Troubleshooting Dry Plate Tintypes

[drgoose]

OK, this is my second tintype using the Rockland Collodion Parlour Kit. The exposure I think is closer to what it should but there are a bunch of artifacts in the emulsiion that I would love to know 1) what to call them and 2) how do they occur.

a) Little black dots sprinkled throughout. They look like the emulsion disappeared from those spots. When originally coated and even after the fixing those spots were not there. They appeared as the plate dried.
b) Little wavy lines on the edge of the plate which when you examine the plate looks like the emulsion wrinkled.

All help greatly appreciated.

Joaquin

 

[removed account4]

maybe the black dots are popped air bubbles ?
maybe the black is the plate ... and the emulsion didn't "stick" ..
the wrinkling i believe is called "frilling" ( emulsion lift )
and it happens when the emulsion doesn't adhere completely
and stretches and dries again .. i think that is the name and what causes it ...

nice plate btw !
looks like you are having fun
- john

 

[drgoose]

Thanks John, this is pretty fun!!


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[Simon Howers]

Spreading the emulsion on the plates is a bit of a trick.
Typical faults are
1) the emulsion not sticking in places - it pulls back as it dries - leaving the backing showing, hence black areas
2) the emulsion is too thick. This crazes as it dries - typically into wavy lines with a matt finish.

You seem to have both!

Rockland plates are pretty good at adhesion, certainly far better than the plates I use, which are alloy sheet sprayed with black cellulose paint (auto touch up).
Possible solutions:
Wipe plates with iso-propyl alcohol before use
add a couple of drops of wetting agent to the emulsion before spreading

The emulsion will only spread thinly enough if sufficiently warm to flow easily across the plate.
It really does need to be pretty thinly spread - most people who are starting out make it too thick.
This is just 'practice makes perfect'.

Good luck!

Simon

 

[seanjmc]

he's off to a good start

looks like bubbles that popped...could have been dust/dirt got in emulsion when you were coating it. I always rinse off the plates first as often there is a 'bad' side or area, if the plate looks 'dry' right away, it's a bad spot that the emulsion may have trouble sticking to.....but that doesn't look like what's going on there....