I have in, for repairs, a '73 LoPrinzi dread. It's in my category of 'most neglected' guitars, for a number of reasons. One issue is an open top seam, between the bridge and end block. It's been open for a long time, and the owner mentioned she'd been 'oiling' the seam, hoping that would cause it to close. It's well oiled, the 'oil' has wicked through the open seam and inside. In my experience, glues will not adhere to contaminated wood like this. Has anyone had to deal with this issue, and had success removing or sealing off the oil, and getting glue to adhere? Also, while examining the guitar, it took me almost 45 minutes to realize it's made of flatsawn(I think) Brazilian rosewood: the back is plastered with stickers, and the finish is very heavily checkered. It's so checkered, I think the wood surface itself is heavily checkered: is this characteristic of lower grade Brazilian?
Check this out. Oxalic acid may do the trick.
Sometimes it pays to be selective about which jobs one accepts. If success is low probability better to pass on the job. If I were to tackle this, I might seriously consider removing wood along the edges of the crack and putting in a splice. But, then again, I would just pass on the job.
Thanks for your replies and suggestions. Dave, the Behlen's 714 does not come up for me on a google search- have you bought it recently, or know of a source?
Rob, your point is well taken, sometimes it's better to decline...I have considered, that it may be necessary to remove the contaminated wood, to get rid of the oil. If I take it on, it will be time and materials.
I think the options are limited. The Behlen's 714 is worth a shot but cutting out the contaminated wood and patching in new is likely the most sure fire.
To my knowledge, Oxalic Acid will only remove mineral stains.
The finish damage looks like water/ high humidity damage to me, maybe from storage in a very damp place like a basement, while in a case.
Just spitballing here, but what about some type of soap? Maybe Fuller's Earth?
There is a material called "whiting" that is sold specifically to remove oil and grease from wood. It is most often used by the gun trade because gun stocks get lots of exposure to oil and grease. The whiting itself is finely ground calcium carbonate which is basically chalk, and pretty harmless. It is, however, mixed with 1,1,1 Trichloroethane, which should probably be used outdoors, or with good ventilation. The mixture is a paste, about the consistency of "pancake batter." The Trichloroethane dissolves the oil and allows it to wick into the calcium carbonate. Once the Trichloroethane has evaporated, the procedure is repeated until the calcium carbonate shows no further staining.
My whiting came from Brownells. Inc. Montezuma, Iowa.
George, thanks, that's excellent, and I'm familiar with Brownell's.
Paul, I think there has been some water/humidity exposure, but the owner stated she bought the guitar 'new', as a second, because of the checking(i.e. it started right after finishing).