Mercury Vapor

[Dwayne Martin]

Anyone out there using A Mercury Vapor plate burner (or bulb) for gum printing?

Thanks,
Dwayne

 

[Bill Burk]

I think mercury vapor are orange “non-actinic” light. That won’t do any good.

There are fluorescent bulbs, which are technically mercury vapor. There are BL bulbs that look like regular long glass fluorescents and they put out substantial UV but without the purple glass… because they’re not trying to withhold visible light.
You will need a bank of maybe six or eight of them and you need to check them occasionslly for consistent UV output.

Are you interested if anyone uses carbon arc or pulsed xenon.

 

[Dwayne Martin]

I think mercury vapor are orange “non-actinic” light. That won’t do any good.

There are fluorescent bulbs, which are technically mercury vapor. There are BL bulbs that look like regular long glass fluorescents and they put out substantial UV but without the purple glass… because they’re not trying to withhold visible light.
You will need a bank of maybe six or eight of them and you need to check them occasionslly for consistent UV output.

Are you interested if anyone uses carbon arc or pulsed xenon.

No just MV because that's what I have.

I actually have a Nuarc MV plate burner that I use for gum printing, I'm just trying to dial in my exposure times. It's my understanding that Mercury Vapor is considered 2nd best only to Metal Halide for gum. Bob Carnie actually uses a Nuarc Metal Halide Plate Burner for his gum prints. I'm curious if 1 unit of light is equivalent on either machine.

Thanks,
D

 

[Bill Burk]

Have you used stouffer step wedges?

 

[Dwayne Martin]

Have you used stouffer step wedges?

I haven't even though I have one. I've just been testing different times. I'll try the step wedge next...

 

[Bill Burk]

Step wedges show you where the exposure is correct, and you only need to count how many steps you are from where you want to be.

Say you want a solid step 3, and you got a solid step 5… You cut the exposure in half.

 

[Dwayne Martin]

Yeah you’re totally right about that. I’m going to place the wedge on a print next to the negative and compare the two. I’m about a good month into trying to learn gum printing and it’s pretty tricky to get right, at-least for me. All sorts of variables including humidity. I’m also experimenting with different sizing techniques like pva glue and gelatin. I made 4 test prints last night sized and unsized with 3 different papers. The funny thing is the best of the bunch by far was the cheapest paper and no sizing treatment, go figure….

 

[mshchem]

Good luck with your project. What little I know about mercury lamps is that certain configurations do indeed put out UV.

 

[Anon Ymous]

I think mercury vapor are orange “non-actinic” light. That won’t do any good.

These are the low pressure sodium vapour lamps. IIRC, mercury ones do emit UV. Mercury rectifiers for instance have a characteristic glow.

 

[Bill Burk]

These are the low pressure sodium vapour lamps. IIRC, mercury ones do emit UV. Mercury rectifiers for instance have a characteristic glow.

Yup I was wrong