and then blast it off with water, even better if water is hot and it will work on any type of paint and antifoul, won't damage the Gel coat and can be used on self polishing or leaching antifoul paints. email----sales@cfsnet.co.uk They ship overseas though what the charges are I don't know for you. They sell just about everything you need and as much or as little as you need, send for their catalog, you will see. I live in Yorkshire, this firm is in Cornwall so you will see I have no affiliation with them apart from being a customer.

[sailorboy1]

Originally Posted by pwillems

What has been your experience with these products?

I haven't used any but will be next season as I need to strip the bottom and start over. I've read paint stripper articles and reviews over the past couple of years and yes there are ones that wouldn't strip off the barrier coat. Try a search here on the forum or just a general google search and I bet you get lots of real life hits.

Bet the goods ones will need more than a $2 tip though.

[hellosailor]

"Bottom painting a boat is one of the jobs that's best left to people who do that for a living. ... because it's a dirty, backbreaking job."

Gee, I must have missed something. It felt just like painting a wall in an apartment or home. Roller on a pole, so I could stand back and not have to squat under the hull. (Duckwalking gets old fast, yes.) Hardest part was taping the waterline and not painting past the tape.

Not a fun day, but then again, nowhere near as bad as swamping out the Augean Stables, or other real scut work. Given the cost of bottom paint, this is the kind of job where $10/hour pickup labor can often cost you more than it saves, when they get it wrong.

PW-
Impossible to say if you're doing it right without knowing just what you're intents are. As noted, normally you just clean/scrape the growth off and paint new over the old, unless there's a particular reason (too thick, not adhering, incompatible) that requires getting the old stuff off, confirmed by the paint maker's requirements.

[Djarraluda]

I would start with asking around your mooring area for folks recommendations on what antifoam works best in that area. They all vary between salinity and water temp areas.
Next you need to know what the existing antifoul is in terms of Hard, or Ablative. Hard will not work if painted over ablative, but the reverse will.

Ablative will peel at edges, so as a minimum, it needs a "wet sand". Wet, because that is what stops the dust and makes it sad to do, although you still need the overall, gloves, mask and eye protection - as several have said above here, it is toxic stuff.
Europeans are actually considering banning amateur work, they will leave it all to trained "professionals"..Ha, gross overkill we know and the proposed is being objected to.
Years ago, we scraped it off dry and some people often suffered for weeks later. Nowadays we all know better.
There are also some strippers you use where there is a plastic sheet you apply over it, then come back later and it all peels off in one go. May be worth checking that out (sorry, forgot the name)
Roger

[alansmith]

I just spent close to 3 months, there daily, doing my own bottom job on my 30 Sharpie. Lucky for me they were able to invert the boat.

To be perfectly clear there is a world of difference between blasting old stuff off and repainting....yes, I agree, that is not back breaking work. But if you have to get the bottom down to the skinny...yes, that is nasty job. There are hand held machines that will skin it. Trouble is you are working at a very poor angle on the bilge areas. A lot of strength required and endurance when working overhead with your arms.

In the Napa Marina in California when removing anti-foul paints it is required by law to remove it with a vacuum attached sander like a Festool. I never saw anyone stripping with chemical. California is very strict about anti foul removal.

Also I had to giggle when one of C.F. members posted 10 dollars/hour for hired hands to remove paint/apply antifoul. Is it just California that has 100 dollars/hour for shipyard fees?

Wish you luck and please post up how you ended up doing your big boat. That big of a boat...daunting. Hopefully all you will need is a good high pressure hose off, light sand job, and roll on.

[charliehows]

The guy on the waterblaster does a pretty good job of taking most of the crap and barnacles off my hull, I usually spend about an hour following up with a scraper and shes ready for painting. At $200 a day standing fees, waiting for 24 hours for an unnecessary process that removes valuable residual paint seems a little...unwise...lets see $200 extra standing fee, loss of $500 worth of existing antifoul paint and whatever the stripper costs, a good amount of labour cost to work the stripper - you're looking at increasing the cost of your antifouling by at least a couple of thousand dollars. well, whats the worst thing that can happen if you use the wrong product? osmosis promotion, or a hole in the hull. I'm looking for any advantages to this idea....

[KWISPEL]

I did it also 1 time and it damaged even te gelcoat!
Use it first on a small spot and leave it for a long time. If it damage the gelcoat than the product will make small holes in the gelcoat, even if you don't see them.
I love sanding with a small machine and a vacuum cleaner. Scraping is also ok if you sand it on the end.

Other people have maybe a other opinion.

[Sailor647]

We took off several coats of ablative and a coat of the hard bottom paint (that was underneath the ablative) in order to repair the blisters on our Norseman 400 and add fresh hard anti-fouling paint. (Trinidad Pro SR) We did all the work ourselves in the yard at Astoria Oregon. We used an orbital sander attached to a vacuum to remove all the old paint. Yes, it was hard work. But, three years later, it's still there. And we saved a LOT of money.