Rich - I'm not positive about this, but I suspect it's for the love of movers. I'm not thinking like a wood worker, but as a furniture mover. I actually spent about 10 years as a mover and know if a finish were to be applied to the back of an upright piano, it would be more difficult to move. Most of the weight of a piano is in the back. We would wrap our hands and arms around the front and lift from the back where the handles are located. Just a thought from a way former furniture mover!

 

Rich
The sound of a piano is subtle, but I doubt (no expertise) that the finish on the back or elsewhere, would have any effect. The acoutisics are produced by the strings and the sound board, and then exit the piano in a controlled fashion. I think the back finish has no influence. I think I would bet on it. A piano is not as subtle as a violin.

Hope you had a good July 4th. I finished a project, relaxed, just got in from the porch with Kermit, my bird, enjoying the outdoors. Sherie is making pizza, normally a Tuesday night thing, but she is busy tomorrow night.

Pretty quiet today, just back from La Connor, Washington on vacation for a week.

I think the lack of finish is economics…...........(-:

 

Oh, have some experience with pianos, not much playing, but we restored a square grand piano, and gave it to a local long term nursing facility when it didin't fit the decor anymore. My mother was fairly accomplished, and I have owned a few pianos, mostly for the children. Didn't want you to think I was coming from left field…...I always come from right field….(-:

 

Re Bernies remarks….....I remember the handles as well…......

 

I think the answer may be as simple as most upright pianos were (designed to be?) up against a wall and, thus, there was no need to finish the back. I'm guessing.

Of course, it could be just the other way around too. They were pushed up against the wall because of their unfinished backs.

 

I like pierce's answer best though the others are good too… but pierce's profile pick wins out!

 

These 2 links should clear up any questions abut varnishing a piano soundboard.

http://www.musicrolls.com/cb/soundboards.html

http://www.countrypiano.com/restoration/soundboards.htm

 

If you think about it, the back of a piano is something like an open wall. putting finish on what's exposed wouldn't affect the sound, but it still wouldn't look very good either.

If you are positioning an upright piano where the back will be visible and you want it to look nicer, I would recommend adding a finished panel to the back. Since the piano is already designed to be pushed against the wall anyway, I don't see where this would have a negative effect on the sound.

I'll add that I've never tried this, but I do speak from having owned and played pianos for close to 40 years.

 

Luthiers get really picky about the wood used for their guitars, especially things like Sitka and Englemann spruce for the soundboard. It doesn't stop them from grain filling and applying a hard film finish.

For an upright piano, it wouldn't matter, IMHO.

 

Is the piano against the wall?

 

Thanks for the input.

The piano in question is at our church and with the new configuration of the sanctuary, its back is now exposed to the congregation. There has been talk of a cloth on the back side but the musicians are very resistant to that idea because of the potential impact on the sound.

The front, top and sides is walnut with a beautiful finish. The back is unfinished and it looks like it might be maple. It is a very light colored wood. The back of the piano is distracting. I'm considering applying a dark stain. Of course, this is, essentially, an irreversible thing to do and I want to research this as much as possible before taking the step. I'm probably going to visit a piano store today to get their advice.

 

Rich:

A thin cloth would work fine…that wouldn't affect tone as much as it would loudness. Much of the sound of the piano comes out the front from under the keys or out of the top. In fact, many churches will mic the piano at those spots. You didn't say if it was miked, but that would largely make the issue a moot point.

 

I don't think thin cloth will affect the sound significantly, and it would probably be the easiest solution. Since it is easily reversible, why not try it?

If not, applying a dark stain certainly won't hurt.

 

Thanks again -

All I can say about the thin cloth idea is, whether rational or not, the church musicians object to it.

However, you are right, it is easily reversible and should be tried.

 

Alot of good posts on here about this. I started refinishing furniture for my own use many years ago, when this older lady that was a buyer-refinisher-seller took me under her wing. I was lucky enough a short time after that to hook up with a local piano refinisher, he did it from start to finish, anyway it is an out of sight out of mind thing. Most had no finisih on the back although some actually came with a very minimal amount of clear finish on the back, it has no bearing on the sound quality. I went on to finish several pianos for Dolywood in Tennessee and the gentleman that ran the Piano store there insisted i put a clear finish on the backs. As to the thin cloth i have seen several pianos in his shop as well as churches that had a cloth on the back and many times the cloth mtched the decor of the church. JMO though.

 

To each his own..
Our community actualy has a baby grand painted with "roxitone" the speckled paint like you used to see
in car trunks, or boots as some call them..
Frankly it looks like hell, mostly grey with red speckles, but no musician's complained about the sound..go figure..
And it'd probably take a MAJOR fundraiser to"restore" it..

 

In all my years of piano restoration no finish was added to the back of the sound board unless it was specifically called for by the owner. Even then, the owner was asked to sign a release absolving the company from any real or perceived loss of tone quality. In a sound board that large either no finish or a finish on both sides will balance ambient moisture loss or gain which will effect dimensional changes.
There was an electric "heater bar" called a DAMP CHASER that was used in environments with high humidity that would help diminish moisture related changes.
Just my experience.
Bill

 

One thing that might help with concerns about cloth would be to suggest the cloth used to cover speakers. The material is designed to be "acoustically transparent".

At least that is what I was told when I built a set of speakers. It makes sense as speakers sound about the same with and without the covers.

A search on google for "speaker cloth fabric" shows several options.