Shellac vs. lacquer

[Bill Ballard]

At 11:37 PM -0700 7/17/02, Susan Kline wrote:
>It sounds like you've been having a very positive experience with 
>your shellac hammer-building. I >sincerely hope it continues well 
>over time.

Right now it looks very promising. Last year when the board was just 
fresh, I was worried that I might have gotten an "dim-bulb" board. 
Apparently, the strings just wanted to be hit by a harder hammer. 
It's what i was hoping for in this piano. The 6th and 7th octaves 
just sparkle. The bass can easily go up a notch in forcefulness, if 
needed. For tonight's concert, I sat at the back of the 400-seat 
closed concert shed, and even with the piano pushed back in from the 
proscenium, and at half stick for this Dvorak piano quintet, even at 
this suppressed volume, the sounds were very clear. Sustained and 
projected.

>Can you describe the solution you used? What dilution, which
>alcohol? Or premixed? Did you find that the color was a problem? 
>What impressions did you have as you >applied it? Did you do any 
>wet-voicing with it?

3# clear shellac from the local hardware store (date of manuf: 
10/4/01) which I cut back to 1#, for caution's sake using the 
instructions on the can. Denatured alcohol the next shelf down from 
the shellac. Methyl, Ethyl, I can tell'em apart, they've got the same 
freckles and buckteeth. Color was not a problem. (BTW, that's one of 
the reasons I went down to 1#: nice white Steinway hammerfelt should 
have big butterscotch stains on it.)

As for the shellac's ability to penetrate the felt mass, as mixed, 
it had (SWAG) 25% of the viscosity of plastic/acetone, but it flowed 
right into the shoulders even with a pre-existing plastic content. 
Wet-voicing? Do I eat my brownies after only 11 minutes of baking 
time? Does the bear sit down in the woods? No, I regulated or tuned. 
(I especially wouldn't want to hit a wound string with a hammer still 
wet with shellac.)

>It would be interesting, another time, to compare how long the 
>shellac takes to set up as opposed to the >lacquer or 
>acetone/keytop. Especially since keytop's main virtue appears to be 
>its fast drying time.

I did put a drop of plastic/acetone and the 1# shellac on a piece of 
mirror. The plastic was solid nearly instantaneously, the shellac was 
still gummy after a minute. But if we're going to experiment, let's 
be rigorous about it. First, observe and time the evaporation of the 
solvents, equal volumes of each. Then, before observing the hardening 
of the resins, make sure that you samples have the same % of solids. 
One might assume that viscosity and solid content might be directly 
related. Maybe not though, in which case rigorousness of the 
experiment just got more complicated.

Actually we're now getting reports of working times for lacquer which 
would dry-time a moot point.

At 11:03 AM -0700 7/18/02, Susan Kline wrote:
>At 08:19 AM 7/18/2002 -0700, you wrote:
>>Susan:
>>
>>If you are comparing dry time for your own style of application (a 
>>few drops on the crown), I haven't >>found that dry times vary that 
>>much.  Lacquer/acetone will dry in 15 minutes.  Plastic/acetone
>>maybe a little faster.  It's only when you soak the hammer that the 
>>dry time increases.  With lacquer I >>find that in 2 hours you have 
>>80-90% of what you are going to get.
>>
>>David Love
>
>Certainly the short drying times (for small amounts) has been my 
>experience as well. For crown voicing, which only uses a few drops, 
>I don't feel that cure time is really an issue. Fresh shellac made 
>up with alcohol nearly free of water dries very fast, anyway.
>
>Susan

And from where I see, we're back to the point of cure time, which was 
my initial question. There is something going on here, as I 
discovered this noon, arriving partway through the last rehearsal. 
Arriving for the second visit a week after the first, the condition 
of the hammers was as I remembered and anticipated them. Arriving for 
the third visit, the actual concert tuning, I found then entire 5th 
octave hissing at me (the pianist as well), with a handful of hissers 
in the neighboring 4th and 6th octaves. So I dealt with it, in a 
three-hour session also including the tuning. After the concert, I 
was happy, so was the recording engineer, and I got a hero's welcome 
by the musicians in the corridor downstairs.

So why did the 5th octave turn nasty on me? Cure time? I doubt it. 
The resin at seven days was  predictable. Another three days later, 
and the 5th octave had gone skinhead on me? The curing should follow 
a smooth taper by which I could predict the sound at the third 
session, compared to the sound at the second. Work-hardening? The 
musicians only have access to the piano during the hours specified in 
the contract. The hammers had no play in between any of the three 
sessions. At this point what we have left is Karma.

I think I've can come up with a means of making resin samples for 
observing elasticity. Somewhere around the house I have a draftsman's 
eraser template. 0.01" stainless steel, with narrow slots cut into 
it, so you can do surgical work with an eraser.......

Damn, 12:50AM and I've got another day of rehearsal pianos, a 
harpsicord and capped off with a concert tomorrow night

Bill Ballard RPT
NH Chapter, P.T.G.

"May you work on interesting pianos."
     ...........Ancient Chinese Proverb
+++++++++++++++++++++