[photolytic]

Currently it is costing me approximately $100 just for the cost of polished copper and commercial silver plating of a whole plate assuming I meet my platers minimum charge of $250 per order. You might be better off buying half plate cladded silver Dags from Mike Robinson (consult his website).
Additional costs depend upon your definition of the etc category. Does it include polishing equipment and cost of fuming, fixing and gilding chemicals as well as mounting and sealing the image behind glass? All these things can more than double the cost. Having made wet plates myself for many years I can vouch for the fact that wet collodion is cheaper, although some equipment such as cameras lenses and plate holders can be used for both processes.

[photolytic]

Hello Simone
Unless you also cleaned the walls of your mercury box, it is puzzling why the temp/time change worked so well.
Perhaps the higher temp allowed refluxing mercury to rinse accumulated polish particles from the walls of the box.
I develop under vacuum for 2 hours at 20C and get no spots if the plates and box are clean.
Best,
John

[photolytic]

Caused by residual polish on plates.
Replace buffing pad material.
Filter mercury.
Vacuum plate holders and fuming trays.
Wipe back of plates with tissue before fumimg.

[photolytic]

Traces of iodine and bromine in the box will erase part of the latent image during the mercury developing procedure.
Nineteenth Century Daguerreotypists sometimes used this procedure to correct for overexposure of a plate.
You really don’t need a box for the iodine and bromine fuming if your boxes are well sealed with a tight fitting ground glass lid. However if you feel you must use the box for fuming, remove the fuming boxes before you put your mercurizer in the box.

[photolytic]

.

Attachments:

You must be logged in to view attached files.

[photolytic]

I used 6 pops (6x 1/250sec) from my 9600ws strobe at 1 meter and f2.8 to get this result on a magenta B-Dag plate. Normally 1 pop is enough on a rose M-Dag plate.

Attachments:

You must be logged in to view attached files.

[photolytic]

Don’t used Bromine on Becquerel plates!

That being said, please see the following post by Mike Robinson from May 11, 2013 at 7:03 am #15953

Mike Robinson

Participant

Bromine in water according to the old manuals is 1 drop in 40 of water.

lime (calcium hydroxide) should be a medium pink through and through. see picture “bromine in lime”

I find silica gel 6/16 mesh the best medium for controlling bromine. I call it Robinson’s Quick.

I discovered this in 2003 and have been using it ever since. Bromine in silica gel should be yellow.
see picture stock/vs/working. When bromine works too slow, add a small amount of stock.

the picture shows how the silica gel is charged.

Mike Robinson

Attachments:

stockvsworking
stockvsworking.jpg

bromine-in-lime
bromine-in-lime.jpg

charging
charging.jpg

[photolytic]

Those 5s -20s bromine times are typical for 20C fuming.
I use 8s -12sec.
Longer first iodine times require longer bromine times.
I don’t know what caused the brownish spot.
Was your fixer fresh?
Did you wash the plate well before drying it?
If you gilded the plate, did the gilding solution dry out on that area of the plate or get too hot?

[photolytic]

I agree with your exposure method.
I expose for the medium shadows or average between the highlight and the dark shadows.
I let the sky solarize to a medium blue.
It looks good and the image is strong enough to see in public with good angled lighting.

[photolytic]

Using hypo crystals is a good idea, much easier.
Your local advice is correct. Your Bromine box is too big and the space between the bromine and the plate is too great. My wholeplate box is only 7cm deep and the glass bromine dish fits all the way to the ground glass seal at the top.
It is too much work to build a new box for every plate size. Build your box with a hard plywood (Oak or Birch)for the largest plate you want to make in the future. In a cooking supplies store find a 5-6cm deep and rectangular glass dish that is just large enough for your intended plates (approx. 18x24cm for wholeplate). Build your box slightly larger to fit the glass dish. You can always add wood shims or a bottom board to make the dish fit exactly later
Sand the top edge of the dish flat so your sliding glass sealing plate fits it. Add some silicone grease to the top of the dish so it makes a good seal with your glass sealing plate.

[photolytic]

Do you ever a swim in a chlorinated pool?
Bromine is frequently used to replace chlorine as a disinfectant in pools and spas.
Those with very sensitive skin may prefer bromine because it generally does not cause as much skin and eye irritation as chlorine sometimes can.

Excess bromine fumes can be reacted with thiosulfate. Place the Br/water container inside another airtight container with a tube leading to a container of sodium or ammonium thiosulfate. Alternately an airlock such as those used on wine
barrels with thiosulfate in the air trap can be used. Do NOT try to neutralize the fumes with ammonia. Halogen fumes (especially iodine) can react with ammonia to form nitrogen tri-halide compounds which can are explode.

