Fuming Box Design

[Jon Lewis]

I have been thinking a lot lately about a fuming boxes and how I want to build mine. My first tests will (as I’m sure you all know) be with 2 1/4" square plates in my medium format camera. I would also like it to be able to handle up to 4×5. I picked up a Pyrex dish that is about 6.5" x 8.5" x 2.5" and have worked up a fuming box around those dimensions. The one thing I’m worried about is whether the plate is going to sit too high above the iodine. Right now I’m planning on having it sit about 3.5" above the bottom of the dish. Is that too high? I saw somewhere that the plate mustn’t sit too high or it’ll take forever to sensitize. ” title=”Confused” />

It’d also be interesting to hearing about other people’s fuming box designs or problems with their current designs or if I had a million dollars to spend of a fuming box I’d …

[jdanforth]

This is a really great topic. Thanks for starting it.

I use the Pyrex 11-cup dish for my boxes although I need to upgrade to something larger since I’m doing 8×10" plates now.

The simplest design is to just slide the plate over the iodine using the top of the dish as the guide rail. Easy! The height is just fine and it only takes a while to sensitize when it’s cold in the winter.

Your design is elegant and will work well. My older boxes don’t use a lid; instead they use a two-slide system. There are two solid slides that go over the tray when the box is not in use. One is wood; the other is Lexan. When in use I remove the wooden slide, tilt up the Lexan slide, and insert the plate carrier. Though it’s inelegant this process maintains a reasonably good seal over the tray.

Now… the million dollar question. I’ve been working on a box off and on for a few months now. The long sides are walnut and the short sides are white ash. The box is joined with dovetails and I’m thinking about engraving Louis Daguerre’s portrait on the lid. There is going to be a ring of inlaid amboyna burl at the level of the slide carrier. Nice, eh?

[CasedImage]

The fuming boxes I had made by Ivan Rose, which you can see in the galleries section, work well but have a slight flaw. Ivan put access crescents in the plate holding sections – so the plate could be lifted up. I use a suction hand pump to lift my plates as they are clad plates and aren’t heavy electroplated, so the crescents aren’t necessary. However they let the fumes flow over the edge of the plate where they are. This wasn’t a problem with just Iodine and Becquerel but Bromine being much more reactive leads to a unevenly sensitised plate.
For design of fuming boxes I like the old run through design of vintage american fuming boxes. Check the galleries section for a new gallery – "Fuming boxes – old and new"

www.CasedImage.com

[dagist]

Jon,

In answer to your initial question, there’s no need to keep the plate close to the iodine crystals in your sensitizing box; 3.5" is an excellent distance. It will not "take forever to sensitize" (30-40 seconds will probably be average) and the increased volume of iodine-rich atmosphere in the box, should allow for less variation in time when sensitizing several plates over a short period of time. My boxes are even deeper and accommodate plates from 2.5" x 2.5" to 8" x 10".

Also, you should consider designing your box with a sliding-insert design (Mike Robinson’s is quite elegant and efficient) so that no fumes escape when you slide your plate over the crystals. This will allow for consistency in sensitization, otherwise, as soon as you lift off the top of a box that doesn’t have a sliding insert, most of the concentrated iodine fumes will escape into the atmosphere of your room.

Good Luck,
Rob McElroy
Contemporary daguerreotypist
Buffalo, NY

[Jon Lewis]

Thank you for your reply Rob! My design is similar to Mike Robinson’s (and several others I’ve seen) in that there will be a piece of glass that slides in on that bottom rail through the front of the box. This will allow me to place my dag plate in the square hole (seen in the left image) then remove the glass plate to expose the plate and then replace the glass when I’m done. The hardest part right now is trying to get an iodine tight seal between the sliding glass and the dish. Eventually I’d like to build (or obtain) a box that allows for larger sizes (perhaps even up to 16×20! ) but for now I’m restricting myself to this size until I start getting images. Plus it’ll take less crystals.

[jdanforth]

Jon Lewis wrote:(perhaps even up to 16×20! )

I just accepted a commission for an 11.5" x 11.5". It’s going to be fun on a bun!

[Jon Lewis]

Well here it is! ” title=”Very Happy” /> It’s not a beautiful work of art like those in the gallery but I think it’ll work well. This is the first thing I’ve build out of wood since I was a kid so I had a lot to learn and as you can tell from the pictures, I still have a lot more to learn. Regardless, I’m very please with my small accomplishment and it’s one more step to a daguerreotype!

fuming_box_1.jpg

fuming_box_2.jpg

[CasedImage]

Now thats dedication! Well done Jon. I might suggest some modifications – router the edges of where the dag plates go in, so that its easier to lift the plate in an out of the lid. Also a layer of varnish on the interior of the box will extend the life of the box – slow down the Iodine fumes eating into the wood.

www.CasedImage.com

[Jon Lewis]

Thank you for your suggestions, I will implement them this week! I knew the iodine would affect the wood but I wasn’t sure there was much that could be done about it.

Suggestions are very much appreciated, I am very new at this and I’m charging ahead somewhat blindly. I’m sure there will also be things I want to change once I start using it and version 2 will look and function better.

[Andy Stockton]

Do you recommend any particular type of varnish? I am most familiar with modern polyurethane varnishes but don’t have any idea how they react to iodine.

