commercial crossplanked deadrise workboat bottom compound caulkgun

Discussion in 'Wooden Boat Building and Restoration' started by marsh trapper, Feb 17, 2015.

  1. marsh trapper
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    marsh trapper Junior Member

    Hey I have a 1965 built maryland workboat white cedar over oak frames .my question is what to use for between her bottom plank seams on top of the cotton caulking ive heard of portland cement roofing tar and neoprene roof tar....I should mention I want to use a tar or roof type compound that I can use with a caulk gun...I dont want to use 5200 4200 ive heard bad stories on crossplanked workboat s and im tired of using a putty knife..thanks
     
  2. gonzo
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    gonzo Senior Member

    Roofing tar works fine in the bottom. It will stain over any paint, so black antifouling is required. Putty made of raw linseed oil and a filler is another typical mix.
     
  3. marsh trapper
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    marsh trapper Junior Member

    What typ roofing tar or tar cement tho
     
  4. gonzo
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    gonzo Senior Member

    I have been successful using the wet/dry patch material. It adheres on wet surfaces and some contamination.
     
  5. marsh trapper
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    marsh trapper Junior Member

    What brand /type and did u use it before launch
     
  6. gonzo
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    gonzo Senior Member

    Henry has worked well. Ace hardware had their own brand. It was OK, but seem not to be as sticky.
     
  7. marsh trapper
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    marsh trapper Junior Member

    Is that what some people on forums reffer to as bear shi* ?
     
  8. gonzo
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    gonzo Senior Member

    Not sure :)
     
  9. SaugatuckWB
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    SaugatuckWB Junior Member

    Bear sh:t

    That's what tar for bedding compound is called. For seams I only used it once and an old fisherman (who was in charge of the mess) mixed it with cement (50/50 ish). You can't get that in a tube. Some say mix bottom paint in too, but I've no experience with that. Jetcoat works good for bedding and takes paint, but bleeds through occasionally in places where it gets lots of sun (heat).
     
  10. PAR
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    PAR Yacht Designer/Builder

    There are two types of "roofing tar", one is petroleum and the other asphalt based. The asphalt base can be painted over by some paints, but the petroleum stuff.

    BearShit is an adhesive/sealant, usually brownish black, which isn't anything like MonkeyShit which is a darker yellowish color. MonkeyShit is used on rubber gaskets, seals and the like, while BearShit is used on harder items and tends to dry with much less elasticity, compared to MonkeyShit. There are many "home brews" of these two concoctions, but most are now using commercially available polyurethanes, polysulfides or the older school butyl rubber formulations. The butyl rubber concoctions are often also called BearShit too. Now, lets see if Jeff catches all the animal dung references . . .

    If you use roofing tar, some success can be had with aluminum aerosol paint (poor mans chrome), to prime the area for a topcoat.
     
  11. whitepointer23

    whitepointer23 Previous Member

    So for a really big area do you use elephantshit
     
  12. Mr Efficiency
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    Mr Efficiency Senior Member

    I once took a broken metal fitting to a repair shop, and the bloke offered the opinion it was probably "shitmetal", which I can't find in the dictionary.
     
  13. PAR
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    PAR Yacht Designer/Builder

    Don't know about the elephantshit stuff, but shitmetal is usually "pot metal" and really hard to weld. In fact, it's usually only possible to braze this stuff and it's a marginal attachment at best.
     
  14. Mr Efficiency
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    Mr Efficiency Senior Member

    That is pretty much what I was told, it was the handle you pull to disengage the tow-ball from the trailer, on an old trailer, that had somehow busted, it was some type of cast metal that was deemed too difficult to weld, and I just got a replacement. The colourful language used was obviously derived from previous experience with failed attempts to get a satisfactory repair! :D
     

  15. PAR
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    PAR Yacht Designer/Builder

    I've had some limited success brazing pot metal, but getting the heat right is a prick. If you get it hot enough to stick the rod, the pot metal usually breaks down, not hot enough and the rod doesn't flow. Pot metal seems to be a fine metal powder glued together with elephantshit, which doesn't take to heat well.
     
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