U of S | Mailing List Archive | alt-photo-process-l | Re: Mixing Ratio: 14 Baume Gum From Powder

Re: Mixing Ratio: 14 Baume Gum From Powder

Hi Michael,
The answer to your question is to buy a $30 baume meter from Cole Parmer and also a test tube tall enough so it can be submerged mostly (about a foot). I've been communicating with Art Chakalis about this and he has a measure of 288g gum to mix up a liter of combined solution. I found with my gum arabic approximately 840ml water to 288 made a liter. But Art pointed out that different gums have different moisture content so that this measurement is never exact, hence the baume meter. But about 280-320g gum = 14 baume.

SO, I was on a wild goose chase about strengths of gum throughout history and found that they varied from 10% to 50% gum! Take your pick.

----- Original Message ----- From: "Michael Koch-Schulte" <mkochsch@shaw.ca>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, August 28, 2007 11:01 PM
Subject: Mixing Ratio: 14 Baume Gum From Powder

How do I mix ~14 baume gum from powder? It's not 1g. gum to 2 ml of water
that's about 18 baume so I've read....and I'm finding it too thick? A
sub-question might be how could I water down a 1:2 mixture. So what do
people do 1:3? 1:4? I read somewhere on the list someone (Guido) was using


RNP Arrays: Open Source Digital Negative Project