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I'm making solid-body electrics with a polyurithane finish that will have to be wet sanded and buffed.

7 years ago I worked for a short time at Lado Guitars in Lindsay and sanded a few guitars there. They used a light oil-bassed material as a lubricant instead of water, but I don't know what it was. It was a little like Kerosene, but lighter and less smelly.

Any suggestions?

Distilled water and a drop or two of dish soap. Change and clean bowl thoroughly in between each paper grit change...

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

Mineral spirits works as well, if you're worried about swelling.

I use the water and dish-soap method myself, just...very sparingly. You do NOT want water getting into any drilled holes.

I use a little Murphys oil soap in water.

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Anderson Guitars
Clearwater,Fl. 33755

Understanding the purpose helps you make these decisions much easier.
The liquid is used to carry away sanded debris and extend the life of the
paper by keeping it from clogging. It's not there so much as a lubricant.
Oil, water, mineral spirits, they all would do essentially the same thing.
They each have their +'s and -'s.

Water is cheap and available, but it swells wood and crack's the finish if it
gets in to a screw hole or unfinished edge. Soap is often added to brake
the surface tension of the water, so that it flows out on the finish and
paper rather than forming little balls that roll off. This is all I've ever used,
as I've seen no reason to move elsewhere. You just have to be careful
around areas of bare wood. I had one or two cracking incidents in my first
few guitars, and none in the few hundred since.

Mineral spirits, naptha, kerosene, etc., won't swell wood, but they stink,
they're messy, and and are extremely flammable. I certainly wouldn't be
using these with an electric random orbital sander, unless it was an air
one. Of course electric random orbitals don't care for water much either,
but they won't cause an explosion. Most of these are relatively slow
evaporating, but may also evaporate too quickly, defeating the purpose
by leaving the debris behind that they were supposed to carry away.

You can use non-water, non-flammable things like mineral oil, or any
number of other oils. These won't swell wood, won't explode, and won't
prematurely evaporate. They may stain the wood if they get in, and can
be a real nuisance to clean up. If it weren't for the whole wood thing, a
machine cutting oil would probably be perfect.

Being a water-user with limited experience to the others, I may be
missing some things here and only giving one side. So if there are any
other spirit or oil users out here, please speak up.

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Eschew obfuscation, espouse elucidation.

    Machine cutting oils are essentially water and oil combined with a detergent so they mix. There's no reason why mineral oil and dishwashing detergent together couldn't be used as a substitute.

    I've used just water, very sparingly, to avoid contact with unfinished sections. It doesn't require much.

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)