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Thread: Bottom paint removal

  1. #1
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    Default Bottom paint removal

    Many, many layers. I really need to get all this loose crap off the bottom of the hull. I’m using a Festool DA sander. It works, but It’s SLOW. Need something more aggressive. What’s the weapon of choice?
    Fight Entropy, build a wooden boat!

  2. #2
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    Default Re: Bottom paint removal

    Which festool are you using ?
    Or, One might sail the boat to the Caribbean and disc sand it .
    bruce

  3. #3
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    Default Re: Bottom paint removal

    It’s not the Rotex, Single mode DA. I think it’s the 125.
    Fight Entropy, build a wooden boat!

  4. #4
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    Default Re: Bottom paint removal

    Quote Originally Posted by wizbang 13 View Post
    Which festool are you using ?
    Or, One might sail the boat to the Caribbean and disc sand it .
    bruce
    I thought Dudley crossed the bar. You mean he’s just hanging on a beach in the Caribbean?

  5. #5
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    Default Re: Bottom paint removal

    you can try using stripper. it is very good. it may be better than sanding. do a section at a time. it may be cleaner and safer than using sanding. possibly better for environment as you can take the removed paint to proper recycle rather than toss the paint dust into the trash.

    A large nose is the mark of a witty, courteous, affable, generous and liberal man. My feature suggests an excellent side kick of good index.

  6. #6
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    Default Re: Bottom paint removal

    There are four primary options I've used.

    1. Abrasives - a big spinner is faster than a R.O. sander

    2. Stripper - I tarp under with cheapo tarps, and dispose of the whole mess as industrial waste

    3. Blasting - Not sand... too aggressive. Consult your local expert for their recommendation

    4. Heat gun + scraper - tedious, but the least dramatically messy

    They each have their place... depending on the circumstances. Ablative/non-ablative. Strictness of local regulations. Tools on hand vs. buying a new toy. Budget - DIY vs. hire it done.
    David G
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  7. #7
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    Default Re: Bottom paint removal

    I use ablative paints. I like a properly sharpened scraper, giving the edge a couple of swipes with a single cut fine mill file to sharpen and slightly curl the edge. I don't press too hard because I'm lazy and like to let the tool do the work.

    A big advantage of scraping is that the flakes are mostly heavy enough to fall to the drop cloth so you're not getting toxic dust into the environment and all over yourself.

  8. #8
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    Default Re: Bottom paint removal

    The Rotex has a switch that makes the wee circles quite a bit bigger...much more aggressive.
    A finishing sander is not up to par.

    Ron, I was never as strong or fast as Dudley, but disc sanding was how I paid for my lifestyle before I got lucky with art,(Bahama Breeze restaurants).


    Of course we cannot make a puff of dust in a boatyard, and disc sanding can do some damage.
    So, I'd recommend the Rotex. ....and NEVER let it build up again !

  9. #9
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    Default Re: Bottom paint removal

    Dry ice blasting can take all of that bottom paint off, right down to bare wood, without any damage to the wood itself! The dry ice CO2 evaporates leaving only the paint dust to be vacuumed up. Rigs can be rented. Your boat might take an hour per side to strip.
    Jay

  10. #10
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    Default Re: Bottom paint removal

    Quote Originally Posted by Ian McColgin View Post
    I use ablative paints. I like a properly sharpened scraper, giving the edge a couple of swipes with a single cut fine mill file to sharpen and slightly curl the edge. I don't press too hard because I'm lazy and like to let the tool do the work.

    A big advantage of scraping is that the flakes are mostly heavy enough to fall to the drop cloth so you're not getting toxic dust into the environment and all over yourself.
    I agree with Ian. A "properly sharpened scraper" does a great job. I've done many bottom jobs on both wood and fiberglass boats using mostly scrapers. A good scraper is surprisingly fast and very effective and there's almost no dust!

    I remember meeting Dudley once or twice in my career. He was a real character. I also worked alongside his successor, "the big Irishman with the size 46 jacket and the size 5 hat" as Dudley once said. Both men were good people but dusty...

  11. #11
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    Default Re: Bottom paint removal

    Red Devil scraper and a whole stack of pre-sharpened blades plus a heat gun works, but it's still a chore, and it's awkward and easy to burn yourself holding the heat gun in one hand and the scraper in the other.

    Can you flip the hull over and use a belt sander with 40 grit? When the paper plugs clean it up with a wire brush.


  12. #12
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  13. #13
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    Default Re: Bottom paint removal

    Having scraped and sanded my share of bottoms, and even for this DIY forum, hire a blaster service.

