removing marine epoxy... etc

Discussion in 'Wooden Boat Building and Restoration' started by gforcepdx, Nov 19, 2006.

  1. gforcepdx
    Joined: Nov 2006
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    Location: portland oregon

    gforcepdx Junior Member

    help folks... this is my first post...i am getting a boat... aluminum hull, marine plywood top... the plywood is covered with a thin layer of fiberglass and then painted... problem is, the guy botched the 2 part marine epoxy and it never fully cured... wherever their are runs in the paint... and there are many... you can pick them off with a fingernail... worse yet, when washing the decks it leaves a grey film in the red hull paint... i am afraid to even think about the condition of the hull paint at this point... so... it is cracking at some of the seams in the plywood [not sure what is causing that] and is simply letting water pass through at other points... nothing bad yet... but i am thinking the only fix for this is to completely remove the gummy top coat of marine paint... repair any nessary fiberglass work and then do a proper job of the marine epoxy... i am afraid to paint over the existing unstable paint [its not that bad... just not stiff like it should be]... though this would be the easy way out... the new paint would bond to the old stuff... but it sounds like good money after bad to me... so i think i need to remove the paint from a 41'x13'5'' plywood topped sailboat and do it without messing up the fiberglass sublayer [except for where the glass is damaged and needs to come up anyway]... i figure i can use a heat gun where the glass is bad but what about the rest... jasco stripper ??? does it damage fiberglass ??? i have looked it up on there website and they make no mention of this senerio... also... i have never owned a plywood boat.... can anyone tell me..... is the splitting at the seams just the price you pay for this type of construction ??? i am thinking that part of the job of the glass is to help stabilize seams and corners as well as provide added protection to the ply... i have worked with wood in the past but i have no experience with marine applications... thank you all and happy sailing..... j
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    You seem to have a few different troubles. One simple issue to fix, is the likelihood of blush being present when the boat was painted, after the 'glass work. If the blush wasn't removed, it will cause problems with paint adhesion and cure (you may have both difficulties). The fix is to remove the paint, sanding down until you reach the intact 'glass work and prep for paint again.

    Other issues may include wrong epoxy/hardener ratio mixture, which will never cure and is not good for anything. It has to come off, the surface prepped again and the 'glass or epoxy job done correctly, so the goo will fully cure and the paint will stick.

    Unfortunately, there are no simple answers, you have to remove the bad stuff, by the least damaging means and start the process on fresh wood or intact 'glassed surfaces. Heat can help, so can some types of strippers, but the successful use depends a lot on how familiar you are with using them.

    Cracked seams, runs, paint that isn't sticking well and the rest are examples of a poorly done repair or construction. They don't have to be typical of the type or method. It's probable, that you'll have to grind back to raw wood in most places, just to insure you have a solid, clean bond with the plywood. Yep, this means doing the 'glass work over, but you will not be guessing at the results or what's underneath anymore.

    The site has many previous threads on this subject and other similar repairs. Use the search thingie to look up a few of these and read up on other's efforts.
     
  3. gforcepdx
    Joined: Nov 2006
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    Location: portland oregon

    gforcepdx Junior Member

    you have confirmed what i suspected... the good news in all this is that the fellow who did the painting had nothing to do with the glass or ply work... the boat was professionaly built and until a few years ago had a nice paint job.... the bulk of the job i have ahead of me is simply striping the paint from the intact glass work... a stripper [jasco] SEEMS like the fastest and simplest way to remove the goo... sand paper sounds cheaper but more work... but can you tell me if the stripper will have any ill effects on the fiberglass ??? i'm guessing no... but i can not find any text saying so and have never tried it myself... i will do more reading but everything i have seen so far talks mostly about sanding..... thank you for the response..... j
     
  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    If the stripper doesn't say fiberglass safe on the label, it will attack the 'glass work, possibly ruining it for future coatings. Use a 'glass safe stripper. Sanding is the safe way to do it and it also tends to smooth the surface defects, which likely will need attention anyway. With the proper tools (sanders) you can remove the paint pretty quickly. Stripper may get a bunch of it, but you'll have plenty of sanding to do later.
     
  5. gforcepdx
    Joined: Nov 2006
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    gforcepdx Junior Member

    yes i figured that there would be sanding involved... but i have never gone up against epoxy paint befor... and this is worse yet as it is mildly gummy in nature... i had visions of sanding for 40 seconds and then 2 minutes to change the paper because the gummy nature of the paint would stick to the grit... i have had a similar experience removing oil base paint from hardwood floors and found that a stripper made from a 50/50 mix of deisel and motor oil was VERY effective in removing the paint that had privously clogged the sander grit and forced paper changes every 40 seconds... VERY maddening... but i have never worked with marine epoxy... which sounds VERY hard... except that this is a bad application and so i am expecting the gum up factor... but i really don't know... like everything else you do for the first time ... by the end of the job you become an expert... i'm just looking for pointers to start from... thank you for the input on the stripper... i went to the website of the manufacture for guidence but their was no mention of fiberglass applications... ether pro or con... i will call them monday and get the skinny... so do you still think that sanding is the fastest and most effictive method for removal ??? if i were to go that route i was thinking of getting a JITTER BUG sander that runs on compressed air and do a wet sanding like they would do in a body shop... to keep the dust down... and it seems to work well as apposed to a standard vibrating sander.... i guess i figured that a stripping gell would go pretty quickly... what do you think ... thanks..... j
     
  6. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Jitter bugs are finish sanders, not really intended for bulk material removal. You need a grinder. A standard 7" is pretty common and I have two, but my 10" kicks butt and will rip your arms off if you don't have a firm grip too.

    Yes, gummy materials are a pain, but sanding speed with power tools can help this a lot. Often times you'll get gummy results very quickly if you sand too long in one area, which heats the material until it's soft and gummy. Moving around helps, but controlling the speed of the sander is the best way.

    I have a cheese grater looking sort of disk I can use when I'm pissed at something or generally need to move a lot of material. It will carve right through a piece of 1 by stock in a minute. It loads up with material, but it can be removed and blown clean pretty easily. It will really hack up a surface, so you have to want to hurt something for this tool.

    Try the stripper. At least you'll get a dent in the coating, where sanding afterward will be less difficult. The gummy factor, sometimes is a fact of life. You can use a heat gun and scrapper too, which is the traditional way of removing paint. If you're still of breeding age, then protect yourself, or you can have three headed babies later in life.

    Test the stripper in a small area first. Follow the instructions and let the goo do it's job. Once it's washed off, closely examine the 'glass. If it looks grazed, pitted or otherwise damaged, you'll need to get some 'glass safe stripper. West Marine and other outfits sell 'glass safe stripper so, you probably better being safe then sorry. Work in reasonably small areas with this stuff. It's easy to get carried away, work too much area and have the stuff dry on you, getting no work done.
     
  7. gforcepdx
    Joined: Nov 2006
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    Location: portland oregon

    gforcepdx Junior Member

    thank you for the input... i have foung a fiberglass safe stripper... it sounds to me as though you would do the whole thing with a large sander... do you really think that would be the fastest way ??? i'm all about power tools if it speeds things along... in fact i may have a 10 inch in the basement... i think i'll leave the cheese grater thing to you... what do you think..... j
     

  8. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Use the stripper, it's safer then a grinder. A grinder can easily remove way more material then you want to in short order. The stripper will not eat up sand paper, like it's a clearance sale at Wal-Mart and you'll have plenty of time with the grinder after the stripper has done it's deed.
     
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