hide glue question

[sunburst]

It occurred to me that hide glue has been around a lot longer than electric glue pots, crockets, and, for that matter, thermostats.

How did Stradivari keep his glue between 140 and 160 degrees?
I thought some of you violin builders of historians might know of a traditional, low tec way to heat hide glue that works.

[Rob Powell]

Not sure how Stradivari did it but there were thermometers around during his time just not calibrated to the scales we currently use.

[Darryl Wolfe]

Good question...I would suspect something very akin to heat source/system for distilling spirits...aka..a brewery

[Dale Ludewig]

Darryl- that might be quite the insight! What if they were making a little distilled beverage where if the tempature (as I think it would be, having never done it myself) would be right in that hide glue range. Just over boiling water temp...... This could lead to all sorts of new theories on his finish and how he achieved it.

Plus in that "magical" state, who knows what else he might have thrown into the pot of varnish? It makes the mind reel.

[Jeff Baldwin]

I am reminded of a trick that chinese cooks use. When deep fat frying
they determine the temperature of the oil by placing a bamboo chopstick
into the oil and touch the side of the wok. When the oil bubbles around the
contact point of the chopstick and wok...the oil is ~350 F- just right for
frying. I do not think that everyone how has used this trick would know
the finite temperature of the oil. They only need to know that the appropiate
temperature for deep frying has been reached. Their tool a chopstick, their
marker bubbles. Our 21st century tool is a thermometer, the marker analog or
digital output.

I am not saying Stradivari used a chopstick to determine temp...but Ill bet
there were characteristics of the proper temperature of the glue that were exhibited that a builder in the times of Stradiveri could easily recognize and use. An interesting questiion to research...

[Lane Pryce]

John that would be a question for Michael Darnton. He occasionally posts here and he is recognized as a leading builder and historian. Steve Perry may have some insight too. Have you ever wondered what kind of tools Antonious Stradivarious might have used? Lp

[s1m0n]

I test the temperature of a pre-heated frying pan by tossing in a sprinkle of water. How it reacts tells me if the pan is the the right temperature for whatever I'm about to cook.

[Chris Burt]

I've read most of the main Strad references printed in English. I don't remember reading anything about his gluing techniques. The index of the Hills' "Antonio Stradivari" contains no reference to glue.

The Catalogue of Stradivari relics that are contained in the "Ala Ponzone" Civic Museum of Cremona (listed in the back of Saconni's "The 'Secrets' of Stradivari,") contain no reference to tools related to gluing.

I don't see any reference to gluing tools in Pollen's book on Strad forms.

I don't see anything on glue in the index of the Biddulph Guarneri book. Perhaps Michael Darton can point out something I've overlooked or forgotten.

It's fun to look at the pictures of the really cool thumb planes in the back of Saconni's book and imagine using them or using the scrapers made from saber and stiletto blades that are mentioned but not shown. I visited the museum once, was overwhelmed, but remember little about its contents.

[Desert Rose]

You can be sure it was a simple double boiler, and you can be sure also that he likely didnt use a thermometer but had practical ways of checking and knowing the working temperture, like the chopstick in the oil technique for Chinese cooks

Scott

[resonant68]

Back when I was in the Industrial Supply buisness our bearing suppliers always taught us thet when inspecting a bearing for possible failer that if it was too hot to hold your finger on,then it was failing.
They called it the "ouch! factor"......Based on bearings intended for use in ambient temperatures,that is......
Now,I never botherd to actually test my fingers heat tolerance but,just maybe they used a similar method of touch to test the temps of the glue?http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif...or possibly by the viscosity of the glue when heated?http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif?http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif??
Just a thought.

[Bill Snyder]

Since hide glue has historically been used for wood working of all types you may be able to do a little research in other areas than just lutherie to find the answer. How did Chippendale warm his glue - probably using a similar method to Stradavari.
I know this does not answer the question, but it gives another place to look for the answer.

[sunburst]

Curious, that's just the kind of thing I was thinking.
There must have been a reliable way to control the temp without constant monitoring. Seems to me it would have been well known and standard in the various trades that used hide glue. It's the type of thing that can be nearly forgotten when new technology like an electric glue pot comes along, and then with the advent of modern "improved" synthetic adhesives making hide glue "obsolete",...well, we have to rely on books and forums like this to even learn to use the stuff these days, and play historian to figure out how they used to do it.

[Frank Ford]

All these facts and cautions about hide glue are meant for industry, where automatic equipment spreads the stuff on corrugated cardboard, or vats of it stay under heat all week.

It CAN stand a bit of overheating for short periods, it CAN be diluted as needed, etc.

If you keep it hot all day, then you have to keep the temperature down to maintain full strength, particularly if it's reheated day after day. My old pals, Hideo Kamimoto and Mario Martello have built a 40+ year careers on using hide glue in an open jar, sitting in a pan of water on a hot plate. #They say the only temperature control they've ever used is to keep the glue itself from actually boiling. #As the glue thickens, they add a bit of water.

http://www.frets.com/FRETSPages/FieldTrips/Mario/MarioViews/gluepot.JPG