Diazo-Sensitized Carbon Transfer

[gmikol]

Thanks anyway, PE...my copy of "Light Sensitive Systems" is over my head.

--Greg

 

[gmikol]

[...]start a new thread that doesn't say "= Failure"; though I guess anybody really interested would probably get past that title and read on.

holmburgers has a point...

I've asked the mods to rename this thread "Diazo-Sensitized Carbon Transfer" so that we can keep all the info in one place.

--Greg

 

[mdm]

I use a 300w Osram UltraVitalux bulb, which is what I started with 18 months ago, it is fast but no longer suitable, I am building a bank of BL tubes so I can make bigger prints.

The recieving support in Tod Ganglers video is probably mylar sized with dichromated albumen. The process is described in a file on the Yahoo Carbon Forum by Gary Baker Dead Link Removed

The Kiwo agents are trying to get me some sensitiser seperate to emulsion, if it happens it will take time as it will probably have to come from the US.

I can post my wedges sometime today but they are stained yellow, I have no way of trying the clearing baths recomended until I get some potassium permangenate.

Note I made all my 4 wedges within 24 hours of pouring, I dont know how long the tissue will last.

David

 

[mdm]

Here are my wedges.

 

[gmikol]

Thank you so much for your contributions to this thread, David.

A couple of random points:

1) The middle one is the one you transferred to the back of RC paper?

2) Even at 20 mins, it seems like it could use a little more exposure.

3) Do you have an MSDS for the sensitizer? The Kiwo documentation describes this as "Diazo Sensitizer #14", but I can't find any MSDS for this. It would be nice to know what the actual chemical is. I suspect it is likely this one: 4-DIAZODIPHENYLAMINE/FORMALDEHYDE CONDENSATE HYDROGEN SULFATE (CAS# 41432-19-3) since that is what is in Kiwo sensitizer #1-#11.

4) Can you post the 2ml/50ml wedges as well, for comparison?

--Greg

 

[mdm]

theese are the 2ml/50ml glop wedges, 2ml=~0.69g diazo, I made a mistake there. The 20minute 4ml/50ml wedge is very similar to #3 wedge above, slightly paler. I want to try printing with a lower concentration of diazo in the tissue when I get a chance to make more.

It needs more exposure to get the black I get through pictorico with 8min and 2%AD. I will try my last strip of 0.69g/50ml glop with a 35 min exposure and see. Dmax is no problem with colour like Tod Gangler or multiple transfer like Gordon Chapple, to me it seems a small price to pay for the health and environmental benefits, multiple transfers open a whole new world of creative possibility so it may actually be an advantage.

It transfers very easily and I have had no problems really.

I didnt get the MSDS and have no idea what is in the sensitiser, but my gut feeling is that all of their granular sensitisers are the same and the number is used to refer to different weights of diazo, they must be using diazo concentration to control contrast, so different numbers probably only refer to different diazo concentrations in the final mixed emulsion. I could be wrong though.

ok 35 min gets me another stop but still not a black. the good news is that it seems to still react fairly linearly with a stop of exposure giving a stop on the wedge, there is really only a stop and a bit left before I run out of stepwedge. I will scan the wedge when it is dry.

The bad news is that the kiwo ulano screen printing agents here in NZ are unable to supply me with the sensitiser on its own, I even gave them links to my carbon prints and others on unblinkingeye and colourcarbonprint.com and Sandy Kings article and Tod Ganglers videos so they know what I am up to.

 

[CMB]

The effort you guys are putting into finding non-toxic alternatives to dichromate is important. Not being a chemist, I had to search blindly (otherwise known as trial and error) for quite a while until I found something that worked. Unfortunately, the factory that manufactured the sensitizer blew up several years ago. Here's their product info:

 

[mdm]

So thats why they wont sell me a kg of the stuff! Thank you.

Anyway 60 minutes darkens things up substantially but only gets me 1 step extra, I reach paper white, or in this case yellow, on step 18. Tissue is all finished now. compared to the same tissue spirit sensitised with 2%AD its about 3 stops or more slower.

Fairmount Chemical Company still exists, anyone care to ring them?

 

[gmikol]

Fairmount Chemical Company still exists, anyone care to ring them?

I'm not so sure...I can't find a company website. There doesn't seem to be any real information about them on the 'net, and I found one note that mentioned an involuntary Chapter 7 bankruptcy filing (asset liquidation) some time in 2007.

Thanks for posting the data sheet, CMB. Seems you found a chemical what worked pretty well...

--Greg

 

[mdm]

How about Hunt Imaging? Dead Link Removed

 

[mdm]

Bingo.

Dead Link Removed
Contact details here Dead Link Removed

If we can get someone, perhaps Artcraft to stock it, that would be perfect.