    Kevin
    There are two kinds of boaters: those who have run aground, and those who lie about it.

  14. #14
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    Default Re: Bottom paint removal

    My first choice would be dry ice. Second choice would be Peel Away.

    https://dumondchemicals.com/home-peel-away-1.html
    Heute ist so ein schöne Tag...

  15. #15
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    Default Bottom paint removal

    Propane torch with a flame spreader and a scraper. Fast. Quiet. No toxic dust.


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  16. #16
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    Default Re: Bottom paint removal

    Quote Originally Posted by Gib Etheridge View Post
    Can you flip the hull over and use a belt sander with 40 grit? When the paper plugs clean it up with a wire brush.
    Heck if you can roll it over to make various areas walkable and sorta horizontal hire a hardwood floor stripper/resurfacer

    Edit: BTW I've used those wire flail rotostripper things on external woodwork before, and they can work, but some tips, patience, don't lean on them, once you bend the wires they don't work so well. Also they go blunt after an hour or so, so to touch them up you can run them in reverse and touch them on a concrete or stone surface to sharpen up the ends... carefully.
    Last edited by Plyboy; 06-30-2019 at 06:54 PM.
    2019: returning from being sidelined with medical probs, crossing fingers worst is over, still in "armchair enthusiast" mode for time being.

  17. #17
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    Default Re: Bottom paint removal

    Take it to a yard and throw money at it.

  18. #18
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    Default Re: Bottom paint removal

    Quote Originally Posted by Plyboy View Post
    Heck if you can roll it over to make various areas walkable and sorta horizontal hire a hardwood floor stripper/resurfacer

    Edit: BTW I've used those wire flail rotostripper things on external woodwork before, and they can work, but some tips, patience, don't lean on them, once you bend the wires they don't work so well. Also they go blunt after an hour or so, so to touch them up you can run them in reverse and touch them on a concrete or stone surface to sharpen up the ends... carefully.
    You would have a floor refinisher touch a boats planking?

  19. #19
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    Default Re: Bottom paint removal

    Everybody has forgotten the key, the only vital ingredient should you embark on this very tough job!

    Ibuprophen.

    CO2 blast for sure next time I must do it.

  20. #20
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    Default Re: Bottom paint removal

    Having mostly stripped one side of a fat 39' ketch two years ago, here's my 2c:
    I tried a variety of strippers, some worked partially, some hardly at all. The bottom has a variety of old paints on it.
    Sanders are brutal, can damage the surface, tire you out, create nasty dust in spite of vacuums. I did use one to smooth out after rough removal.
    Heat also varies in effectiveness on different formulas. Dried paint benefits from a dose of linseed oil, which will soak in and bubble when heated. I used an assortment of scrapers, but mostly two expensive carbide ones with shaped edges. For heat I also used different tools, a mid priced heat gun and an expensive infrared. The infrared worked better except when it was cold and windy.
    A sandblast guy thought he could do it. He previously did two wooden boats. But those were teak and mahogany, mine is cedar. The paint is harder than the wood. I don't believe he tried dry ice, but maybe soda.
    In the end I found heat and scrapers best. Good luck, keep us posted.

  21. #21
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    Default Re: Bottom paint removal

    Quote Originally Posted by wizbang 13 View Post
    You would have a floor refinisher touch a boats planking?
    Sure, one pass at a flying sprint can get your cedar strip guide boat down to an ultra portagable 15lb.... well you don't have to use the roughest grit, depends what sort of accumulated armor plating you're tryna break through, and how soft a wood is underneath. I guess I'm more thinking of the disk sander on a dolly type where you have some control over the pressure rather than an inverted power planer or belt sander on a stick type that are 4x as heavy solid cast behemoths and take a quarter inch a pass and dig through to the basement if you pause for 2 seconds.
    2019: returning from being sidelined with medical probs, crossing fingers worst is over, still in "armchair enthusiast" mode for time being.

  22. #22
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    I used Soy-Strip and was very pleased. Removed what had to have been at least 6 layers. Non-toxic too.

    Ken


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  23. #23
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    Default Re: Bottom paint removal

    Peel away does a great job but its labor intensive smearing that stuff on and its no picnic cleaning up. No dust, toss eveything when youre done, be patient.....

  24. #24
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    Default Re: Bottom paint removal

    On a personal note:

    I was busted this morning because yesterday I was lightly sanding the topsides of the hull without a fein vacuum machine in the yard. I used a fine multi master to knock orange peel and prep for a new coat of white paint. Here we are no longer allowed to use long freely board either. I feel quite guilty. I have to go in person to repent. The yard is pretty angry as watchdog groups and fellow folks in the yard saw me. Leaving dust in the garbage bin was equally bad.

