[Pobboravsky]

Alan, I apologize for not making myself clear. I am not questioning whether your Hg’er is beautifully designed and fabricated — however it is out of reach financially by most people who would like to buy a unit. It may very well be that a PROFITABLE “starving artist” Hg’er may not be achievable. But that is where the challenge lies. [During your time in the US you likely heard Garrison Keillor’s monologues on The Prairie Home Companion radio program. You may remember the 93 year old Senator B. Thorvaldsen, one of the fascinating characters that lived in Lake Wobegon. Senator is his first name. He was at a gathering and in conversation with someone who said: Senator, what you need is a good woman. His reply was: I don’t care about good anymore. Your present Hg’er is more than — good.] What I’m suggesting is the equivalent of a Ford Model T that is affordable and meets the need – does the job. Irv

[Pobboravsky]

Alan, it is a great challenge to design a low-cost Hg’er. The 19th-century cast-iron, inverted, hollow pyramid design does this brilliantly and compactly. I store my 5×7 Hg’er in a surplus 50-caliber ammo box (bought on the web).(My hg’er is not cast iron.) There is a need for a “Starving-Artist” version of a half-plate size unit. Without any change in design the same unit could be bought either w/ or w/o a temperature controller. The thermometer or the thermocouple need not have its end sitting in the Hg. It could just as well be situated in a hole drilled in the cast iron – even close to the top of the unit. Just some thoughts. Irv

[Pobboravsky]

Alan,

Congratulations on the design and fabrication of the mercury developing boxes.  They are beautiful!   Have you arrived at a price in US$?  Please consider a  mercury-tight container to safely store the mercurizer when not in use.   Irv

[Pobboravsky]

I recommend 100% cotton velvet.  Google: https://www.google.com/search?q=cotton+velvet+fabric&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a     I believe I purchased white cotton velvet from DenverFabrics.

 

 

[Pobboravsky]

This relates to the amount of mercury needed to develop daguerreotypes.  It comes from Samuel Humphrey’s 1858 American Handbook of the Daguerreotype, pages 41-43.

“There are numerous opinions among operators in regard to the quanitity of mercury necessary for a bath. As regards this, I need only say, similar results occur when two pounds or two ounces are used, but the quantity generally employed is about a quarter of a pound. I am of the opinion that one ounce will answer as well as a larger quantity. I know of no better proof in favor of a small quantity than that presented  in the following incident. Several years since, an operator (Mr. Senter of Auburn N.Y.) of my acquaintance , was requested  to go several miles to take a Daguerreotype portrait of a deceased person.  He packed up his apparatus and proceeded over a rough road for some distance to the house where he was to take the portrait, and arranging his apparatus with all the expedition which the occasion required, after having everything usual order (as was supposed) ,  he proceeded and took some ten or twelve very superior impressions.  They were fine, clear and well developed.  After taking the number ordered, he proceeded to repack his apparatus, and to his surprise, when he took up the bottle he carried the mercury in, he found it still filled, and none in the bath, except only such particles as had adhered to the sides, after dusting and and being jolted for several miles over the rough road. From this it will be seen that a very little mercury will suffice to develop fine proofs.  I saw some of the impressions referred to above, and they were certainly well developed, and very superior specimens of our art”

 

 

 

 

 

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[Pobboravsky]

Thanks, John,

Interesting — the Dog-bone effect is new to me.  That is excellent information.  The plater’s tape must have super adhesion to stay attached during electro cleaning.

As always, you provide the daguerreian community with solid information.  To have a professional chemist who is a skilled daguerreotypist is such a big plus to the cdags community.  You always have been generous in answering questions.  Kudos to you.

 

Irv

[Pobboravsky]

Thanks, John,

Does Reliable test thickness destructively (i.e. by pinholing the plate) if you do not ask them not to do it?

What useful questions did I forget to ask?  Silly me.

Thanks for your help,

Irv

[Pobboravsky]

Hi John,

What is the largest plate size that Reliable Plating has done for you? Do you usually get 1/2 mil or thicker?   Does plating surface quality vary from one time to the next?

Your whole-plate daguerreotype — Tunnel View, Yosemite Park — is spectacular!  Clouds in a blue sky – glorious.  Congratulations.

Irv

[Pobboravsky]

Hi Daniel,

LOVELY!

Irv

[Pobboravsky]

Hi Greg,

Your argument for re-using the plates was so persuasive that I was ready to offer to swap new plates for your old ones. Just like the story of Aladdin’s Lamp – New lamps for old.

I apologize for even thinking you were serious. Please assume that I was/am mentally affected by sniffing too much mercury.

Irv

[Pobboravsky]

Hi Greg,

None of my business but — please consider tarnish removal first — you can always polish them if the images are hopeless. They may have important historical value.

I shouldn’t be speaking for Mike Robinson but he has a good tarnish removal method and perhaps you can discuss it with him and see what he thinks.

Best wishes,

Irv

[Pobboravsky]

Hi Daniel,

A very powerful portrait;congratulations.

Excellent suggestion to use high-wattage CFL bulbs at 6400 degrees Kelvin.

Irv

[Pobboravsky]

Hi Javi,

Scorn, schmorn – Munch’s painting go for big bucks. You should be celebrating.

