[nawagi]

T-

Changes in Bromine box strength arise from time, heat and exposure to the air. I find almost no change over an hour’s time, and no change over during a working day of 8 hours (or 8 plates at my snail-like pace). Significant changes occur from one week to the next, or if the box has a big temperature swing. I keep my boxes in my garage, which is hotter in the summer and colder in the winter. I must bring the boxes inside to stabilize at my darkroom temperature for 24 hours before I use them- but that constant temperature leads to consistency.

It becomes very challenging when sensitizing plates in the field as temperature can vary.

I am sympathetic to your frustration with having to do a test plate each time. I changed my attitude about tests a while ago. Yes they take time and materials that you would rather use for a beautiful dag – but that test is what
makes the dag beautiful. And one test in the morning is a small price to pay for a day of good plates – even two days if the weather holds.

NWG

[nawagi]

Renaissance Graphic Art Supply carries them in 2 styles: economy and polished.

NWG

[nawagi]

T-

As you have learned, Bromine time changes based on weather, temperature, the color shirt you’re wearing, etc. It is different every day.

I run a test plate at the beginning of every shooting day to determine my Bromine time. I use a set of vertical masks, each exposing 1/4 of my plate, after fuming Iodine to my standard color choice (rose-magenta). I fume the masks to Bromine for 2, 4, 8, and 16 seconds – then expose and develop my test plate. The best Bromine time for the image is easily selected off the test strips.

The test plate is also an excellent ‘rehearsal’ for multiple steps Dag creation requires, and to ensure all the supporting chemistry is behaving properly.

Selecting your Bromine time this way adjusts for all the variables you can’t control – including the strength of your Bromine. Your image of Brominated Silca gel is good – although my working color is lighter than yours.

Iodine times can be very reliable based on your eye and the plate color. Plate color does not work for Bromine – it is a timed reaction with minimal visual clues.

This past weekend, plates fumes to 1st rose-magenta needed 6 seconds of bromine time. Next weekend it will be different as the humidity has dropped considerably here.

NWG

[nawagi]

I mix liquid Bromine with silica gel. I try to get it bright yellow (“post-it” note yellow, if you have that product in your country). I’ve found that as the Bromine color heads into orange, it is too powerful.

I also heat my plates with a blow dryer before fuming to accelerate the chemical reactions.

NWG

[nawagi]

Marc-

First Iodine sensitizing to yellow with rose hints

Bromine must be tested in steps. I use a strip mask to fume to 3,6,9,12 seconds of Bromine.
I do not use color to determine my Bromine times.

Second Iodine (“healing” the plate from the white light used to check color) is around 1/4 the first Iodine time.

Recent shooting: 30 seconds 1st Iodine, 6 seconds on Bromine, 5 seconds 2nd Iodine = nice medium contrast plate

NWG

[nawagi]

PTFE sheets can be found on Amazon by searching for “Teflon sheet”. I cut the sheet to fit inside the mason jar lid and completely seal the rim of the jar. Also handy for sealing the lids of fuming boxes.

I store the Bromine-charged silica gel the same was as I store liquid bromine: inner 500ml brown glass bottle with PTFE lid and tape, outer mason jar with PTFE lied and tape, sealed metal paint can.

I don’t need to stabilize the brown glass bottle inside the mason jar- it’s a tight fit. When I place the mason jar inside the paint can, I center it in the can and then pour about 4″ of vermiculite between the can and the jar to keep everything stable. I learned this from a chemical shipper. You can find clean vermiculite at any garden center.

Andy- I appreciate your kind words. I hope I can contribute even a portion of what you and John have to support the working Dag community. I’ve thought about posting videos showing some my safety procedures, but hesitate to “let the genie out of the bottle” and have someone less cautious that I quickly attempt the process and injure themselves (and then sue me…). Like John, I have extensive lab experience dealing with some very dangerous compounds. Respect, caution, personal protection and training all work together to make a safe and beautiful image. And I still have all my teeth…

NWG

[nawagi]

A recent sensitizing time:

I Box: 300 g. Iodine in glass baking dish with a single layer of polyester batting (upholstery padding) to diffuse fumes. I use a ground glass cover on both fuming boxes.

