Do you make dags in raining days?90%moisture content in the air

[newone2010]

Hi all,

These days,it’s always rainy in my town.I found it always failed in making dags.I think it was beacause of the high percent moisture content.Today,when I polish my plates,I use a hair dryer to make the temprature of the air around the polishing stand raise up.I thought it was maybe helpful to reduce the moisture,but I failed again.

In the rainy days,the last image always have much more black spots and lack in contrast than in sunny days.Does it caused by the moisture?When you know the moisture content in the air is too high,do you give up making dags?

Looking forward for your reply,

Li

[photolytic]

Li, you are right but don’t give up. High moisture content in the air is bad for Dags but it may also be high even when it is not raining. It is a good idea to get a humidity gage and record the humidity along with your other fuming data for each plate. Plates fumed with less iodine and bromine seem to be more moisture resistant.

Silver iodide is not hygroscopic but it is sometimes used to “seed” clouds to produce rain. The crystalline structure of silver iodide is similar to that of ice so it causes condensation of water in clouds which are supersaturated with moisture.

Heating the plate before fuming is also a good idea.

To prevent moisture damage, seal the freshly fumed plate in a plastic bag with silica gel or dry rite (sodium sulfate). After you expose the plate, put it back in the plastic bag until you are ready to develop it. If you expose the plate outside the house where it may be warmer,

Allow the plate to warm up to the outside temperature before you open the bag so the moisture in the hot humid air will not condense on the cooler plate.

As for the black spots, they may be caused by poor polishing which gets worse in high humidity.

During the polishing step the heat from the friction between the buff and the plate should be enough to heat up the plate. Charlie Schreiner recommends heating the plate during high speed buffing with wax rouge sticks to prevent polish build up on the plate.

If the plate is not heating up you may need to apply more polishing pressure

[newone2010]

John?thank you for your quick reply.Today?I tried again.It’s a cloudy day and about 80% relative humidity?Yesterday is 90%-95%?I polish my plates terrace?not in room?So I think high humidity is bad for plate polishing.If I polish my plates in the room,I think it will be better.

Today,my dags have much more less black spots and the contrast is better! 😆

It always rain these days.I think I need some rest now.

Thank you!

[Mike Robinson]

Li,

In addition to John’s excellent advice above, I’ll add a few comments.

Making Daguerreotypes on a rainy day is quite doable, providing you prevent moisture from condensing on plate.

I made this image at Lacock during a steady rain, while trying to hold an umbrella, focus, and insert the plate. Would have been nice to have an assistant.

I tend to seek the advice of the 19th century operators for problem solving. Usually the solutions are simple and elegant. For several years I have used a buff heater. This serves the dual purpose of keeping the buffs dry and warming up the plate before sensitizing. Even with relatively high humidity, if the plate is warmer than the atmosphere you shouldn’t have a problem. The next area of concern is after exposure. If the plate has cooled down because you are working outside in cold weather, simply holding a plate by the edges can cause a flash of moisture condensation locally and erase the latent image. The half-plate daguerreotype by John Plumb, owned by Matt Isenburg, shown here has a dark circular void on the left edge where Plumb handled the plate. It was a cold day when Plumb made the images. A vacuum Pick-up stick is excellent for handling the plate. Finally, if the plate is cool and your mercury bath quite hot and contains moisture, there is a risk that moisture will condense on the plate surface preventing development. Baron Gros would inject a few drops of ether into his mercury pot just before developing a plate. I understand that ether is a good desiccant. Its also quite flammable! Occasionally I’ve used ether when I’m developing in adverse weather in my mobile fume hood, but generally I prefer not to use it.

 

Mike

 

 

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[newone2010]

thank you?Mike?

I find other reasons which left black spots on the plate.I use a hand air-blowing ball to tyr to blow away the dust which may stay on the plates before each fuming time(just before I put the plates into the fuming box).I found this method can make spots on the plates.I think that may beacause of the dirty dust in the ball.When do you use air-blowing ball?each time fuming or just before the first fuming I? Before mercury developing,Do you use it too to try to blow off any dust which left on the plates in the exposure time?

Thank you,

Li

[photolytic]

Blowing the plate with the air dryer before fuming should be done on the back of the plate. Most Daguerreotypists use a large rubber bulb to blow particles off the front of the plate. However if you turn your plate upside down during the last hand buff there is less chance of leaving particles on front of the plate. Warming the buff immediately before use with an air dryer also helps. Blowing the plate after exposure but before mercury can be very problematic. If the air contains any moisture the image may be spotted.

Most sheet film photographers vacuumed the inside of their holders before inserting the film to eliminate dust spots. This is also a good idea for Daguerreotypists since the back of a polished Dag plate frequently contains traces of polishing powder which rubs off on the holder. Rubbing the back of the plate with a soft dry tissue will remove most of this residue but not all. Rob McElroy also air blows the holder slides before putting them back in the holder after shooting his Dags.

