Richard Peter Posted April 21, 2014 Report Share Posted April 21, 2014 I always use epoxy for all things boat...Nothing is more waterproof or stronger. My experience with epoxy has only been with the 5 minute variety and I think it would be too weak so I'm guessing you are refering to a different kind. What are you using for your boats? Anyone else using an epoxy? I can see the mixing to be a bit of an added process but if it is truely water proof and limits the creep it could be worth exploring. Then again if you look at how long some of Jeff's boats have held up without epoxy (long live Long Shot!) is it realy necessary. Is it a good-better-best situation with Jeff having good and Hirilonde having best? Quote Link to comment Share on other sites More sharing options...
Hirilonde Posted April 21, 2014 Report Share Posted April 21, 2014 I use West System, but there are many good brands of epoxy. Raka, System 3, Total Boat, the list goes on. Resorcinol, another 2 part glue is superb too, but it is purple. I will let everyone decide for themselves what good enough is. Quote Link to comment Share on other sites More sharing options...
Action Tiger Posted April 22, 2014 Report Share Posted April 22, 2014 I don't know how to do the quote thing, but I agree with Hirilonde about scarfs. I would only ever do a mechanical scarf because I like to torture myself. I also enjoy complicated joinery. Plus, they only really belong on a full-blown nerdy copy of an old boat. Glued scarfs are simpler and better, in every respect. An original builder would have glued, were that an option. Cut a nice long scarf, glue it well on both sides, clamp it well. I use Raka... I have never boiled one of my boats. Quote Link to comment Share on other sites More sharing options...
Kudzu Posted April 22, 2014 Report Share Posted April 22, 2014 ...... Is it a good-better-best situation with Jeff having good and Hirilonde having best? I think it "it works" or "It doesn't work" is all that is necessary. Epoxy is more waterproof/Titebond joints don't fail, so which is better? All that matters is the joint doesn't fail so I don't see one being better than the other. Quote Link to comment Share on other sites More sharing options...
CapecodJohn Posted April 22, 2014 Report Share Posted April 22, 2014 for what it's worth - I put all my scarfs under the lashings Quote Link to comment Share on other sites More sharing options...
Richard Peter Posted April 22, 2014 Report Share Posted April 22, 2014 Great feedback! Thank you all for sharing your wisdom with a complete SOF Newbie! Quote Link to comment Share on other sites More sharing options...
msaxton Posted April 22, 2014 Report Share Posted April 22, 2014 Ok, I'm missing something, what are people talking about pertaining to "boiling the boat" ?!?! Quote Link to comment Share on other sites More sharing options...
Action Tiger Posted April 22, 2014 Report Share Posted April 22, 2014 The standard that truly waterproof, as opposed to water resistant, adhesives tolerate boiling for a specified period of time. A boat builder joke. Quote Link to comment Share on other sites More sharing options...
msaxton Posted April 22, 2014 Report Share Posted April 22, 2014 Wow, parted my hair on it's way over my head, LOL Quote Link to comment Share on other sites More sharing options...
PAR Posted April 23, 2014 Report Share Posted April 23, 2014 Actually there are a few adhesive (and glues) that pass the "type 1" WBP test. TiteBond III passes this test, but this test is flawed and TiteBond III just barely passes, because of the way it's conducted. Epoxies can be formulated to pass this test too, but the "usual suspects" of retail available, marine grade epoxies don't. This simply means you shouldn't anchor your wood/epoxy yacht over active underwater volcanoes, but other wise is a poor indication of real "waterproofness". The only thing a scarf should do is make a couple of smaller pieces act (pretty much) as a single larger piece might. There are practical, mostly obvious reasons for this, but when joined, the pieces should have similar bending, tension, compressive, etc. properties as a single piece of the same dimensions. Lashings will defeat the point of using a scarf and most any joint will do in this case, preferably one that accepts movement better than a scarf, such as a self aligning and/or self capturing type of joint. 5 minute epoxies are real compromises in physical properties, because of the cure time requirement. They're about useless on a boat, unless you need to stick a broken countertop fiddle back on or similar. 1 Quote Link to comment Share on other sites More sharing options...
Clintopher Posted April 24, 2014 Report Share Posted April 24, 2014 I've never used epoxy and I have little experience with boatbuilding but I know a thing or two about tightbond 3. I used to build laminated longbows and used tb3 to glue the laminations. I'm no engineer but my best guess is the compression and tension loads on a bow limb far surpass what a boat framing member would ever see before breaking. I never had a bow fail. I did switch to a 2 part glue but only because it increased the time available before the glue set up. The bows were always dry though. Keeping them damp for a couple hours could change everything. 1 Quote Link to comment Share on other sites More sharing options...
Richard Peter Posted April 24, 2014 Report Share Posted April 24, 2014 That's good to know. I'm leaning towards TB3 because there are many positive comments on this forum. That's not to knock epoxy but the quality of the product and the ease of use makes it ideal for my needs. Quote Link to comment Share on other sites More sharing options...
PAR Posted April 24, 2014 Report Share Posted April 24, 2014 Again TiteBond III has it's uses, but in wet structural applications, there are better choices. Even TiteBond admits it should be used in structural applications. As to laminated bows, well the loads on certain boat parts will greatly exceed anything a bow could offer. Think of a T foil rudder blade or the arm connections on an ama or catamaran hull. Granted a bow will have considerable dynamic loading, but it's cyclic rate isn't very high, while a high performance boat's parts might have hundreds of cyclic loads an hour, or in the case of a race boat I designed that's firing up for a new season, hundreds of cyclic loads per minute. Quote Link to comment Share on other sites More sharing options...
Clintopher Posted May 3, 2014 Report Share Posted May 3, 2014 Again TiteBond III has it's uses, but in wet structural applications, there are better choices. Even TiteBond admits it should be used in structural applications. As to laminated bows, well the loads on certain boat parts will greatly exceed anything a bow could offer. Think of a T foil rudder blade or the arm connections on an ama or catamaran hull. Granted a bow will have considerable dynamic loading, but it's cyclic rate isn't very high, while a high performance boat's parts might have hundreds of cyclic loads an hour, or in the case of a race boat I designed that's firing up for a new season, hundreds of cyclic loads per minute. An excellent point. I didn't have sailing forces or multihull boats in mind when I put my two cents in...was thinking about monohull paddle/rowing craft. 1 Quote Link to comment Share on other sites More sharing options...
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