stripping back a tru-oil finish

montyveda

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My ignorance/innocence has got the better of me...

woops.jpg

what was a lovely tru-oil finish on my cedar top now has loads of scratches; a result of me slipping over onto the top when sanding around the sides.

Sanding down through the scratches is taking me down through the finish; evident below the pickup slot and near the edge below the jack socket hole.

I presume the whole top will need taking back to something that's consistent with no patches, but having never done anything like this before, can i just refinish the patches with tru-oil?
 

old wrench

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Yes - after you sand the top back to a consistent-looking finish, you can re-apply TruOil :)

But, if you are wondering if you can just apply TO to the patches (more like a "touch-up") and get them to match the rest of the top - it's hard to say anything more definite than "maybe" without further information

If the only thing you've done to the top was just applying TO (with no stain or dye or other coloring), I would certainly give it a shot and apply some TO to one of the patches and see how it matches up - you don't have anything to lose, and it may very well blend right in

I've done some touch-ups on TO finished necks and the TO touch-ups blended in very nicely with the rest of the finish - at least good enough to satisfy me, and I'm a picky s.o.b.

.
 

Boreas

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My ignorance/innocence has got the better of me...

View attachment 1001215

what was a lovely tru-oil finish on my cedar top now has loads of scratches; a result of me slipping over onto the top when sanding around the sides.

Sanding down through the scratches is taking me down through the finish; evident below the pickup slot and near the edge below the jack socket hole.

I presume the whole top will need taking back to something that's consistent with no patches, but having never done anything like this before, can i just refinish the patches with tru-oil?
I am not exactly sure how you wore off patches on the top by sanding the sides, but I personally would take the easy path - try touching up the spots with TO. As long as the top was not stained prior to finishing with TO, I would expect the spots to blend in pretty well with an equal number of coats. It may not be perfect, but worth a try. Keep in mind some of the lesions will end up under the pickguard! If it is unacceptable after trying to blend everything in, then you'll need to strip it.
 

montyveda

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Thanks guys.

I'm not planning on putting a pickguard on it so the only place i can hide anything is under the saddle.

By the time I'd worked my way round and sanded out all the scratched areas, I figured it'd be easier to sand back the entire top instead of patch and match numerous small areas. It feels like one step forward two steps back but hey-ho.
 

Boreas

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Thanks guys.

I'm not planning on putting a pickguard on it so the only place i can hide anything is under the saddle.

By the time I'd worked my way round and sanded out all the scratched areas, I figured it'd be easier to sand back the entire top instead of patch and match numerous small areas. It feels like one step forward two steps back but hey-ho.
Enjoy the journey.
 

montyveda

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TBH I'm not really enjoying this... I've spent the day sanding it back and whilst still patchy, it's not far off...

sanding back.jpg


I had a search on other threads and some recommended using acetone to remove tru-oil. I tried using some 99% acetone nail varnish remover on an offcut but it didn't seem to do much, hence going the slow hand sanding route.
 

Freeman Keller

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The first guitar that I finished with TruOil was a big disappointment. I was able to remove it with commercial paint stripper and finish in lacquer. I believe the paint stripper contains methylene chloride which is now banned in some states. Chemical stripper may damage your binding.

I haven't done TruOil since.
 

NoTeleBob

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Unlike other finishes that sit on the wood, and oil finish tends to be absorbed into the wood. So there's a fair amount of sanding to actually remove some of the wood. Or, as Freeman said, a stripper that will let it be pulled out with steel wool or rags or whatever.

In some applications, this is a real feature. But when it's time for removal, I think you need to get into some moderately aggressive techniques. Or, less aggressive, and lots of time.

If you keep at it, eventually you'll be back to bare wood and can redo it evenly.
 

montyveda

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The first guitar that I finished with TruOil was a big disappointment. I was able to remove it with commercial paint stripper and finish in lacquer. I believe the paint stripper contains methylene chloride which is now banned in some states. Chemical stripper may damage your binding.

I haven't done TruOil since.
Paint strippers in the UK aren't what they used to be since certain chemicals were banned.

There's no binding on this build since I'm not really a fan of it.

I was happy with the initial truoil finish but now i'm having 2nd thoughts and am considering clear briwax. I've used that a lot on furniture in the past and I like its finish. Not sure if it's suitable for a guitar though.
 

Beebe

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Violins makers will seal the wood with a "ground" before applying varnish. Their goal is to prevent oil varnish from soaking into the thin wood and dampening the liveliness.

Old school furniture finishers will typically apply thin shellac after sanding. Their goal is to prevent blotchiness due to uneven absorption of stain or varnish. For transparent finishes the shellac also lends a natural amber and highlights the grain differently then the subsequent coats resulting in a finish with more depth and beauty.

I think TruOil is designed to penetrate and seal the wood without adding thickness and to preserve the natural feel of the wood with a minimal number of coats. Gun people do not like to affect the dimensions of the firearm with coatings. This is why the metal is blackened chemically. A surface coating would throw off the tolerances. I would hypothesize that they take a similar approach with wooden parts as well.

TruOil is basically an oil varnish thinned with solvent and oil, and maybe with some wax added.

I think my approach would be to treat the TruOil like a violin varnish and seal the wood first.

Even after sanding some TruOil may remain acting as kind of a sealer for additional TruOil. But sealing the wood after sanding with shellac might be a good idea. It might at least make the TruOil easier to remove without removing wood next time if necessary.

I would be curious to see if the TruOil would adhere without being directly against the wood. My guess would be yes.

As with every finishing scheme, testing first would be advisable.

Also a good lesson on sanding out scratches. Simply can't be done while maintaining a flat surface unless you sand the entire surface to below the deepest scratch.
 




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