Friday, August 5, 2011

Grand Piano Restoration: Finish Removal

One can purchase the consumer products from the hardware store to complete small refinishing jobs. However, because of safety regulations, these products have a low concentration of active ingredient to remove the old finish; using them is time- consuming with variable results.

Stripping woodwork of the old furniture finish is to be done quickly. When refinishing a piano, there is more than 40 square feet of material that has to be refinished; some of the boards have both sides with finish on them. It is best then, to purchase the finish remover with the highest concentration of Dichloromethane. This product will move into the outer coats of finish and rip them up quickly.

Use a stripping agent that is a gelled stripper instead of a liquid. Also make sure that the stripper used is water soluble. This allows one to wash the boards down with water to neutralize and remove the stripper along with any excess of old finish. The water will also open up the grain and coarse steel wool or those green scrubby pads can be used to remove the tough bits.

In addition, for safety concerns, is the fact that one has a hose nearby in case of accidental contamination to the eyes, hands, or other areas of the body, or an accidental spill of the chemicals.

Remember to stay away from the chemicals while they work. Dichloromethane is a known carcinogen so one does not want to stand around breathing the fumes continuously.  Wipe the stripper on with a brush and leave the boards for a minimum 10 minutes, then using the hose, wash the stripper off. I use the end of my shop driveway for washing the board down as the hard surface allows the water to wash away and leaves the old finish that I can scoop up and place in the garbage.

I do the majority of my stripping outside, so there is plenty of fresh air available. Use a breathing mask, gloves, and eye protection for this task.

Here are some photos of the boards with the finish removed, some of the previous damage found underneath, and samples of the different woods used to make the cabinet in a piano. 
The different woods used have varying base colours and grains; this is why one must learn the art of colour tinting in order to make all of the wood the same colour. Please begin at photo # 84 in the link provided below.

Same photo set starting at photo 84.

Finish Removal

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