B Box: Liquid Bromine in silica gel with single layer of polyester batting as above. Gel is light yellow in color.

(Can provide Bromine prep details later if you wish)

Air Temp: 22 deg C
RH: 60%

First I: 30 seconds- light rose (just after first yellow); plate rotated 180 degrees after 15 seconds
Bromine: 6 seconds – determined using “strip” mask on test plate at 2,4,8,16 seconds
Second (Healing) I – 5 seconds

Exposure in bright sun (EV=16) at f11 was 8 seconds

I use a hand-squeezed air bulb for dusting plates- I found “canned air” created marks, and I know my air compressor air has oil and dust in it.

NWG

[nawagi]

Craig-

I’ve found that using microfiber ultrasuede (Suedine) on the final buffs works well. Like Jason, I tried using chamois for a season and abandoned it due to repeated fails. You may want to check out this site:

https://tallerdaguerrotipo.wordpress.com

While he’s just working on Beq’s, his polishing technique produces terrific plates.

[nawagi]

See if this test plate helps you. The image was in bright sun, EV of 16.
I-30, Br at :02, :04, :06, :08; I-Heal-10 – exposure info at the bottom.

I think your image is overexposed and over bromined.

NWG

Attachments:

You must be logged in to view attached files.

[nawagi]

Where can I read about the MiM Dag process? Your table and illustrations are interesting, but there is no process description in the files.

NWG

[nawagi]

T-

Three suggestions for you:

1) 3M 9500 PC – double stick tape for metal to plastic adhesion
2) 3M 9495LE – heavy duty tape for sticking to powder-coated surfaces, slick plastics
3) “Hook & Loop” (Velcro) on plate and mount- allows for re-positioning, but leaves air space between plate and mount

I use 9500 PC for attaching plates to my acrylic hand buffing block. I use hook & loop for mounting my tintypes to stretchers for exhibition.

Nate

[nawagi]

B-

You have two terrific ‘scientific’ instruments: your eyes. Bromine fuming changes the surface color of your plate over time (just like I). Training your eye to color changes will allow you to adjust for different strengths of fumes in each box. The Br step test I mentioned is an aide in training your eye: look at the plate after each step and you will see this; memorize the color and you will use it.

Be wary of “rote” – just because 30:06:10 works on Tuesday does not mean it will work on Wednesday. But straw:first magenta:10 on Tuesday almost always works on Wednesday. John has a distinct advantage over me- 1) he’s a genius and 2) he has a true scientific lab. He also has 10 times as much “time in the saddle”. Not to put too fine a point on it, but my 100th plate was a heck of a lot better than my 10th (can’t wait for number 1000! eta: 2020)

Humidity is very problematic in dags- for buffing and fuming especially. I run a dehumidifier in my lab all summer to keep the RH at around 50 – 55%. Even then, a walk outside into the very humid Connecticut summer air can wreak havoc on a plate. But I always think about our 19th century operators- they had slaked lime; a different solution tot he same problem.

BTW,I started with Br and Lime but changed over to Br and silica gel- less of a mess and easier to get a consistent color without so much “up close and personal” face time over the toxic fumes.

NWG

[nawagi]

Are you making test strips?

Hg pots require very little mercury – about the size of a 1 Euro coin is plenty.
I cook at 80C for 4 minutes.

Bromine looks pretty strong – and you Br times seem very long.

If I were over your shoulder, I would suggest the following:
1st fume to 1st yellow
Br in 4 strips: 10, 20, 40, 80 seconds
2nd fume 30% of first fume time.
Expose a bright scene (EV 15 at ISO 100) at f 8 for 4 strips: 8, 15, 30, 60 seconds.
Hg Cook at 80c for 4 minutes

Evaluate the plate for the best white without solarization (determines bromine time) and best shadow detail (determines exposure time).

