I'm working on the mast for my Skerry (what was your boat?) , and it make me wonder:  The scarf is about 4 feet from one end, and 8 feet from the other.  Shoud the scarf be closer to the top or the bottom of the mast?

Doug

Well that is really quite interesting! Sorry for your trouble though.
Epoxy should be much stronger than wood. And, laments should be stronger than one solid piece, particularly if you attend to grain orientation. Did the break have fibers of wood imbedded in epoxy or did the break occur in the epoxy joint itself? If the epoxy failed it would seem to indicate a mix or application problem. What was your thickening agent? Epoxy has virtually nil tension strength without a thickening agent of some kind.
When bonding critical wood components like lamanates and and scarfs I try to saturate the wood with un-thickened epoxy then do the actual glue up with celo-fill as thickening agent. I put my scarfs higher on the mast but each of three laminates were scaffed in different locations, about two feet apart.
Once, I was quite alarmed at watching the degree of flex when some one else was handling the boat, seriously, you could have shot an arrow from that bow, but nothing came undone. My spars are Eastern White Pine.
Very interested in what John might have to say about this. I’m particularly curious about grain orientation relative to the keel line/wind force relationship.

Cheers,

ev

 At the scarf huh? This was a solid section with a single scarf?

There's always carbon fiber... or glue up a couple of pieces of 2x6 Sitka & then hack off what doesn't belong.

http://www.boulterplywood.com/

- might be within driving distance of where you are but at $10/bd. ft., carbon fiber might be cheaper.

   Based on what was said so far, I'm guessing Silver Salt is right on the money; resin starved joint. Use thinned epoxy on the end grain of both pieces for a few coats before applying thickened. For really critical scarfs, you can preheat the wood with a heat gun so that it is then cooling down as you apply unthickened epoxy, which then facilitates the end grain taking more of it up.

   Can't speak to the epoxying process, my perfectionist wifey assembled it under the tutelage of John at JLZ Canoes, but I suppose the clean break tells the true story. I like the idea of a nice one piece spruce spar, but carbon fiber might be an option. Ill check the lead, thanks.