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studiocarter
10-11-2009, 11:55 AM
There is a video to watch on line that shows a 20 x 24 inch plate being poured. It is on the John Coffer web site. http://www.johncoffer.com/
On the left side it says "videos", go there and choose the longest one, ten minuets.
Now, this is a wet plate video, but it is a huge plate that is hand poured. I am into dry plates and have hand poured 4 x 5 inch plates and am sweating how to do 12 x 15 inch ones. I suppose that if the liquid emulsion is thin, warm, and spritzed with Everclear it'd cover a large surface in red light. Perhaps a piece of marble could be warmed and the glass set on it. If there was a gimble under it, it could be tipped this way and that and thus eliminate hot finger spots. John used his hands, but he used a metal plate. It didn't matter.
Has anyone here poured large plates for dry plate photography? How?

Kirk Keyes
10-11-2009, 05:14 PM
I've got some 12x20 in plates in the darkroom awaiting this. I've done 5x7 and 8x10 with varying degrees of success... I was actually going to try a glass rod for the big ones.

wildbillbugman
10-11-2009, 06:49 PM
Hello,
I wonder if a large heating pad, from the drug store, would work. You could tape it securely to the back of the glass plate. Then use those stick on temperature strips to measure the temperature of the plate, once it is stable. Then bring the emulsion to the same temperature and pour your hot little heart out. I have used this method for Gum/dichromate on glass. It works well for that purpose.
Bill

wildbillbugman
10-11-2009, 06:53 PM
P.S. For pouring plates without tipping, I dip my edges (the plate edges that is) into hot parafin. The emulsion is repelled by the wax.

studiocarter
10-11-2009, 07:06 PM
That could lead to thick emulsions if not carefully done.

Mike1234
10-11-2009, 07:12 PM
All this is beyond my abilities. I'll stick with film... until it's NLA... but by then I'll probably be NLA too. :)

Photo Engineer
10-11-2009, 07:18 PM
Big plates were usually made from huge sheets of glass that had the emulsion poured onto them from a cascade trough. The dried sheets were then cut up into the desired plate sizes.

PE

studiocarter
10-12-2009, 07:16 AM
Hey, these ideas are great and got me thinking more, along with am coffee...
Would the wax repell collodian? If so, they, ie wet plates, could be used in metal book form dry plate holders and the front edges wouldn't get messed up.
An old window frame could be used to hold onto glass while tipping and pouring; a hole, cork, and spout in a corner would let out excess material; waxed edges would keep it all clean. The frame would have to be the same size as the camera.
Well, why not make a window frame camera? Corners often get loose so it could be taken apart and grooves cut for a dark slide. Lots of windows are trashed around here when new ones are installed. I've used them for silk screen printing. Also, I've sand blasted glass in a stone shop as well as handled hydrofloric acid which eats glass to frost it, so that is possible to do as long as a shop is nearby making granite memorials. Bathtub refinishing companies also use that acid.
Glass could be silk screened and if warmed any texture would smooth out; that's a guess, screens can be huge, not as large as for a cascade trough but large enough to cut up glass after coating. Anyway, if large enough, texture would not matter from the diagonal viewing distance.

studiocarter
10-12-2009, 07:20 AM
Mike1234, if I thought like you, I'd-a bought or bid on that 12x20 camera that just sold on the bay for $811. It took film.

Photo Engineer
10-12-2009, 08:41 AM
Some sort of frame around the glass plate to hold it during the pour would be nice.

How about a takeoff on Sandy King's method. Lay the plate on a large metal surface and put magnetic strips down each side of the plate to hold it tight against the metal. Then pour.

The magnets can be custom cut to the size of your plate.

I have a set of custom coating blades for plates.

PE

dwross
10-12-2009, 09:46 AM
I use a system that works very well for me. http://www.thelightfarm.com/Map/DryPlate/PlatePrep/DryPlatePart4a.htm

I don't have the arm reach to coat the 12x20 inch plates I gave Kirk, but I have had great results as large as 11x14. I'm looking forward to seeing the mammoth plates when Kirk and Don (6'4"!) get them coated. As with all things art, there are enough great ways to accomplish a task everyone can find a method that works best for them. Coating should never be the roadblock to dry plate photography (or paper making).

