Pyrocat HD mixing and developing practices...

[electricphoto]

Hello.

I just ordered some pyrocat hd in the powder form. I'm used to mixing and getting the right temps to get the solution dissolved, but the safety warnings are sort of scary.

Lots of people here use it. Do you use rubber gloves? Are fumes and ventilation a concern? Just looking for peoples experience and practice in mixing and processing with pyrocat HD.

Thanks,

[jp]

I'd suggest mixing it in the garage or outdoor, I wouldn't want the powder spilled in the darkroom. Once it's mixed, fumes/ventillation are not of concern. I generally buy the liquid versions, but plenty of people here mix it themselves.

[Michael R]

Don't be scared, just careful, particularly handling catechol (that's the relatively nasty compound in the Pyrocat mix). Gloves are always a good precaution. Follow the directions and don't rush. Catechol has a high vapour pressure, which is why you'll smell its characteristic odour as soon as you open the bag. For that reason it would be best to mix it in a ventilated area. Since you have a pre-measured "kit", mixing is easier and exposure to chemicals is reduced because you don't have to weigh your own bulk chemicals (ie less handling).



Hello.

I just ordered some pyrocat hd in the powder form. I'm used to mixing and getting the right temps to get the solution dissolved, but the safety warnings are sort of scary.

Lots of people here use it. Do you use rubber gloves? Are fumes and ventilation a concern? Just looking for peoples experience and practice in mixing and processing with pyrocat HD.

Thanks,

[Dennis]

When I process my sheet film by hand in pyrocat I always wear powder free food handlers gloves. Partly to keep the chems off my fingers and partly to keep my fingers off my film. The gloves I use allow me to have a good feel and grip on the film and they are cheap.
Dennis

[Jim Noel]

Don't be scared, just careful, particularly handling catechol (that's the relatively nasty compound in the Pyrocat mix). Gloves are always a good precaution. Follow the directions and don't rush. Catechol has a high vapour pressure, which is why you'll smell its characteristic odour as soon as you open the bag. For that reason it would be best to mix it in a ventilated area. Since you have a pre-measured "kit", mixing is easier and exposure to chemicals is reduced because you don't have to weigh your own bulk chemicals (ie less handling).

There is no catechol in Pyrocat HD. It uses pyrocatechin. If you are not used to handling these superlight powders I suggest you wear a dust mask. Instead of dropping the powder from above, put the spoon close t the surface and drop it in slowly and carefully to prevent the dust escaping into the air. I use a 5 liter beaker to mix one liter of Pyrocat "A".

[sanking]

"There is no catechol in Pyrocat HD. It uses pyrocatechin."

To clarify, catechol is a modern name of pyrocatechin (pyrocatechol), the developing agent ortho-dihydroxybenzene.

Sandy

[Michael R]

There is no catechol in Pyrocat HD. It uses pyrocatechin. If you are not used to handling these superlight powders I suggest you wear a dust mask. Instead of dropping the powder from above, put the spoon close t the surface and drop it in slowly and carefully to prevent the dust escaping into the air. I use a 5 liter beaker to mix one liter of Pyrocat "A".

Catechol is the compound. You can use older terms such as "pyrocatechol" or "pyrocatechin" if you prefer, as long as you don't confuse them with pyrogallol.

There are different nomenclatures for these compounds. The scientific name for catechol can be 1,2-dihydroxybenzene, or 1,2-benzenediol, or ortho (o)-dihydroxybenzene, etc. Pyrogallol would be 1,2,3-trihydroxybenzene, or 1,2,3-benzenetriol etc

[Steve Sherman]

Hello.

I just ordered some pyrocat hd in the powder form. I'm used to mixing and getting the right temps to get the solution dissolved, but the safety warnings are sort of scary.

Lots of people here use it. Do you use rubber gloves? Are fumes and ventilation a concern? Just looking for peoples experience and practice in mixing and processing with pyrocat HD.

Thanks,

When mixing the A portion I wear nitrile gloves and a high quality respirator. The Pyrocatechin comes in decent size flakes and is only reduced to powder at the bottom of the container so there is never a cloud of powder as it is inducted into the 125 degree water. An FYI, I dilute the Phedione with a small amount of alcohol as it goes into solution much easier than with ordinary water. Then combine with the larger solution to complete the mixing process.

[Jim Noel]

Catechol is the compound. You can use older terms such as "pyrocatechol" or "pyrocatechin" if you prefer, as long as you don't confuse them with pyrogallol.

There are different nomenclatures for these compounds. The scientific name for catechol can be 1,2-dihydroxybenzene, or 1,2-benzenediol, or ortho (o)-dihydroxybenzene, etc. Pyrogallol would be 1,2,3-trihydroxybenzene, or 1,2,3-benzenetriol etc

That is what I meant. I mixed up and should have differentiated between pyrocatechol and pyrogallol.
Thanks for the heads up.

[electricphoto]

Thanks all for the tips - really helps. Now to do some processing.

[Willie]

When mixing the A portion I wear nitrile gloves and a high quality respirator. The Pyrocatechin comes in decent size flakes and is only reduced to powder at the bottom of the container so there is never a cloud of powder as it is inducted into the 125 degree water. An FYI, I dilute the Phedione with a small amount of alcohol as it goes into solution much easier than with ordinary water. Then combine with the larger solution to complete the mixing process.

Do you count the alcohol towards the total liquid or does it evaporate out of solution once mixed?

[Steve Sherman]

Greetings.
I only use 2-3 ml of alcohol to dilute the Phendione and then add to the volume of water in the sequence recommended. Bringing the final volume of solution to 500ml

Cheers.