NWG

[nawagi]

Keep careful notes on your work – every aspect from buffing through sensitizing. Note what succeeds and what fails.

Test Test Test – both fuming and exposure tests will teach you a great deal. A typical NWG test plate has a set of four different fuming (Br) times along one axis and four different exposure times on the perpendicular axis – that’s 16 choices. Pick the best fuming time and exposure combination as a starting point, then expose 3 plates: one a stop over, one even, one a stop under- one of these plates will be beautiful, but you earned it.

Be a consistent operator- There are so many variables in the process, the only way to control them is being systematic. For example, buff your plates the same way every time- same rouge, same stroke count, as close to same environment (temp, RH) as possible. Ditto with fuming and guilding. And when you decide to alter the process, alter one ONE thing at a time. Every aspect of a Dag is connected to every other aspect. Frantically changing a bunch of work flows willy nilly will produce poor results every time, or a “lucky” plate that is unrepeatable.

Read Read Read – A nice shiny plate ready to work costs $50. A hour reading on the inet = free. This site has terrific information throughout all its pages. The Dag. Society also has very strong resources for the contemporary worker through their inexpensive reprints. Get them all.

Get a mentor. I have been very fortunate to meet and work with some terrific Dag artists. They all made me a better operator by generously sharing their successes and failures. They (and I) pay this forward through a site like this.

NWG

[nawagi]

Congratulations… you have my deepest sympathy.

NWG

[nawagi]

Bing-

The best advice I received from Mike, John, and others was to learn the colors of fuming. Chemical concentrations and ambient temperatures change. But the color spectrum of fumed silver is a constant, thought the progression of colors speeds up with heat and, thus, more chemical vapors.

I suggest you run several ‘sacrificial’ plates and watch the color progression develop through three spectral cycles. It will give you “eye memory” for the fuming color progression, and help when discussing fuming with truly skilled operators like Mike and John.

NWG

[nawagi]

I protect the image with a thin piece of cover glass. Surplus Shed.com has terrific Schott glass in very thin 12″ square sheets. They also make for a great ambrotype.

NWG

[nawagi]

Blake-

I dry my plates this way:

Final rinse in a tray of distilled water. Have a dedicated blow dryer plugged in and ready (Dedicated= only used for Dags, tape a cheapo painters dust mask over the dryer’s air inlet to really cut down on dust).

Fire up the blow dryer at top heat and air speed. Pull your plate from the tray and lean it 75 degrees away from you, short axis parallel to the floor.

Starting at one corner, aim the dryer about 1 – 2 inches over the plate’s surface (careful!) and sweep it down with a back and forth motion. You will see the water run away from the stream of hot air, the surface drying as it recedes.

“Push” that drying line right down to the bottom of the plate. There will be a line of water there (what you drove down) so linger with the heat until it is all evaporated. Voila – a stain-free dry plate ready to case.

If you miss a spot and get stains, immediately re-submerge the plate in the distilled water and repeat the process. I’ve saved many plates this way while getting my technique down.

[nawagi]

Blake-

I lean my Beq. developing holder against a rock so that air can flow behind it. I also use a small portable fam to keep the air moving if its a warm day.

Can you share the name of your plater with the forum? We’re always looking for new resources, and your description of the quality of his plating job sounds worth checking out.

NWG

[nawagi]

Blake –

A few thoughts on my experience with Beqs:

Plating: I initially used a local plater who was very cost effective: $10 for a 5×7. He’s a military contractor and fit my stuff into his job runs. But…his plating results were heavily “frosted” and took a great deal of polishing time to be usable. I then tried the platers listed on this site (Theta, Theiss, Zapfe). They charge 3 to 4 times as much – but the quality of the plating was terrific. Zapfe in Seattle was the most expensive but produced plates so good you could almost use them out-of-the-box. I found Theta Plate a good compromise for price and quality. If your local plater will work with you, try different volatages and times in the plating bath – slow and steady wins the race here.

