Shellac over furniture oil?

[Bryan Bear]

Okay, i'm a big dummy. I'm closing in on the final stages of building a new basement workshop. In order protect the Laminate countertop on my bench when chiseling and carving, I have two sections with luan inserts (that I can replace when they are worn). I had a bottle of Old English oil that I use on fretboards (Amy's recommendation) and I thought it would make them look nice. I didn't think it through very well. . . You guessed it, I set a back down on one of these and when I turned it over I saw the huge dark spot. It sat there for about a week; there is zero chance of sanding it out. I had planned to (my cruddy version of) French polish this guitar. When I have the guitar in the white, can I oil the whole thing and still hope to use shellac?

[Mark Swanson]

I think you'll be fine, but I don't think you would need to oil the whole thing. You may not think so but when you put on the shellac that dark spot will blend right in. The shellac should dry just fine right over it- we mix oil with shellac when we french polish anyway.
Of course, the final thing I'll say is the first thing you should do- test this on scrap. Try and duplicate your situation, same wood, same oil and everything.

[Bryan Bear]

Thanks Mark. I think you are right. I wasn't thinking about the fact that I use oil when I french polish. This was a bit of a panic post. The first thing I did when I saw the spot (actually about 15%nof the back) was to come here for advice (and the calming reassurance I have read and given here quite often). Well, really, that was the second thing I did. First I collected up'all the off-cuts and put oil of different amounts on them to test. . . I'd still appreciate other comments especially if someone has been through this.

[Clay Schaeffer]

Hi Bryan,
Old English is basically mineral oil, a non drying oil. You might be able to pull some of it out of the wood by washing it with dish detergent, then rinsing with clean water.

[Bryan Bear]

Thanks Clay, I'll add that to my scrap tests. I'm not sure how I feel about washing a thin plate like that though. I'm still operating under the assumption that it will not cause a problem with shellac (I hope). I'm letting most of my scrap pieces slowly absorb some oil for later testing (like the real plate did). I did put a coat of shellac on one piece last night and it looked great, much nicer than the part that had no oil. The down side is that I don't have a lot of hope that it will disappear under finish, but the upside is I may end up with a nicer looking color. . .

[Clay Schaeffer]

Hi Bryan,
I've used drying oils (boiled linseed oil) under lacquer to enhance the grain and color of the wood. I let it dry a couple of weeks before top coating to avoid adhesion problems. I would not be surprised if the dark spot didn't disappear under shellac.
Another test you could make would be to see if a drying oil would cover and blend in a spot of old english polish. It might enhance the color of the wood and provide a barrier for the finish.

[Tom Harper]

I am not as convinced as others that the spot will disappear under shellac. I learned to French polish without oil, and my motivation was a cedar top that shows oil splotches because the oil got into the wood unevenly. The splotches are still there after 15+ years. It was my first guitar and fortunately, the rest of it is so ugly the splotches don't stand out. It sounds bad, too. I think consistency is important in the execution of an instrument. But I digress...

Eugene Clark performs a wash coat with alcohol before starting the application of shellac. Apparently he really washes the surface with lots of alcohol until bleed out of rosewood is pretty much nil. You might try something like that to even out or remove the oil. Again, try on some of your scrap. Depending on the wood, you may not want to deal with the results of bleed out, e.g. Indian Rosewood. I have not used Eugene's method, but a friend studied French polish with him and was pretty animated when he started explaining this step to me. At any rate, it could work for your situation.

[Bryan Bear]

Thanks guys. It is clear to me that the problem will not disappear under shellac, but the shellac does seem to be drying fine over it. I haven't really built up any type of finish thickness yet though on my test piece. By the way, this is American Black Walnut. I have tried cleaning some scrap with alcohol and the early results are not promising. Each time I clean with shellac I can see a small improvement (or at least I imagine I do that is how small) but when I let it set, it looks the same as it did when I started. I suppose that could mean that with enough cleanings I could eliminate it, but I would spend more on alcohol than the guitar and my time are worth.

At this point, I think I will either end up oiling the whole guitar before french polish (not sure what pore filling method I will use) or gong with tru-oil (assuming my tests show it will cure over the stain).

[Waddy Thomson]

Just a thought Bryan, but you might want to wait a few days and see if some of that oil works it's way to the top of the shellac surface, as oil you use for French polishing does after it sits. That's particularly true of non-drying oils.

[Clay Schaeffer]

Hi Bryan,
If you do oil the whole thing, do a test to see if a drying oil will blend in the mineral oil stain. Using a drying oil will make finishing less problematic.

[Bryan Bear]

Will do Clay, this is going to my brother who likes the look of a well worn instrument showing the mojo of of all the music played on it. This is why I was going to go with french polish; I figured it was soft enough to show some wear (rather than just the scratches that will inevitably happen) but could be brought back to life easily if he ever decides to. With that in mind, Tru-oil was my second choice. Second because it is not quite as easily repaired. I am going to focus my tests on seeing if either of those finishes will cure properly over the oil already there, since I have kind of lost hope for removing it.

Waddy, I thought about the oil coming to the surface while french polishing but I'm not so sure it is the same thing for a few reasons. There really isn't that much oil used during french polish and that oil goes on at the same time as the shellac so it is not already soaked into the wood. When you spirit off (as I understand it) you are using alcohol to dissolve the oil in the shellac to allow it to evaporate away/ be wiped off. Since my cleaning with alcohol was barely -- if at all -- effective I don't see the french polish precess helping all that much. I could be wrong and your FP looks better than mine, betraying your more expensive experience. . .

[Chuck Tweedy]

Bryan, you may be able to get the oil out of the wood by washing with a solvent, however, this is not going to help the situation.
The real problem is that Old English Scratch Cover (which is what Amy has recommended) also has a dye in it. A very strong, dark brown dye.
That is never going to go away, even if the oil is gone.

[Bryan Bear]

Well Chuck, the one thing I have going for me is that this was the light wood formulation, the dye is much lighter than the walnut. What solvent do you recomend? The alcohol was not really working.

[Chuck Tweedy]

Naphtha

[Bryan Bear]

Thanks, I'll give that a go.

[Bryan Bear]

BTW Chuck, the naphtha appears to be working. Albiet, slowly. Thanks!

[Bryan Bear]

All clean, no trace of oil. This place rocks! BTW- the offending bench-top inserts have ow been covered with poly so this should not happen again.