I had a slight set-back in my build Sunday. I had glued up some 1/8" ash to 1/2" Canary Wood for neck material late in the week. The glue up gave me a "board" that was @ 5/8" x 4" x 42" before ripping and jointing to size. I was hoping to get two neck/head blanks out of this then add a 1/4" fretboard.
I went with the Canary Wood because it a Rift cut piece, looked cool and the price wasn't crazy. I thought it would add a little somethin, somethin to the guitar. The Ash was just to get to the thickness I wanted. Ash is just, well, Ash.
A friend of mine has a pretty nice shop so I ran it over there to rip and size the necks. My jaw just about hit the ground when watched this glue-up literally bowing and crowning as it passed through the saw blade. Never seen anything like that. It's not that thick at 5/8", but I would think that the lamination would have made it more stable and not less. The two pieces of lumber were fine but it's almost as if the glue-up freaked out the two ;)
Looks like I'm starting over. This time, I'm think going with 3/4" for my glue up and making the whole neck and angled head out of that one piece.
If any of you woodworking guys have some thoughts as to why this happened, I be happy to hear them. I don't want to make the same error again.
RC
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Not sure what you've glued-up, but is doesn't sound like any laminated neck I've ever come across. Typical is a centre strip say 1/4" wide and two pieces of contrasting wood glued both sides of the centre piece. You can just take take one board, rip it down the centre, plane it , reverse the pieces and glue together without a centrestripe for a non-contrast neck. It sounds like what you've done is just glued one piece of thin wood on top of another (like you'd glue a fretboard onto a neck) - that's not how you laminate a neck.
It's likely that the timber wasn't properly seasoned - it's quite common for a piece of timber to warp as it's ripped, as the stresses are unlocked by the sawing. In which case, you need to stack it, leave it to season, plane it all true and square and try laminating it..you might get away with it..but otherwise, it's firewood
"...that's not how you laminate a neck."
Normally I would agree with you, John. I'm a far cry from being a Luthier but know a little about lumber. Considering the stresses involved, laminating as you say is the proper approach. The variable here (at least in my original thinking) was that I was going to be using a Aluminum fret board I'm finishing that's from 1/4" bar stock. That being the case, I figured that once everything was glued up along with the fret board, it would be hard pressed to do much of anything but to lie true.
I was hoping to be able to get two partial neck blanks out of this by gluing up this way. Both were going have a 1/4" fret board applied afterward so all I figured needed was 1/2" to 5/8" and had 1/2" with the Canary Wood. The addition of the 1/8" Ash was an effort to add stability (ironically enough) and get it to time out to the top of my box. The fret board was going to be installed and it would run onto the top some.
I was anticipating some bowing but thought I could use that to my advantage. The crowning, not so much ;) Live and learn I guess.
I know it's after the event, but you'd have been better ripping the board into 4, reversing the grain and laminating them that way to give you 1 inch thick(less the saw cut) blanks. Laminations in a neck need to be balanced around the neutral axis of the neck..ie down the centreline, putting in laminations to build up the thickness is asking for trouble - it's quite common for necks to acquire a bow one way or the other after the fretboard has been glued on. I wouldn't rely on the aluminum to be the magic bullet for stiffness either..it will help a little, but as it's only on one side of the neck it will be mainly in compression rather than really contributing to stiffness like the web in an "I" beam....plus you might get thermal expansion problems causing the neck to bend in a way you don't want it to. Sometimes you can't beat a simple 1" thick piece of decent oak.....
Trouble is what got, that's for sure ;)
I spoke with a custom cabinetmaker friend of mine yesterday and he said that he can hook me up with some 5 or 6/4" H&M quarter sawn White Oak or Maple. I was hoping to use something that would be easier to shape than oak but I may just go that route.
Oak is hard, but I've made a couple of hundred guitars with oak necks using just hand-tools. Maple is nicer to work as it's finer grained, works easier and finishes easier too.
Generally lamination layers are done in 3's (or odd numbers). What you do to the front you always do to the back. What you created was a lamination with very different properties on each side. I wouldn't think an 1/8" of ash would make that much difference either. One other suggestion is that sometimes there can be stress inside the wood that is relieved when cut, maybe the combination of factors all weighed in.
Just looking at diagrams, the rift sawn probably has very little resistance to crowing and the flat sawn, depending on where the slice is taken would have a higher tendency to crown. My amateur eye would also suggest this isn't the most stable laminate configuration. But I humbly reserve the right to be wrong. :)
My guess would also be that unless the wood was soaking with acetone, it probably didn't affect the glue joint. Titebond recommends wiping oily woods with acetone prior to glue-up.
From the description you have given, I think the bond strength is just fine as it is deforming both pieces of wood.
Exactly, Rift or Quartered is the most resistant to movement. The flat sliced isn't but I didn't think that a 1/8" of flat sliced, particularly when it's used in a glue-up with a 1/2" rift cut board would create a problem like that. Apparently I was wrong.
On the bright side, I think I have a good start material wise if I ever want to make a barrel ;)
RC
Drum stave. :)
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