Unlike mercury which has no odor to warn you, the odor of bromine is your friend, warning you to avoid breathing the fumes before they reach a dangerous level. The plastic cap on your bromine bottle is probably not resistant to the fumes. Several other writers on this site have found Teflon lined caps that are more effective and resistant to bromine.

[photolytic]

What is the composition of your polishing dough?
Be sure it is for silver, not the base metal type and does not contain alumina.
The air from the air compressor contains moisture and perhaps some particles.

The rotary buffer will remove the scratches better. Afterwards you can clean up the plates with alcohol.
Before gilding the failed image can be removed with a light wipe with a soft dry facial tissue.
The rotary buffer with rouge will do the rest. Then use the ROB.

What type of plate holder do you use on top of your iodine box.
Do not use the camera plate holder as the residual iodine fumes may be absorbed and erase the late image.

[photolytic]

Do you rotate your plates during fuming?
Uneven fuming can be reduced that way.

I see that you are now getting more black spots than white ones on your plates.
You should increase the buffing time or put fresh buffing material on the Random obit buffer to try to eliminate them.
I buff a 13x18cm plate for at least 15min at the lowest speed on the ROB.

The space between the top of your iodine dish and the sliding lid is too great allowing much of your fumes to escape.
Try putting something underneath the dish to raise the level closer to the top of the box.

I see that you do not have enough iodine crystals to cover the bottom of the tray in your fuming box.
A whole plate fuming box should have at least 200grams of iodine. Mine has 400grams.
If you make these changes it would shorten your fuming times.
You say that the longer fuming time doesn’t matter so long as the same color is reached.
However consider this:
The advantage of shorter over longer fuming times is that it makes it easier to remember the progression of the colors.
After a long interval, your memory of the previous color fades and everything begins to look the same.
Longer times make it easier to pass over that narrow window of colors that produces the fastest plates and best tones.

The pronounced bluish color of your images may be because of the moisture in the bromine water.
Dry bromine will lead to more neutral colors.
Remember that you must keep any silica gel mixture in a sealed container away from moisture of it will absorb water.

[photolytic]

Mark Kereun is a very dear friend and I greatly value his suggestions.
I’m not sure what Marc’s fuming box looks like. so my suggestions are based upon the design of my fuming box .
The edge to center iodine color effect should not be a big factor on a well polished plate in a good box.
To distribute the iodine fumes better they should be placed in a flat glass tray,like a cooking dish, not a tall glass.
For long term storage the plastic box will be attacked by iodine fumes and leak.
It is better to have a glass lid, etched like camera ground glass, which slides over the glass iodine tray.
If the iodine box is fitted with a spring pressing the lid down the fumes can not get out.
The color change leading up to first yellow takes place rapidly and can be observer at intervals of a little as 2 seconds. It takes time for the iodine fumes to become distributed through out the box.
The fumes are heavier than air. I sampled the iodine vapor from the top of my box near the plate fuming area, using a syringe and found it contained ten-thousand times less iodine than the concentration at the surface of the iodine crystals as predicted by the vapor pressure charts. Fuming can easily deplete the iodine fumes at the top of the box and Pobboravsky found that it is better to wait between fuming events for the fume concentration to be restored.

Attachments:

You must be logged in to view attached files.

[photolytic]

Same with times attached.

Attachments:

You must be logged in to view attached files.

[photolytic]

You should get 1st yellow (Not a very strong color) in 10 seconds at 20-26C.
You are probably going to the 2nd yellow at 2 min and even 3rd yellow at 5 min.
How much iodine do you have in your box and what are you covering it up with?
Maybe the iodine fumes are having trouble getting through to the plate.

The effect of bromine on the color of the plate is very subtle and is only obvious after a fresh iodine fuming.
If you want to get reproducible results you need to keep notes of the temp,fuming time,and plate colors at all stages.
Only then can you understand why you are getting different results at different times.
Here are the colors of the first cycle of iodine fuming.
If you see colors other than yellow before you get to a strong yellow you are past the first cycle.

Attachments:

You must be logged in to view attached files.

[photolytic]

Because the bromine fuming should be done under weak white light which produces photolytic silver that increases the speed of the plates. As you know the dag developing procedure does not reduce any silver halide like in b/w film for example. The metallic silver in the image comes from the action of the light in the camera plus the action of light during the bromine coating inspections. If you do all your bromine coating in the dark your plates speed will be slower. You should read Barger and White’s book to familiarize yourself with how the process works before you experiment further.
The second Iodine is done to restore the sensitivity of the plate to camera exposure light. The times you are using (20-45s) are much longer than is need for this purpose unless your iodine temperature is very low. (<10C)
Most suggest that the second Iodine should be half as long as the first iodine. Part of the second iodine should be done under white light so you can see the final color of the coating. Only the last 2 to 5 second needs to be done under safelight conditions or in the dark.