The gilding of the second image looks good.

Remarkably good results for the first two tries.

Cheers, indeed,

Irv

[Pobboravsky]

Some of the 19th century daguerreian literature mentions putting out the flame of the alcohol lamp once the mercury reaches the aim temperature. I have no experience doing that. However, continue to do that; you don’t want to change in mid stream. Mike Robinson jokes that if you get good results while wearing green socks, wear them every time you make daguerreotypes.

The time-temperature values I gave assume that the thermometer is measuring the temp. of the mercury itself.

Good luck,

Irv

In my experience wearing brown socks always ends in failure.

[Pobboravsky]

Hi Daniel and Alan,

The proper dev’g time-temperature depends to some extent upon the design of the mercurizer. Early on, when I was working with quarter-plates I successfully dev’d at 90 deg. C for 75 seconds without frosting in the shadows.

In 1989, when Grant Romer and I made d-types in Paris we developed 5×7-inch plates for 6 or 7 minutes at 80 deg. C. This was done with a mercurizer of a different design.

However, either one of the above two Time-Temps. is a good starting point for your dev’g box, Daniel.

For the benefit of those starting out it would be interesting to list the good time-temp used by workers.

Good luck,

Irv

[Pobboravsky]

1) 5×7 inch

2) No

3) No

4) No

[Pobboravsky]

Hi Li,

My plates are 0.5mm thick. Mike Robinson’s clad plates are also 0.5mm.

Good luck,

Irv

[Pobboravsky]

Hi Li,

Plate extends beyond the platform about 3mm on all four sides. (Platform is smaller than the plate.)

Irv

[Pobboravsky]

I use 4 pieces (about 2cm each) of double-sided adhesive tape. For good adhesion, the back of the plate and the platform surface must be clean; otherwise the plate will not stick.

For cleaning use isopropyl alcohol and a small piece of paper towel. In the U.S. it is also called rubbing alcohol and is sold in drug stores. Another name is isopropynol.

Too much double-sided tape will make it very difficult to remove the plate; thin plates (0.5 mm) can be bent when trying to remove them. Avoid bending plates.

Good luck,

Irv

[Pobboravsky]

Hi Li,

Making daguerreotypes, especially when just starting, is very frustrating wherever you live. You are working very hard and you are making progress.

Your last daguerreotype has fewer scratches. However my guess is that you need to further improve the surface quality of the plate.

You will see the most improvement by doing a better job of polishing.

If this image was not gilded it will be easier to polish off the image and then work at removing the remaining scratches. Good luck. Do not gild until you have mastered the polishing step. Good luck.

Irv

[Pobboravsky]

Hi Li,

Your sensitizing, exposure, development and gilding are quite good now. I congratulate you. To avoid defects in the image, the surface quality of the copper must first be improved.

Carefully examine the surface of the copper (or brass) before silver plating. If the copper has deep scratches or other surface imperfections – the plated silver will also have the identical surface imperfections. Start with copper that has the best surface quality. Then polish the copper to remove the major scratches and imperfections. If possible have the plating shop polish the copper before silver plating.

Please describe: (1) the surface quality of the copper you are using, and (2) the polishing method used to remove the imperfections. Please provide a scan of the copper surface after polishing.

A copper surface without deep surface imperfections will produce a better electroplated silver surface that will be far easier to polish. This is true whether you do the electroplating or you have the silver plating done by a plating shop.

Good Luck

Irv

[Pobboravsky]

Have a few plates silver plated by a different electroplater. Polish the copper or brass before giving them to the electroplater. Good luck.

[Pobboravsky]

I believe you are gilding too long if the gilding solution boils. You may need to modify the gilding time-temperature for your conditions but I stop gilding when the solution reaches 60 degrees Celsius. I pour distilled water into my gilding tray (which contains the plate + gilding solution) to stop the gilding process. I use an infrared thermometer to measure the temperature of the gilding solution; it does not require putting the thermometer into the solution — you can measure the temperature by holding the infrared thermometer about 8 centimeters above the gilding solution. My infrared thermometer was made in China.

My congratulations on your progress and good luck.

[Pobboravsky]

You are making progress. I don’t know what changes you have made aside from increasing the exposure to 35 min. Please include f/# of lens and EV (exposure value). Also dev’g time. Please describe polishing steps.

Iodizing to a yellow with a reddish tinge may provide a bit more sensitivity.

Increasing the Becq-dev’g time will help.

Guessing that 35 min exp should have given a stronger image but not knowing what changes you made makes my guessing harder.

Good luck,

Irv

[Pobboravsky]

Thanks for the info.

A. f/8 does not let much light through. I would open the lens to its widest aperture. [f/5.6 doubles the amount of light getting to the plate; f/4.5 triples it.] Use the fastest lens available.

B. Move the lights closer to the subject, if possible.

C. A very rough exposure estimate for EV=10.6, @ f/5.6 is 30 minutes. Moving the lights closer would increase the EV (light intensity) and shorten the exposure time.

D. If the subject has a bright white it will appear first during Becq-dev’ment. I forgot to ask the color of the filter used for Becq-D??

Good luck,

Irv

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