New Boom

[BillyBudd]

Some opinions please on a boom for the Bolger Chebacco (20' cat-yawl). 14' x 2.5" boom. Recently (this evening), I discovered a nice spruce, 16' with a 6" butt, straight, and it seems, knotless. It was cut sometime in Jan. or Feb. and has been lurking in my wood pile. Thought originally was to take it down to the required dimension for a solid boom (gaff rig would like the weight vs. a hollow boom), but a good suggestion was to cut the spruce down the middle, reverse 1 side end for end one piece and glue up to control for warp. Might it also go inside (center) to out as well? Thoughts?

[Bayboat]

My vote is for ripping the piece down the middle, end-for-ending one stave, and gluing on a nice straight base. Stretch a string to gauge straightness. Don't start to dimension it until it's glued up. Lots of clamps. That will give somewhat better control over warp than just flipping the kerf to the outside. My preference is for Weldwood plasic resin glue, but epoxy is OK if a good finish (varnish or paint) is maintained.

Unless you're really pressed for time, after ripping the piece you might let it dry out a bit more; perhaps bring it inside.

[ 04-02-2005, 02:03 AM: Message edited by: Bayboat ]

[Paul Scheuer]

I think that the lathe people use something called a turning round that is essentially a re-assembled log. They do it with four pieces. It results in no pith, and less warping. It's probably a stronger piece too.

I also seem to recall an article in an early WB that mentioned the same.

[Bob Smalser]

That stick is still at least 30% moisture content (low end estimate - 50 or 80% in individual logs isn't uncommon)....gluing it up immediately might not be a good idea....and if you rip it through the pith and dry the faying surfaces it'll likely warp.

I think you'll have to either make a boxed-heart cant and season it before glueup, or shape it and use it green. A 6" diameter tree is generally too small to mill out the pith, which often corkscrews a bit higher in the stick.

Removing an equal amount of wood from all sides of the pith will generally prevent moisture gradients and warping.

That said, I find poly glue does a pretty good job with "green" wood....but not quite that green - my failures being in exceptionally wet cedar....if your stick is 35% or lower in the center, you might give it a try. You can always make another boom.

[ 04-02-2005, 09:06 AM: Message edited by: Bob Smalser ]

[BillyBudd]

If I read these replies correctly, there might be two options: 1) the easiest is to bring the log down to size, 2) cut it in two (or even four) parts and let them dry out (probably would need to secure them to a table to try to control warping) then epoxy back together or invert putting pith area outside for trimming. What do you all think about 1) bringing the log to shape after a few more months of air drying and when to shape put it on a table with some wedges securing it in place? Or back to 2? :confused:

[Bob Smalser]

I'd shape it to size and use it.

6" at the butt is too small for anything else.

[BillyBudd]

Think that's what I'll try. Thanks for comments. Just sent you a digital photo of butt end. Thought that there's lots of annular rings here for a 6" butt.

[Bob Smalser]

That's a real nice, tight stick. If the pith is as straight as it is centered, you'll have no problems.

I suspect it is, because that tree grew on flat ground and got uniform sunlight for it to be so nicely proportioned.