FumeHoods for Dags.

[Barrutia]

I´m planning to build a homemade fumehood for Daguerreotypes.
Any recomendations regarding materials and systems?.
Do I have to build two different hoods and exhausts one for Iode (maybe bromine in the future) and the other for Mercury?
Any online links with examples and photographs?.
Thanks !

Agustin Barrutia

 

[JG Motamedi]

Agustin,

Don't mess around with a homemade fumehood unless you know EXACTLY what you are doing. By asking the question, I think I can safely assume that you don't know what you are doing.

Fumehoods are a lot more complicated than a darkroom exhaust fans and a lot more critical. A few feet of tubing, the location of the exhaust, the type of fan, the size of the opening, and even the placement of your arms can mean the difference between mercury fumes escaping into your darkroom and your body, or being safely exhausted (and probably deposited into the body of a tuna fish). A few years ago a daguerreotypist in Australia or New Zealand critically poisoned himself because of a poorly designed fumehood.

Either buy a laboratory grade fumehood or find someone to build or design one for you.

 

[Barrutia]

Thanks Jason for your warnings.

Actually I thought of contacting some chemistry lic. here in Bs As that could tell me what precautions to take when dealing with iodine and Mercury.
I wasn´t thinking of building the hood myself neither! My skills in construction are quite poor.
But I thought it might help to consult about hoods here in the forum.
Jason, what system do you use?.
Should I use 2 hoods separated? one for Iodine and the other for mercury?
I have no idea how much a fumehood costs.


Thanks once again

Agustin

 

[livemoa]

Agustin,

A few years ago a daguerreotypist in Australia or New Zealand critically poisoned himself because of a poorly designed fumehood.

QUOTE]

I think it was here, and when he got to the hospital nobody believed him! Or so the story goes.

As an aside, the expresion "Mad as Hatter" comes from the days when hat makers used mercury when they were making hats and subsequently suffered brain damage.

 

[jamnut]

At work, we use Labconco Laminar flow hoods and fume hoods. They aren't cheap, I think our fume hood cost $4000 six years ago, this is not including the cost of the ventilation system.
This may give you an idea of what you need:

http://www.labconco.com/pdf/fume_hoods/select_fume_hood.pdf .

 

[JG Motamedi]

... Jason, what system do you use? Should I use 2 hoods separated? one for Iodine and the other for mercury? ...

I used a small labconco fumehood which I bought used on eBay. It wasn't expensive, but I had to rent a truck to move it, convince a few friends to help me, and spent quite a bit having it inspected after I installed it.

However, about nine months ago a tall building went up next door to my studio, which meant that I could be exhausting Hg and other nasty fumes into somebody's living room. I haven't been able to make a "traditional" since then, although I have made quite a few Becquerel. I have been putting most of my spare time into learning wet-plate collodion. Not quite as appealing, beautiful, ethereal, and esoteric as dags, but a hell of a lot easier and safer.

Yes, if your hood is large enough you can use one for Hg, I2 and Br2.

Also, the pdf file which jamnut linked to in the above post is excellent. Thanks!

 

[Dan Dozer]

While I know that there is a lot about photography that I don't know(Deguerreotypes are one of them), I do know a lot about Chemical fume hoods. I am an architect who specializes in designing chemical use laboratories. The reference that JMNUT gave you to Labconco is a good one, and I advise you to look into their website carefully. They are one of the largest manufacturers of chemical fume hoods in the US, and their website has a lot of good reference information.

The important thing in looking at what kind of hoods are best for your work is the nature of the chemicals that you are using (are they heavier or lighter than air for example). Mercury can be extremely dangerous and extreme care should be taken in using it. I strongly advise seeking the advice of the experts in chemical exhaust market before making any decisions. The fume hood engineering department at Labconco is very good and I'm sure would be happy to answer your questions. I don't know who you may have in Argentina, but some of the large US fume hood companies do have offices worldwide - Labconco does have representation for Central and South America listed on their website.

The design of the fume hood itself has a lot to do with the effeciveness of the hood. Aerodynamics in the design of the airslots, plenum spaces, and the shape of the frame around the front opening all contribute to the effective design of the hood. By all means, do not use either an overhead canopy hood (like the hood over your kitchen stove, or a back draft exhaust source behind your workspace. Neither are designed to capture chemical fumes like you are considering and neither will be particularly effective.

One hood type that Labconco makes that you might consider is their Protector XVS and VS models - you can find it all on their website. They can be mounted on a stand frame or just sit on your bench top. They are a light duty hood and are effective in safely exhausting chemical fumes from sources using smaller amounts of chemicals. These would also be considerably less expensive than large full blown fume hoods. However, as I said, you should contact someone like Labconco and talk things over with them.

Hope this all helps