A Satin Oil Finish on a Wood Instrument

Finishers discuss a customer request for an unusual finish on a musical instrument. October 26, 2007

I produce musical instruments and am very familiar with high build, high gloss finishes using polyester and acrylic urethane. However, a customer now wants a "satin oil" finish with darker shading around the edges.

I am thinking of a hand applied oil based polyurethane type finish. Is this even possible? I did a sample by spraying the shading first, which went well (I used an oil-based ILVA ebony stain), but when I went over it with the polyurethane oil on a rag, the stain smeared.

I'm at a loss on how to do this. Am I only left with spraying a hard satin urethane finish so the shading doesn't smear? I am concerned with the final finish being smooth enough if I spray a hard satin urethane. Gloss urethane gets lots of sanding before it's buffed, so I know it will be smooth. I won't be able to sand a satin finish if there are any nibs in the finish. I need ideas for the simplest, most efficient way to get a shaded satin finish.

Forum Responses
(Finishing Forum)
From contributor M:
You need to seal in the stain so it doesn't move. Add a little poly into your stain, which will act as the binder to seal in the shading stain. Then allow to dry. You then can apply your wipe-on poly without it affecting the reactive poly you added into the shading stain.

From contributor C:
The problem is that the solvent in the stain and poly are the same. Contributor M's suggestion would work, or you could stain as you did before and then seal it with shellac, and then topcoat.

From contributor M:

If you go with contributor C's way, be sure that you use only de-waxed shellac to seal in the stain.

From contributor P:
If you want to entertain the customer's request/specification for the finish, then you should get more detailed information on what they want. A "satin oil" finish is highly vague.

Find out the exact look desired and the level of durability required. An oil finish (e.g., linseed or tung oil) is an "in the wood" look that offers very little protection. A film forming finish (e.g., oil-base varnish/poly) can be applied in a satin sheen and with a few coats that are sanded smooth between each, will produce a much more durable finish.

If a film forming finish in a satin sheen is fine, then you can just use conversion varnish (CV) or 2-component polyurethane (2K PU). Who's going to know the difference?

Also, instead of using an oil-based pigment satin for the shading, you can use a dye and avoid the solvent compatibility problems.

If the customer actually wants a hand rubbed oil finish for some odd reason, start with a dye and then go with the oil.

From contributor M:
They already sell satin oil finishes. They are ready for use, and will produce a satin-looking finish. They are easy finishes to do, so why complicate the job?

From the original questioner:
Thanks for all the responses. I think I should do a couple more samples. I think I'll try the dye idea, using an alcohol soluble dye like TransTint so I can spray it and it will dry fast. I just hope the black TransTint dye will be black enough. I usually think it looks a little on the grayish side, not true black. If I remember correctly, it also has a strange undertone color - either a hint of purple or red - I can't remember now.

Anyone else have a suggestion on a good sprayable black/ebony dye? (I also tried India ink, but because it is water-soluble, I was having trouble getting a dark enough shading without getting runs on vertical surfaces.)

From contributor M:
You could add a little universal color to their dye. Mixol has pigmented colorants that would also work with the dyes.