Buffing: Yes it really is ALL about the buff and polish. There’s a lot of good work flows on this site on plate prep- pick one you like and stick to it. When you introduce many variables in the buff/polish, you’ll never know what you did right or wrong. I could tell you what works for me, here in Connecticut- and I know what Jerry does in NYC, or Mike in Toronto, or Jason out west are different- but we all get good results. If I was to give you one piece of buff/polish advice: double the amount of time you think you need by hand, and groom your buffs regularly.

Iodine: Chemsavers (on the web) will sell to individuals. ACS grade is fine. I use 100 grams cut with 100 grams of silica gel. Lay a thin piece of polyester batting on top of the crystals to even out the flow of iodine fumes. I charge my box 48 hours before shooting and keep it in a 70 degree constant temperature room for fuming. I store the crystals in a brown glass bottle with ptfe lid, Teflon liner and two wraps of “gas pipe” Teflon tape (not the plumbers grade) around the theads. I keep my fuming boxes and chemistry in my garage locked up. NEVER heat up iodine crystals.

Exposures: While Beqs are mostly UV sensitive, a light meter that measures EV is helpful to dial in exposures. But remember that UV is a function of the sun, so time of year and time of day make a big difference. Think of getting a sunburn: 10am – 2pm is the best time of day, June – August the best times of year. But UV reflects strongly off water or snow, so if that’s in your image you’ll get a shorter exposure. I shoot a test plate on a given shooting day to dial in the time, typically 1 or 2 minute steps at f5.6 or 8 depending on conditions.

Development: I use amberlith in bright sunlight for 1 – 2 hours. You’ll see an image start to appear in the first 15 minutes, and with experience you can gauge your exposure using this brief development period. Preventing foggy development rests on 2 things: keep the plate cool (That 500 watt halogen worklite will fog the heck out of a plate unless you keep a fan on it) and make sure your plate is sealed into its amberlith mask on all 4 sides with lightproof tape.

Gilding: Jason is correct. Guilding Beq’s is a waste of gold chloride. When and if you go into Hg dags, then guilding comes into play (and really improves plates).

Notes: Okay, call me a frustrated scientist. I take meticulous notes on everything. It has helped me troubleshoot faster and better, and helped me get much better exposures under a variety of conditions

I also work in wetplate (13 years) – started Dags 2 years ago and love ’em. Good luck, and it truly is worth the effort!

Nate Gibbons

[nawagi]

M-

I prepare my engraver’s polished 18 ga. plates in this manner:

I size my plates 1/4″ over the final image size. This allows an area to drill holes for the plater’s wires that I then trim off when they come back – no holes on my shooting plates.

I drill 1/32″ holes at two corners before buffing and use a file to smooth off any burrs at the holes

Remove the plastic covering and mount the plate on a solid surface. I use double sided “carpet” tape.

Get a random orbital sander and make up a pad of thick felt or wool – cheap, worn out wool blankets work well

Mix a slurry of flour-grade pumice and canola oil (any light oil will work – food oils are easier to clean up)

Place a 1/2 dollar sized puddle of this “polish” on the shiny side of the plate. Use the orbital sander with pad to buff the surface in even strokes: I buff 60 seconds left to right, 60 seconds top to bottom, 60 seconds left to right.

The plate should have an even matte finish when the polishing is complete.

Wash and dry the plate carefully. Wrap it in a clean plastic sandwich bag for transport to the plater.

Mistakes I’ve Made:

Wrapping the plate in paper towels and securing the towels with rubber bands – the rubber bands reacted with something and bled through to the copper. After plating these lines came through in images!

Buffed the wrong side of the plate (it looked shiny to me!) – I now label back of all my plates.

Used water instead of oil in the polish slurry. Some operators like water- did not work well for me.

[nawagi]

Thanks John – I appreciate the help.

NWG

[Author]

Posts