Since I always develop my plates in a vacuum over cold mercury, I keep a layer of silica gel in the bottom of my mercury chamber underneath the mercury dish to minimize the moisture content.

[dagist]

Li,

Dust is the daguerreotypist’s nemesis, as any one of us here will attest.

Each time my daguerreotype plate is introduced to a new step of the process, I blow off the dust. And I mean every time. Between polishing and all buffing steps; prior to and between fuming steps; prior to inserting the plate in the plate holder; and prior to putting it over the mercury. I also blow out my plate holder prior to inserting the plate, and as John mentioned, I blow off the dark slide, both before I insert the plate holder in the camera and also before I re-insert the dark slide after the exposure. This assures me (most of the time) that no airborne particles will have an effect on my image at any stage of the process.

Dust can also land on your plate from inside the camera too, during your exposure. So make sure and keep the inside of your camera dust free.

Something else to consider, is getting rid of the rubber air bulb. Many daguerreotypists use them, and “think” they are removing all the dust on their plates, but they rarely are. Those air bulbs do not put out enough air pressure in a small enough area to blow off the very tiny dust particles. They do a fine job with some big particles that are easily visible, but many of the microscopic particles still remain on the plate. Also, those air bulbs aren’t very accurate with the direction of their airstream because the tip of the bulb tends to flex (pivot) when you squeeze it hard to get full pressure.

Other daguerreotypists may disagree with me on this, but do not be afraid to use compressed air that comes in a can. That is the only thing I use for blowing dust off my plates, and it works phenomenally, providing a strong blast of concentrated air right where you need it. Always use the thin plastic nozzle that comes with the can of air. If you keep the can level and apply only modest pressure on the can’s trigger, you can get a forceful blast that goes right where you aim it. Hold the plate still (perpendicular to the ground), and gently move the can of air back-and-forth across the plate.

If you don’t respect your can of air, you can easily send some of the propellent from the can onto your plate, which will leave a mark. Just develop a technique of gentle trigger pressure and respect, and you will greatly reduce the effects of atmospheric dust on your plates.

The suggestion from others about heating your plate prior to fuming is very helpful for getting an evenly iodized surface. I use a hair dryer and it works great. It is the same hairdryer I use to dry my plates after they are washed. When using the hairdryer to warm the plate prior to iodizing, only heat the back of the plate, do not heat the front. And, after heating it, blow off the front of the plate one more time with your canned air before exposing it to the iodine fumes.

As Mike said, you can make d’types on rainy days. I’ve made several nice rainy day images but your success-percentage diminishes because of the sometimes unpredictable nature of the humidity. It does help to slightly warm the plate before putting it over the mercury, especially if the plate is a little chilly from being outside, but you must be careful, because you don’t want to cause any condensation to form which will adversely affect the image. Again, only heat the back of the plate, and blow off the dust on the front just before you place the plate over the mercury.

Good Luck,

Rob McElroy

Buffalo, NY

[newone2010]

:PThank you all for quick reply.

As all of you mentioned,Blowing off the dusts( rubber bulb or a air can)is helpful to remove the dusts.I did this before(use a rubber bulb which has a presure 30Kkp,I think it is the most powful normal rubber bulb),each time fuming I and Br,sometimes before mecury develop.

Now,I found this can left more spots on the plates,I think it maybe beacuse of the hnmidity in the air and some dusts remain in the ball.If I try to blow off the dusts before mercury develop,it will left more silver-white shiny circle spots which have black very tiny dots in the middle of the spots.(i think you know what I mean,some of your dags have the same problems).

In my town,it is very moist most time of the year.I think maybe I can not use a rubber bulb any more.If I don’t use it,I get better results.

Rob suggested using a can of air.I will try it!I think the air from the can must be very clean and has much more less moisture.I saw someone using it,the maintenance engineers of watchs and notebook computers.

By the way,I made 4 good dags these days,but all failed in the final step: Gilding.

I use a alcohol lamp to heat the back of the plates before,now I use a can of butane.It raise up the temprature rapidly and I can not control it now.I think I need more practises.

So much must to be learned during try to became a good D’typist.Thank you for all your patience since I asked questions again,and again,and again….. 😛

 

Good luck for everyone of you,

Li

 

[photolytic]

Hi Li

Using butane is ok but you need to hold the flame further away from the Dag. Heat more slowly.

Use strong lighting and watch for the first signs of steam above the plate then stop heating.

Use an infrared thermometer to check the temp at various points on the plate and don’t let the temp get above 60C.

Good luck, John

[newone2010]

Thank you?John.I bought an infrared thermometer as you mentioned yesterday.I will try it later.

[newone2010]

failed in gilding again. :cry:I am so dispirited.I bought a epson 4990 from ebay.It will arrive in 5 days.I will show you the gilding-failed dags.

[newone2010]

finally,I got my epson scaner.please see the attached image.The corner has a gold shiny color.It always appear during gilding.just like gold cover the corner of the plates.what did I do wrong?some plates have this problems,some not.

 

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