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Thread: Removing paint from inside of hull?

  1. #1
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    Default Removing paint from inside of hull?

    I've got a 17' dory that has white paint on the inside. It's not real thick. Anyway, I'd like to remove it and apply varnish. I'm not sure that makes sense, but how would I do it?

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    Default Re: Removing paint from inside of hull?

    Quote Originally Posted by overland View Post
    I've got a 17' dory that has white paint on the inside. It's not real thick. Anyway, I'd like to remove it and apply varnish. I'm not sure that makes sense, but how would I do it?
    Unless there was varnish applied before the paint, it's likely a bad idea. A lot of work for a mediocre result. The paint tends to stay tenaciously in the pores, and leave you with a 'speckled' result. Unless everything is solid timber, where sanding will work and not burn thru the face veneer of some plywood. LOTS of work.

    The two main avenues for paint removal are -- 1. chemical strippers and scraper & scrubby. 2. Heat (typically a heatgun) and scraper/scrubby.

    I'd skip it.
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  3. #3
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    Default Re: Removing paint from inside of hull?

    I think there was epoxy applied before the paint. Does that change your advice?

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    Default Re: Removing paint from inside of hull?

    Quote Originally Posted by overland View Post
    I think there was epoxy applied before the paint. Does that change your advice?
    Don't use heat, it will strip the 'poxy. Use chemicals, with all the PPE that requires. Do not sand through the epoxy, or the varnish will dry patchy.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Removing paint from inside of hull?

    What Dave G says
    -Dave

  6. #6
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    Default Re: Removing paint from inside of hull?

    Apologies for this being dangerously close to "thread drift", but what treatment would be recommended for the inside of a 70-yr-old Old Town canoe that was varnished inside but is now largely worn weathered cedar and ash?

  7. #7
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    Default Re: Removing paint from inside of hull?

    Overland... If you're really wanting to do this, then the only way you'll know how much work it is and if it can be done, is to try it. Get yourself some chemical stripper and use it on an area of the boat. How this trial turns out will guide you to your next step. No amount of advice here or elsewhere can substitute.

    Jeff

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    Default Re: Removing paint from inside of hull?

    Overland-
    Try Jeff's advice and then scuff-sand the rest of the interior and paint it something more pleasing.

    Recently I've been painting over some badly sun-damaged brightwork with #41 Spar Buff. I think it is nice medium, not so brown as to be trying to fool anybody but not a bright yellow either.

    The flats are relatively easy to strip, it will be the corners that cause most of the suffering. IF you are insistent about stripping the white paint out, do it next winter when you have time to do it bit by boring bit not as part of your spring fit-out.
    Steve

    If you would have a good boat, be a good guy when you build her - honest, careful, patient, strong.
    H.A. Calahan

  9. #9
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    Default Re: Removing paint from inside of hull?

    I wonder how a pressure washer would work in this application, with softer paint over harder epoxy substrate? Possibly first applying paint remover then taking that off with a pressure washer. Obviously a light touch is required. I have a cheap electric model and use it often.

  10. #10
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    Default Re: Removing paint from inside of hull?

    Quote Originally Posted by jpatrick View Post
    Overland... If you're really wanting to do this, then the only way you'll know how much work it is and if it can be done, is to try it. Get yourself some chemical stripper and use it on an area of the boat. How this trial turns out will guide you to your next step. No amount of advice here or elsewhere can substitute.

    Jeff
    If you decide to strip, know that some chemical strippers will also attack the epoxy. Some will not be sure to get the latter.
    David G
    Harbor Woodworks
    https://www.facebook.com/HarborWoodworks/

    "It was a Sunday morning and Goddard gave thanks that there were still places where one could worship in temples not made by human hands." -- L. F. Herreshoff (The Compleat Cruiser)

  11. #11
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    Default Re: Removing paint from inside of hull?

    Quote Originally Posted by Nicholas Scheuer View Post
    Apologies for this being dangerously close to "thread drift", but what treatment would be recommended for the inside of a 70-yr-old Old Town canoe that was varnished inside but is now largely worn weathered cedar and ash?
    Sand it with 120 and give it a coat of thinned varnish.
    Sand with 240 between coats and give it 2-3-coats full strength.
    Varnish not poly.
    Coat it every couple of years as routine maintenance.

  12. #12
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    Default Re: Removing paint from inside of hull?

    As David points out; the dory.... You will never get all the white paint out of there, and it will look, well, not so good. Clean it, Scrape it, and Sanding and/or Scotchbrite pads for a good "tooth" and repaint it. Starting perhaps with a primer coat.

    For the cedar canoe I would clean it well with soap and water, then an oxalic acid wash to beach the darkened places where the varnish was missing, then after it has dried out for a couple weeks, what Chris said, then back to a varnish routine. Scrotchbrite pads work well enough for me to scuff up the varnish for another coat. I buy those things by the box!
    For most varnish work you want a "blocked" surface between coats Scotchbrite pads do not work because they follow every high and hollow rather than "leveling" them. But a cedar canoe has a million clenched tacks and all the leveling work is a waste of time, except on thwarts/rails etc. A file sharpened scraper is my go-to for the first cut.

  13. #13
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    Default Re: Removing paint from inside of hull?

    I just sanding the interior or my Sea Skiff and you will need a calendar, not a clock to keep up with all the time it will take.

    I found that a multi-tool with a sanding pad was perfect for the job. It was the only thing that would do a good job but I spent days and days sanding this one. And I was just trying to remove the old flaking paint to get it ready to paint again. Can not imagine trying to get back to bare wood.

    Try a small spot but I think you will find it is not worth it!

    Jeff
    Kudzu Craft Skin boats
    SoF boat kits, supplies and plans

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