Hi,

I had a thread here a few weeks ago and got (as usual) a variety of thoughtful advice. My beautiful Warmoth neck lost all of its relief and was heading towards backbow. :eek: Now that the ambient air in my house (winter in Vt.) is really dry, the relief is back. :smug:
I suspect differential expansion of the woods caused by the unequal absorption of moisture by the wenge neck and bloodwood fretboard. :hiding: No one else bought that. But, all the same, I'd like to treat the FB with an oil treatment. I've heard stuff about tung oil, mineral oil, linseed... etc.
I'd like to have as little residue as possible to foul up my strings, and keep the color of the bloodwood as original as possible.
Any suggestions?

Thanks,
Bill

The change in relief would have been caused by uneven expansion or contraction , as you noted. I'm glad it all evened up for you - that suggests that it may have been caused by gain or loss of moisture by the two woods at uneven rates, rather than a different "end point" of dimensional change for the two woods. That's a good thing, since if you could get the two woods to gain/loose at the same rate, you would in theory never have to touch your truss rod with the change of seasons. So it makes sense to try to slow down the wood which gained/lost moisture faster.

The thing is, I'm thinking that it was actually a case of the wenge neck shaft losing moisture faster, causing it to contract faster than the bloodwood, arcing the neck backward. If this is correct, then putting a finish on the fretboard but not the neck shaft will make matters worse the next time there is a humidity shift.

I wonder if any of the luthiers can attest to any experience in this area, to support or correct this idea.


As far as the use of oil, here are a few points that you might be missing, based on the way you grouped together various "oils."

Things like mineral oil and "lemon oil" are liquid oils that stay that way. If you leave too much on the surface, it could gum up your strings, as you note. And, maybe soaked-in oil might resurface (I'm not sure about that).

Things like tung oil, danish oil, and (at least some) linseed oil are finishes that harden into a solid, so, no worries about your strings. But since they are finishes, they require more care and effort than simply wiping on some mineral oil to moisten the wood, and wiping the excess off.

Lemon Oil would be choice #1 for conditioning and cleaning
Howard Feed N Wax #2 as above

Initially when building a bass I do usually give them a treatment of Danish Oil much like the bass bodies. Then after the first change of strings I use Lemon Oil or Howard's.

That's my process and I'm sticking with it.
Dirk

Hey, Pilotjones,

Thanks for the well-considered reply.
Something to reflect on in view of your posting:

"The thing is, I'm thinking that it was actually a case of the wenge neck shaft losing moisture faster, causing it to contract faster than the bloodwood, arcing the neck backward."

Damp conditions killed the relief; crackling dry air set it all right again. This suggests to me that the thick slab of bloodwood FB is responding more readily to the changes than the wenge is.

I am loath to put a hard finish on either surface, because the lack of finish makes this such a fast and playable neck. but I'd sooner put a hard finish on the FB than on the neck. I mean, that's what drew me to the wenge in the first place.

I'm hoping :eyebrow: that oil will prevent the FB from reabsorbing moisture. Yeah, right!

Well, thanks again, and stay tuned.

Bill

(PS - if I had to do it over again, I think I'd have compromised on the looks and just gone with pau ferro. It is very happy with the wenge on my FL neck.)

OK, I guess I got the circumstances a little backwards. Either way, good luck with it.
:)

My resource material does not include a co-efficient of expansion for bloodwood, so I cannot compare it to wenge. But your description suggests that you are right - it's the bloodwood that is reacting more to humidity changes than the wenge.

If you use something like an oil on the fboard, you will find that it SLOWS the process of dimensional change, but does not prevent it. A finish like lacquer will do more to inhibit moisture loss/gain. But then, you may not want a serious inhibitor at this point.

You must assume that the wenge is reacting to moisture change, but at a lesser rate than the bloodwood. So retarding the moisture variation in the bloodwood is probably the best bet - i.e. an oil treatment. If that proves to be less than adequate you could step up to a more impervious finish after a few seasons of trial.

I've heard stuff about tung oil, mineral oil, linseed... etc.
I'd like to have as little residue as possible to foul up my strings, and keep the color of the bloodwood as original as possible.
Any suggestions?

Thanks,
Bill

From my research prior to de-fretting my bass recently, one would consider using Tung or Danish oil if they wanted a finish with some gloss on the board. In my case, I wanted to maintain the natural rosewood color. I chose Pure lemon oil and gave it a few coats. My fretboard looks totally natural, no change in color, and there's absolutely no residue.

Because I was sanding the board, the last couple of coats were wet sanded on with very fine sandpaper. But for future maintenance, I would just apply with a soft cloth, let sit for few minutes, and wipe the excess off and buff it up.

I've read and spoken with luthiers who would encourage you NOT to put any oil on the fb at all. I think one guy said, maybe a couple of drops of lemon oil twice in the life of a guitar. I, and a couple of other guys, used to use Dr. Duck's ax wax -- which I thought was very nice (I had good luck with the oil on the strings, so any residual on the fb was just getting on the strings, which was fine). However, then I refretted my guitar -- that oil made the refretting process a major pain, and I can't say that there ever was any real benefit in the long run.

So I'm off the stuff entirely.

ltt