Posted by Ron Norwood on January 17, 2004
Mike JacksonI found this today, Interesting site, and something I have never heard of. Click the link below.
Ron Norwood
(host note: Ron missed the link on his first try and I combined his two posts together here -mj)
Pat Mackle's Comments on Re-using Hide Glue
http://www.sandcarver.org/chipping.htm
I hope Ron didn't mind me combining his two posts. Unfortunately, the post will be above Danny's comments, but it will be cleaner for the future!
Pat Mackle knows a lot about glue-chipping. Maybe we just have to hang around him more to see what other morsels of information fall off him. Re-using the glue makes sense if it helps make chipping better, even if it adds to time and energy. Having never done it, I'd initially wonder if you could reuse it and still squirt it through the little squeeze nozzles on the asphaltum method?
Lastly, I am constantly amazed by the information that is stored throughout the vast Internet. Some of the information comes easy, but little pages like Pat's seem to take a little more effort to uncover—probably comparable to a '48er gold panner when he turns over a small stone to find a shimmering nugget.
Mike
Pat Mackle
Yes, its true animal glue is useable over and over. Think of it as a sponge, it soaks up water and evaporates it into the air over and over again. Lucky for us, unlike a sponge it sticks like heck to glass so as it dries and shrinks it pulls the glass up with it. I believe that I still have the notes that were passed down from a decendent whose father worked for Rawson & Evans. In the notes he states that the glue be reused and new glue added only as needed as the glue became better with use. I reuse my glue by placing the chips in a trash can and mashing them with a wooden pole. Most of the glass separates to the bottom as fine whitish chips. The remaining glass on the chips settles out after the glue is remixed with water and reheated for chipping.
I also do not store the ready glue in the refridgerator. Instead I leave it in the pot and heat it at least once a week which I've found keeps the mold at bay. If it does mold up, I just reheat it and skim off any "plants" with a piece of window screen. The glue can then be placed into a squeeze bottle.
On another point. I've noticed that while mixing up used glue (which still has glass adhered to it, altering its weight) and continueously opening up the glue pot causing evaporation) that I began to wonder just exactly how precise is the water to glue ratio that I had so carefully weighed out when first mixing new glue.
The answer was to fabricate a viscometer. Basically a 3" PVC pipe cap with a 1/4" hole drilled in the bottom. A dip into the glue pot at 150degrees would drain the cup at about 12 seconds. This way I can add water to the glue pot that is lost through evaporation and also get a pretty good idea of the water ratio when mixing up used glue containing glass chips.
In recent experiments with different grades of glue and cooking them over and over I may have discovered my first difference between reused and fresh glue. Maybe others will see this and support it. That being that reused glue seems to lose the immediate gelling properties upon cooling that fresh glue has, allowing it to level out more evenly and thus chipping more evenly.
Pat
Denver Chapter of the Letterheads