    I learned my lesson. Hopefully others will learn from my error too.
    Last edited by Ted Hoppe; 07-01-2019 at 01:47 PM.
    A large nose is the mark of a witty, courteous, affable, generous and liberal man. My feature suggests an excellent side kick of good index.

  25. #25
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    Default Re: Bottom paint removal

    Gonna try the torch and scraper method presented by OCH. I bought a good respirator.
    If this doesn’t work I’m gonna spring for the Festool Rotex 150. I just sold my convertible on Bring a Trailer so I figure I can treat myself.
    I will say that the thought of using heat to scrape the bottom of the catboat when the heat index is 104 is a bit daunting.
    Fight Entropy, build a wooden boat!

  26. #26
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    Default Re: Bottom paint removal

    OK, the torch and scraper method is FAR superior to sanding. I got about 1/2 the peers side done in maybe 90 minutes this afternoon. No dust, and the scrapings are an easy cleanup.
    Hit it with the DA Festool with 100 grit afterwards and it leaves a nice surface. A couple 3 more of the little propane cylinders and I think I can have it wooded. There was SO much buildup on the bottom it really needed to be done seemed like almost 1/8” in places.
    Thanks to everyone for the suggestions. A cold beer and the outdoor shower were a great reward after that stint on a 100 degree day.
    Fight Entropy, build a wooden boat!

  27. #27
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    Default Re: Bottom paint removal

    Glad to hear that OCH video was a help!

  28. #28
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    Default Re: Bottom paint removal

    Quote Originally Posted by rbgarr View Post
    Glad to hear that OCH video was a help!

    It absolutely was,thanks.
    Fight Entropy, build a wooden boat!

  29. #29
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    Default Re: Bottom paint removal

    Quote Originally Posted by Reynard38 View Post
    OK, the torch and scraper method is FAR superior to sanding. I got about 1/2 the peers side done in maybe 90 minutes this afternoon. No dust, and the scrapings are an easy cleanup.
    Hit it with the DA Festool with 100 grit afterwards and it leaves a nice surface. A couple 3 more of the little propane cylinders and I think I can have it wooded. There was SO much buildup on the bottom it really needed to be done seemed like almost 1/8” in places.
    Thanks to everyone for the suggestions. A cold beer and the outdoor shower were a great reward after that stint on a 100 degree day.
    I am well acquainted with the heat here - just a reminder for all - stay hydrated when working in these conditions !!!

  30. #30
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    Default Re: Bottom paint removal

    Quote Originally Posted by Reynard38 View Post
    A cold beer and the outdoor shower were a great reward after that stint on a 100 degree day.
    Use one of these for hands-free, safe, hydrated work under there. And if you do it in the nude, no sweated-up clothes-washing necessary and you can step right into your outdoor shower unimpeded. Photos needed of course....

    https://www.amazon.com/EZ-DRINKER-Be...04725427&psc=1

  31. #31
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    Quote Originally Posted by Ted Hoppe View Post
    On a personal note:

    I was busted this morning because yesterday I was lightly sanding the topsides of the hull without a fein vacuum machine in the yard. I used a fine multi master to knock orange peel and prep for a new coat of white paint. Here we are no longer allowed to use long freely board either. I feel quite guilty. I have to go in person to repent. The yard is pretty angry as watchdog groups and fellow folks in the yard saw me. Leaving dust in the garbage bin was equally bad.

    I learned my lesson. Hopefully others will learn from my error too.
    Soon all maintenance will be illegal. You probably scrubbed more rubber off your tyres on the way to the yard than the paint dust you took off your boat. And where does that tyre dust end up?

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  32. #32
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    Default Re: Bottom paint removal

    Well, I hear we are going to aim towards flying cars soon! That should cut way back on rubber dust from tires.

    By the way, dry ice powder blasting was first introduced for stripping paint form structures like bridges houses and commercial buildings. It works so well that most of the former problems involved with damage to wooden structures from water, sand and soda blasting is now a thing of the past! We plan to strip the creosote from the inside of our chimney with it as there is little mess to deal with afterwards other than dust that can be sucked up with a vacuum.
    Jay

  33. #33
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    Default Re: Bottom paint removal

    Coarse P16 sanding disc on a variable speed grinder





    tented hull




    positive pressure dust protection









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  34. #34
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    Greg is that just an ordinary grinding disc holder thinghy? Sometimes hard to find but I use a slightly flexible rubber backing piece and a screw down which sits flat. Makes it easier to get the disc at a nice shy angle.

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