[CasedImage]

My fuming boxes have shellac but I think polyurethane varnish would be fine.

btw, there is a test for your glass dish and cover glass, which both should have a ground glass surface where they meet, for a good seal. Place a small piece of burning paper in the dish and place the cover glass on it. The flame creates a bit of a vacuum – the cover glass might rattle a bit as the flame goes out. If the seal is good you should be able to pick up the cover glass by the edges and the dish/jar will adhere to it. If it doesn’t you need to ground the two some more to get a better seal.

www.CasedImage.com

[jdanforth]

First, the fuming box is a beauty, Jon! Well done! I think that I’ll experiment with making a similar one out of HDPE, UHMW Plastic, or something similar. I wonder if I do that if I even have to have the glass dish at all? Hmmm.

Alan your suggestion about the burning paper is very clever.

Another design idea that I’ve seen is to place a springy bottom below the dish so that the dish naturally wants to push up against the cover.

[jdanforth]

I forgot to ask if you’d be willing to share your sketchup / CAD files with us. Would you mind? I might just knock together an open source design for a fuming box and cut one out on the CNC.

[Jon Lewis]

Attached is the Google SketchUp file I created. This was the first time I’ve really used SketchUp so I’m not sure if the file was created as well as it could be…

I was planning on putting my glass dish on a springy material in order to give it some extra pressure against the glass. I don’t have much room but a thin foam might work well.

That would be great to make a fuming box with your CNC! I don’t think you’d need a glass dish if it was sealed well enough… though it might be awkward getting the iodine or bromine back out of the box.

[jdanforth]

Cool, thanks Jon. I’ll knock together a CAD file and see what I can figure out. I have 12 dags and 12 cases to make in the next 12 days so I’m a bit busy!

[Mike Robinson]

John,

to get a ground glass seal for your Pyrex jar and sliding lid…..

Step 1. get a section of old emery belt from a large horizontal belt sander and place it on a very level surface. Thick plate glass or a table saw bed. Sand the jar opening edges until you get a level flat surface about 1/8 to 1/4 inch thick.

Step 2. place some valve grinding and water compound between two pieces of plate glass. Rub them together and in a half an hour you’ll have made two cover glass slides.

Step 3. put some springs under the jar to give upward tension and maintain a seal between the glass and jar.

there are some pictures on my website.

Mike

[Andy Stockton]

Mike-

You mention using a water based valve grinding compound. The only kind I have found so far is oil based and is pretty sticky. I have thinned it with light machine oil but it still sticks the two pieces of glass together very tightly. It makes it very hard to move the glass without breaking it.

May I ask where you get your water based compound?

Thanks.

[Mike Robinson]

I bought some valve grinding compound from an automotive store to make a ground glass in 1998.

I put a dime sized shaped puddle of it on the glass and used is like that.

Its ten years old now and most of the oil has evaporated or dried out. I have been using the grit with a spritz of water.

Seems to work fine.

Mike

[CasedImage]

A recent addition to flickr is a set images of a commissioned Iodine box. It is very nicely made but the design leaves me wondering. I think it has been made without a glass vessel to hold the iodine, finding one that will fit will be difficult. Without one the iodine will eat through the box in no time, but since the darkslides are plywood that will happen anyway. Another thing that puzzles me is that it has two darkslides that perform the same function, both below the plate position. If it is for test strips as described it could give a grid of varying iodine exposure, but given there is a airspace between the plate and darkslide it won’t give a defined area of exposure between the grid sections.

http://www.flickr.com/photos/21138021@N06/sets/72157607506611654/

www.CasedImage.com

[CasedImage]

A recent addition to flickr is a set images of a commissioned Iodine box. It is very nicely made but the design leaves me wondering. I think it has been made without a glass vessel to hold the iodine, finding one that will fit will be difficult. Without one the iodine will eat through the box in no time, but since the darkslides are plywood that will happen anyway. Another thing that puzzles me is that it has two darkslides that perform the same function, both below the plate position. If it is for test strips as described it could give a grid of varying iodine exposure, but given there is a airspace between the plate and darkslide it won’t give a defined area of exposure between the grid sections.

http://www.flickr.com/photos/21138021@N06/sets/72157607506611654/

www.CasedImage.com

[Andy Stockton]

Lovely woodwork. It does seem like it will be eaten away rather quickly. Perhaps the user will set a glass dish inside to help a bit. I also have wondered if polyurethane varnish would hold up to iodine fumes. Does anyone have experience with that?

[drdag]

I just sprayed the inside of my Pine box with black aerosol car paint (cellulose). Sometimes I think
too much time can be spent making the equipment look nice ,rather than making equipment that works and spending the time making images.

[Andy Stockton]

I understand your sentiment. It is easy to get lost in the craftsman aesthetic with the equipment and lose track of making the images. I have that tendency.

How is the spray paint holding up? I have never heard of cellulose paint. Do you recall the brand?

[jdanforth]

I’m always embarrassed when a student comes to my studio. My equipment is so fugly. My main sensitizing box is 1/2" poplar built around the Pyrex dish. I used the handy but ugly butt-joint and there’s dried glue drips going down each side.

In my "spare" time I have been cobbling together this really attractive sensitizing box with pretty dovetails, inlay, etc. but I never can find the time to finish it. Perhaps on Sunday.

My "darkroom" is a corner of the studio that I have masked off with thick black plastic painter’s drop-cloth. All of these little quirks serve to remind me that daguerreotypes can be made with fairly loose standards and still come out looking great. It’s no Castle Daguerre but it’ll do. ” title=”Smile” />

[drdag]

In reply top your question Andy, cellulose is just ordinary car touch up spray from the auto accessory shop.It is now only available for classic cars in the uk as it is unenvironmentally friendly. I think any old spay paint will do just to seal the wood.It seems fine after 1 year, I do not leave my iodine in the box when I am not making images.

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