: Hello all,

: Forgive me if this is an amatureish question but last night one of the Scarf
: joints on my "Walrus in embryo" split. It was on one of the
: stringers that has quite a twist and unfortunatly it was located near the
: end of the boat where the twisting was fairly tight. I have been fortunate
: to place the other scarfs around the middle of the boat so they are not
: under such an extreme condition.

: The joint seperated along the glue joint and did not rip out any wood, I was
: using epoxy. I plan to re-glue the joint using epoxy and sister it with a
: wood strip and screws. Unfortunatly now I have no faith in my joints. I
: wonder since it split along the glue joint, maybe I just got a bad batch
: of epoxy. It has been very hot in my work area so maybe the batch went bad
: from the heat. The other thing I wonder is if perhaps I clamped the joint
: to tightly and squeezed all the glue out. Im just using the store bought,
: 2 part syringe type epoxy with a 30 min work time. The directions said not
: to use above 107 degrees and Ive probably exceeded that from time to time
: despite putting a fan on the joints and things like that(Arizona is hot as
: hell this time of year).

: I dont want to go back and sister all of the scarfs on the boat as this is
: sort of unatractive. I was thinking of buying some short screws and
: screwing all of them for extra protection but there is not much meat to
: screw to in a scarf joint.

: Im not sure what to do at this point, I want to be confident in this boat,
: but seeing that broken joint is pretty depressing. I cant imagine trying
: to fix a joint in the end of the boat after it was skinned either, so
: perhaps Im lucky that it broke now.

: Any advice anybody?

: Kirk

Hi Kirk

I also had one joint fail on my Walrus and I know the feeling. I went back and scarfed all the joints with a 3/16" x 3/4" piece about the length of the joint. In the process of twisting the stringers and Chines, I heard two pops as well as the failure. I was using regular yellow glue. I went back and glued the sistered pieces with epoxy ( glass/resin W/wood filler ) and no problems, Don't worry about them showing as none of them should. The top gunwales will be covered by the skin and the Chine joints will be hidden by the floorboards when finished. I feel very confident in my joints now. The only thing that I didn't like was working the trestles where they met the sisters. Just had to trim them a little more..... No biggie!!!

I believe the general consensus is that the store bought tubes of epoxy are not strong enough for use here and I can't remember the theory behind it, but could probably be found in the archives. When we/they epoxy joints it is usually with a small batch of fiberglass resin ( epoxy ) and sawdust or some other filler, mixed to a paste or peanut butter consistancy.

Wet both pieces with a little, leaving about a 1/16" thick patch and then put the pieces together, align, and clamp lightly and don't squeeze all the mix out. Epoxy doesn't adhere the same as yellow glue. What little squeeae out I do get I wipe off with a paper towl to keep the joint looking clean.

The heat in the garage is probably a big contributing factor as well. Epoxy, as I have heard, will soften up with heat. What with the tension you were putting on those joints from the twisting, it probably didn't take much to pop a softened joint.

Were you just trying to twist the strips or using some sort of steam or other heat source? I used some wet towels microwaved to get them hot enough to burn the hands and wrapped the stringers in the area to be bent and twisted. I applied force be clamping a couple of pipe clamps on and letting them hand out int he breeze and the wood just bent around without any effort on my part. When the towels cooled, I took them off 1 at a time and reheated them and rewrapped. In no time, O.K., around 15 minutes or so, the wood would twist into the position you wanted and then a little past. That allowed for springback and the joints were all lined up for glueing and clamping.

On your split piece, try to sand or scrape off all the epoxy glue and cleam the joint parts. Then give it another try. If you don't have any resin ( since you are doing a skin boat ) then just use yellow glue. It will hold better than the wood itself. BUT!! You will HAVE to cleam every little bit of the old epoxy off the joint or it won't stick. AND, you will be sealing the wood anyway, so the glue will be safe from getting wet. If you left the stringers a bit long, then recut the joint about a 1/16" fromt he old joint to get fresh wood. That's a must!!

Good luck with the reglue and go ahead and sister all the joints you have. Nobody will see them when the boat is done, unless the crawl inside and inspect it. ????

Rehd