Ron: Where are you selling your plate blades?

d

studiocarter
10-12-2009, 09:58 AM
What's that? Selling plate blades? Me! Me!
Magnets? Cool! Or I should say, variable temperatures:)

dw, can you make me a big glass coater yet for the 12x15?

Photo Engineer
10-12-2009, 10:29 AM
I have never placed the plate blades on sale. I have the demo blades shown at the workshops for film and for plates (two sizes) and that is all.

PE

Mike1234
10-12-2009, 10:30 AM
Mike1234, if I thought like you, I'd-a bought or bid on that 12x20 camera that just sold on the bay for $811. It took film.

I'd love to shoot 12x20 but I can no longer carry the weight/bulk of a system like that. I'm afraid 5x12 is my upper limit these days... and that's really pushing it.

My hat's off to you gents (and ladies if any making glass plates). I would probably mess up every single one I tired to make. Besides, carrying holders full of glass plates... it ain't gonna happen here pard's. I do hope to see plenty of glass plate image posts from you brave lads though!!

RobertP
10-12-2009, 10:40 AM
I've had great success pouring large wet plate collodion plates in 11x14- 12x15- and 12x20. John Coffer was the one who got me started in the process. What John does, and I find works very well, is thin your collodion with a 50/50 mix of alcohol and ether at about 10% of your volume of collodion. What happens with the larger plates is the ether is evaporating quickly and your collodion is starting to set up before you get your plate coated. Once you bring your plate up vertical onto your pour-off bottle rock it vigorously before you bring it back flat. Once your bring it back flat turn it and give the edge of the plate a little tap against the table the opposite way from the pour off corner. This helps eliminate those flow lines you see in some plates.

Photo Engineer
10-12-2009, 10:47 AM
I do not do wet plate collodion, but my understanding from those that do is that the methods of coating, while similar, are not exactly alike. I think that one must adjust to two different, but similar environments. It seems to me to be like stepping through a looking glass from the way I read it.

I would appreciate comments from those who have done both.

PE

dwross
10-12-2009, 11:25 AM
Studiocarter: re wells: Yes, indeedy. Let me know when you're ready to coat big.

Mike 1234: I hear you on the weight of glass! It doesn't seem to get any lighter with the passing years. Can't beat it for beauty and economy, though. Fortunately, there's an option. You can coat the same emulsions of a film base with no more difficulty than coating paper. The Photographers Formulary sells a product called Melenex, 7 mil estar film pre-coated with a substrate that holds onto the emulsion. And, handmade 'subbed' film is just around the corner. RE glass plate posts: Here's a few: http://www.thelightfarm.com/Map/Gallery/gallery.htm and http://thelightfarm.com/Map/DryPlate/Osterman/DryPlatePart4.htm.

Denise

Mike1234
10-12-2009, 12:01 PM
Thanks, Denise. I'll look into that option. :)

wildbillbugman
10-14-2009, 02:52 PM
[QUOTE=studiocarter;875879]Hey, these ideas are great and got me thinking more, along with am coffee...
Would the wax repell collodian? If so, they, ie wet plates, could be used in metal book form dry plate holders and the front edges wouldn't get messed up.

Hi,
I think that the ether/alcohol mixture in wet plate would,at least,soften the wax. But if you are willing to do a little trial and error, you could easily take a piece of clean glass and put drops of various varnishes on it. When the drops are dry, just pour on some wet plate colodiun mixture. See how the collodiun interacts with the dried varnish. A water bourn clear coating might work.
Bill

jnanian
10-14-2009, 03:55 PM
how did george eastman and alfred harman coat their plates ( originally ) ?
from what i have read, in the beginning they weren't very sophisticated, but it was consistent ...
did they elaborate tools, or were they just pouring and using glass rods ?
when i was coating, i free-poured my plates ... and sometimes i used a "sponge-brush"
(sorry if i am hijacking the thread)