[photolytic]

Are you formerly from Portugal like your famous namesake explorer Tristão da Cunha?

As for me I am the one from Chicago who wrote the article to which you refer in your 23 April blog as “Un ricain a fait toute une thèse là-dessus ( à lire sur CDags.com ) “.

Any time over the second iodine down to 2 seconds will do. You can do several times on the same plate by masking part of the with glass over the iodine box. Generally the more time, the lower the contrast and sensitivity

[photolytic]

Thank you for the detailed description of your technique. It has been most helpful.
However both Gregory and myself are concerned that our advice about the bad effects of residual aluminum on the surface of Dag plates has some how been interpreted has a recommendation to use aluminum silicate or Rottenstone to remedy the problem. Our advice in fact is quite the opposite, that you should not use aluminum silicate to solve your problem.
You may be correct is surmising that the problem comes from the silver surface however. Maybe something on the surface of the polished copper underneath the silver that affects the surface above. How thick is the silver.
Here is an SEM image and elemental analysis of the surface of Dag plate provided to me by Daguerreotypist Tom Young of Boulder Colorado. The white spots were identified as alumina. The source of the alumina was apparently the supplier of the silvered plates, Theta Plating of Saint Louis Mo. since Tom Young did not polish this plate with alumina.

Attachments:

You must be logged in to view attached files.

[photolytic]

Mercury splash spots tend spread when the plate is dried and don’t have a black corona like many of those on Titisteph’s plates. Before the plate is fixed some or all of these mercury droplets can be dislodged from the plate surface by holding the plate vertically and by tapping the plate against the inside of the mercury pot.
An accumulation of scum on the mercury surface can cause spots due to a sputtering effect as the mercury evaporates from the surface of the mercury pool at the bottom of the developing chamber. Filtering the mercury will eliminate this scum.

[photolytic]

The key to preventing scratches when buffing silver on the rotary buffer is to use unstitched flannel buffing wheels.
Have you eliminated the possibility that the white spots are mercury mist from overdeveloping?
Have you tried Becquerel developing on iodine only plates?
Did you still get the white spots on B-Dags?

[photolytic]

I use the rotary buffer on every plate but with very light pressure-no scratches.
It is not necessary to use nitric acid-I do not- but I did see it in Daguerre’s manual.
White haze which is almost impossible to remove comes from cyanide plating with not enough brightener.
Platers who specialize in thin silver plating of electrical equipment (1-5 microns),like switches, do not put any brightener in their plating bath to prevent white deposits on more heavily plated objects like 10 -25microns.
This film is extremely difficult to remove unless you buff almost all the silver off.
All platers,like crystofal, who introduced electroplated Dag plates in the 1850’s, used carbon disulfide brightener.
Modern platers sometimes use thiosulfate too.
If your plater is supplying you with dull plate that has been buffed bright after plating may be causing these spots.
With enough brightener the plates should be mirror bright right out the of the plating bath with no buffing.
Is the rubber bulb you used to blow off deposits on your plates clean inside.
An alternate method I used is to buff the plates upside down on a velvet buffing paddle just before iodine fuming.

[photolytic]

I only used aluminum silicate before I bought a high speed rotary jewelers buffing machine.
Now in stead I use that buffing machine @3400RPM with stick rouge-in-wax for the first polish.
After that I clean off the plate using soft tissue soaked with alcohol.
Then I buff with powdered rouge using my random orbital buffer with 18%silk/82%rayon velvet on the sponge pads.
Then I use another ROB pad with powdered lamp black on it.
Finally I used a clean velvet covered ROB pad to remove any lampblack.
Be sure and wipe the backs of the plates to remove and residual polish there.

Attachments:

You must be logged in to view attached files.

[photolytic]

I can’t answer in French like Gregory but I would be more specific and ask if you use “rottenstone” which is aluminum silicate in your rough polishing before rouge. This can leave small white particles on the plate. The people who make and polish the plates you buy may have used alumina containing polishes. Have you tried cleaning the plates with some dilute nitric acid like they did in the old days?

[photolytic]

An interesting explanation Mike.
Volker Rose showed me the micrographs he’d made with Vicenzi using Argonne Labs advanced photon beam X-rays.
The mercury inside the particles was clearly visible in old 19th Century Dags too.
You’d think that the heat generated by the x-rays impinging on the Dag particles would have also caused them to explode like popcorn too.
Daniel Carrillo says that B-Dags also brighten upon heating.
Since they have no mercury inside them what do you think is happening here?
Perhaps mercury is not the only explanation for the popcorn effect.

Attachments:

You must be logged in to view attached files.

[Author]

Posts