[CAUT] Lacquering Steinway Hammers (simpler measure?)

[Mark Cramer]

I wonder if there may be an even "simpler" way to measure and describe
lacquer/thinner ratios?

In spray-finishing we used a "viscosity cup" to govern thinning:

Fill the (calibrated) cup with thinned lacquer, then record the time
necessary to drain through the hole in the bottom of the cup.

Thinner (less solids) drains faster, and thicker (higher solids) drains
slower.

i.e. "22 seconds" in a "Zahn" viscosity cup was common for a 2:1 dilution of
spray-lacquer.

(weather change dictates the need for varying ratios to secure consistant
flow-out)

I introduced viscosity measurement to battle the "1/2 bowl of soup syndrome"
with our painters;

"To finish a panel, they would simply "thin" out the last few drops of
lacquer, rather than make a new batch, just like the cook does to the soup,
at your favourite greasy spoon!"

If you've determined a specific viscosity though, you simply time/test it
before EVERY application. The original "solids content" of Tom, Dick or
Jane's lacquer is no longer a concern.

I also agree with those who don't wish to overcomplicate, however, a "common
language" sure makes the exchange of information more useful.

My worry has always been evaporation.

I never mark my containers to know. But if it does, it's the thinner that
evaporates, and your careful scientific ratio would change, just sitting on
the shelf. (!)

(like the cook, I hate seeing a few drops go to waste, and have a nasty
habit of pouring in thinner til it just looks right)

With a visc. cup, you could take that 1/2 used bottle from 96' and simply
add thinner til it timed out right. (no math)

Now "Fred," where can I go get that beer I so richly deserve?  :>)

Mark Cramer,
Brandon University



-----Original Message-----
From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]On Behalf Of
Fred Sturm
Sent: Wednesday, November 10, 2004 7:40 PM
To: College and University Technicians
Subject: Re: [CAUT] Lacquering Steinway Hammers


--On Wednesday, November 10, 2004 10:47 AM -0500 Russell Schmidt
<hrschm2@uky.edu> wrote:

>       Now, I am now wondering how meaningful the various opinions are
> about the strength of the lacquer solution 15:1 3:1 etc. , without a
> specification of the solid content of the lacquer being used.

	Yep, you'v'e got that right. That's where the rub has been all along, and
why any number of people were disagreeing vehemently about what dilution to
use. I was skeptical as all get out when I heard the Steinway folks saying,
repeatedly, 3:1, soaked to the core. Didn't match my experience at all.
Eric's specification of solids percentage cleared it up very nicely.
	I couldn't find any listing on labels or web pages for the lacquer I have,
so I did a real simple test. Filled a soda bottle lid with lacquer and
weighed it. Let it sit a couple days and evaporate, and weighed it again.
Weighed an empty lid. Did a wee bit of subtraction and division. Pretty
simple math, pretty simple way to find out.
	When doing the math for dilution, remember to include the ":1" in the
calculations. IOW, 3:1 is a total of 4 parts. So if the "1" is 12% solids,
diluting it with 3 parts thinner gives you not 4% but 3% solids.
	I don't think you can gauge the desired dilution by how it penetrates.
Well, maybe with a lot of experience you could get a sense of how fast the
material moves, but anything in the range of 3% to 10% solids would
penetrate all the way, and pretty fast. BTW, I like an idea Kent Webb gave
me: apply the first dose using a tray filled with solution. Lay a section
of hammers in it until drenched, then move to the next. It's a good ten
minutes faster than squirting each hammer individually. Take that ten
minutes and have the beer you deserve <g>.
Regards
Fred Sturm
University of New Mexico
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