Rotomolded yellow plastic is starting to look good...

[Railmeat]

Just venting here.....

I am in the process of building the Penobscot 14. I'm at the stage where I'm putting the longitudinal stringers over the frames and bulkheads. These are 3/4" square, scarfed to about 16' long. Three down, seven more to hang. Well last night, I went to continue hanging them, but I hit a major problem when I snapped 4 of them one after another. They all broke at the scarfs, which leads me to conclude: (1) I should have just paid the extra money for WEST system epoxy, rather than this Everstar stuff, (2) I should have clamped them better, perhaps even thrown a screw in each to hold the joints while the epoxy set, and (3) I should have grown a third hand prior to gluing everything so I could juggle stringers, glue, and clamps better when the time came.

Frustrating.

[Art Read]

Hmmm... I had a similar problem when I installed my second sheer clamp. But I was able to conclude it was the wood I used. Less expensive, kiln dried fir as opposed to the good, air dried "boat" fir I used on the other side. Couple of questions... Did the failure happen at the joint or in the wood itself? If the joint failed, the problem IS with your epoxy somehow. Either too much clamping and a glue "starved" joint, improper mixing and/or ratio of resin and hardener, not fully cured before you stressed it or crap epoxy. What changed between these failures and the previous successes? More severe bend? Different brand of goop? Nothing? If it was the wood itself that failed, it sounds like you're trying to bend it more than it wants to go. Can you place the scarf at a different location and steam the "problem" area a bit before bending it in there? If not, maybe you just need to try a species that "likes" bending more. Look at it this way... Aren't you glad it "let you know" that something wasn't "right" NOW, while you can fix it, rather than after she's all done and you're pounding home across some nasty chop someday? Ain't boatbuilding fun?

[NormMessinger]

Your guess is better than ours. My bias is that cheap googue is as good as the more expensive in the middle of optimum working conditions but on the margines the extra cost pays off. Why compromise? But some joints you made held and others did not. Why? Were the ones that failed under more stress? Glued at a different time under different conditions? Scarfs that failed planed while those that held sawn?

How can I fail thee? Let me count the ways....

You said you were just venting but tell us more to assuage our curiosity or spark more guesses.

As was noted on a fellows cervical collar, Stuf Happens.

--Norm

[Railmeat]

Well, upon further nvestigation, it's pretty clear that a crappy clamping job is the culprit. I can see from the breaks that only small sections of the scarf joints were bonded, as there was a mix of fractured wood and smooth, flat, fully-cured epoxy where the clamp load was not even. I think the problem was that the two halves of each stringer kept sliding apart as I applied the clamp load. A brad through each would have prevented this, but then we're back to my need for a third hand. The scarfs were sawn, and the halves matched up nicely, though, so I think I can rescue them.

I think when I do the repairs, I'll be more prepared. I'll tack the two halves of each together to prevent the sliding. This is just one of those mistakes that newbies like myself make in what I like to think of as the "discovery" phase of building a boat. As in, I'm discovering how little I know, and that I really need to think things through more carefully ahead of time.

Thanks guys.
Don

[NormMessinger]

There ya go and you're a better man for it. Of Course notihing like that has ever happened to any of the rest of us.

Joy to ya.

--norm

[dcobbett]

Realmeat,

This worked for me a couple of years ago. Used western red cedar (happened to have a couple of boards from another house related project). Cut 3/4" strips, sawed 8" long tapers on one end (dressed the sawn tapers with a block plane or a scraper as required). On an 8' long bench, working alone, laided a stip on its side over a small patch of waxed paper. I clamped the strip down at the end of the bench, applied the expoxy (to both pieces) and slipped them together. I folded the wax paper up on both sides and used 3, 2" spring clamps for each 8" long joint. I pushed both sides of the joint down onto the bench top to make sure the batten was straight in that dimension. I also had a good view of the joint and could make sure the "wedge" faces were not slipping away from each other. When everythhing was O.K., I clamped the other batten down where it passed over the other end of the work bench. I could set up 6 or 8 battens this way across the width of the bench, then I would weight down the group on either side of the splices to make sure they stayed flat to the bench. For me, this solved the working alone issue and I got consistently good resuts (straight, 2 piece, 20' long battens that bent to fair curves) in a short amount of time.