 

[Photo Engineer]

Guys;

It is quite clear to me why the plant blew up!

Good luck, but my advice is to be careful, be very very careful!

PE

 

[mdm]

If it is a threat to safety then its a no go, however screen printers have small amounts of sensitiser shipped to them routinely, with no problems, so it may be workable.

 

[Photo Engineer]

This is an azide or N3 compound. Beware of all azides. They are usable but very touchy. I don't like to handle them at all.

PE

 

[mdm]

You're the expert. Thanks for your contribution. Perhaps there is another alternative? If screen printing sensitiser works ok, then it may be better, just a matter of finding a scource.

 

[mdm]

more wedges, 35 min and 60 min exposure and a sample of the sensitised tissue for a deep black.

 

[CMB]

It is quite clear to me why the plant blew up!

Good luck, but my advice is to be careful, be very very careful!

PE





You are perhaps confusing the manufacturing of azide compounds (a dangerous process) with the use and storage of the finished compound.

Hardnener #3 required no registration/regulation with the U.S.Dept of Transportation and was relatively inflammable and safe to use. I don't know if the plant blew up making this chemical or another.

 

[mdm]

This is what wikipedia sayes about azides. Mr Mowrey may be right.

"Azide is the anion with the formula N3−. It is the conjugate base of hydrazoic acid. N3− is a linear anion that is isoelectronic with CO2 and N2O. Per valence bond theory, azide can be described by several resonance structures, an important one being N−=N+=N−. Azide is also a functional group in organic chemistry, RN3.[1]

Sodium azide is found in automobile air bags; it decomposes on heating to give nitrogen gas, which is used to quickly expand the air bag. The antiviral drug zidovudine (AZT) contains an azido group. Some azides are valuable as bioorthogonal chemical reporters."

 

[CMB]

Hardnener #3 required no registration/regulation with the U.S.Dept of Transportation and was relatively inflammable ...

I meant to say it was neither listed as an explosive or flammable material nor was it considered dangerous by our manufacturing (coating) facility and required no special handling.

 

[Photo Engineer]

I suspect that the formalin addict or the zinc complex of these reduces their instability.

Remember, a compound that is not explosive or flammable is not necessarily stable. These azides have a finite lifetime I would think. And, Sodium Azide is indeed explosive when heated.

PE

 

[mdm]

I am told it is a class 4.1 (flammable solid) so definately not possible to ship overseas, it has to be kept very cool, in a fridge. It may be possible for people in the USA but the safety aspect is yet to be fully explored, at least by me.

http://en.wikipedia.org/wiki/HAZMAT_Class_4_Flammable_Solids

Probably best to stick with some sort of screen printing sensitiser.

 

[mdm]

The clearing bath quoted earlier in this thread works fairly well. Amazing to watch the wedge go purple in the 1st bath and then raidly clear in the last, leaving very little stain behind. The RC paper I used seems to hang onto a faint yellow even cleared twice. The relief is very fragile in there and is prone to rubbing off/dissolving away so times quoted are probably the maximum. I will post a cleared wedge when it is dry.

David

PS Stick to the times for each bath, 1 minute, no agitation required I dont think, dry before washing I think or the highlights will wash away. Any residual yellow stain goes with the wash water. Its possible I am using the wrong concentration Sodium Sulfite, I am using anhydrous.

 

[gmikol]

David, I'm wondering if a lower concentration of sensitizer in the glop might help limit staining, even though it would probably increase contrast and lower speed. Less dye hopefully would mean less staining. I'm also wondering if a pre-soak (prior to clearing) would help clear more of they dye stain.

Also...did you check to make sure the table salt you were using was non-iodized (& that there were no other additives, like to prevent clumping)? I don't know if any of those things could have interfered with the clearing process.

--Greg

 

[mdm]

Sometime next week I will do a pour with less diazo sensitiser in it.

Clearing, drying, washing leaves a yellow stain but maintains the integrity of the transfer. Clearing and then washing works about the same.

2 clearing cycles and then immediately washing cleared the stain but I left my wedge soaking in the sink and when I came back 2 hrs later it had started to dissolve.

There is a balance that will work. Stain may not be a problem with some supports.

This is RC paper I am working with and only the coated side stains, not the back. Something in there is reacting with the diazo. Gelatine sized watercolour paper will probably be fine.

I am too busy now to spend time on this, but it is a workable option and I hope someone will be able to repeat my results soon.

Yes, non iodised salt was used.

 

[happyjam64]

I am by far no expert, but does anyone think that Titanium Dioxide could help decrease exposure times? According to the wiki on TiO2 "Titanium dioxide, particularly in the anatase form, is a photocatalyst under ultraviolet (UV) light."