Wednesday, April 1, 2015

applying oil finish

 A reader had trouble applying finish to boxes: "
I can do the woodwork ok. It seems good to me. Finish.  I have just sanded off the second finish because I had finger prints, and runs over the top. The top looks good, but sides are bad.
I put 3 coats of tung oil, but left finger prints on sides.
Tried spray shellac and got runs.
I just put on 1 coat of tung off and then if all looks OK I plan just to wax.
Wax is a good idea and provides a way to buff out the finish if it has an uneven sheen. But one of the biggest problems woodworkers have with oil finishes has to do with what you do to it after the finish is first applied.  I don’t know what technique the reader used to apply his finish. Tung oil needs to be carefully rubbed out at the right time with a cloth… before it gets sticky. The same applies to other oil finishes. The worst mistake you can make is to brush it on and then leave it alone like you would a polyurethane finish. If there are fingerprints, then the finish had not been rubbed out properly at the right time.

Shellac takes a completely different approach, but it is at least soluble with alcohol. Even after it is applied and hardened you can take alcohol on a rag and rub it out. You can sand down your runs and then use an alcohol rag to rub over it and restore the finish, by blending in.

One of the obvious questions that I must ask, and that has been asked me when I’ve had trouble with a finish has to do with reading the instructions on the can. They can be helpful, and are often overlooked to the detriment of the finished piece.

Make, fix and create...