Emulsion Curing

1013 Views 4 Replies 4 Participants Last post by Rdevine16, Mar 17, 2018

Rdevine16

Discussion Starter · Feb 23, 2018

Hi forum. I am currently using RPX Dual core emulsion on a 156 mesh screen. After 24 hrs of drying I place the transparency film on the back of the screen with a foam pad under the screen creating a positive contact with the image and the glass sheet on the top layer. I have a 500 watt work light (glass removed from light) that sits 12 in above the glass. The exposure is on for 20 minutes. When I was it out I notice that the emulsion has a slight slime feeling to it. I would think after 20 minutes I would at least be over exposed.

Just wondering if I’m missing something.

Save

1 - 5 of 5 Posts

PatWibble

· #2 · Feb 23, 2018

Rdevine16 said:
Hi forum. I am currently using RPX Dual core emulsion on a 156 mesh screen. After 24 hrs of drying I place the transparency film on the back of the screen with a foam pad under the screen creating a positive contact with the image and the glass sheet on the top layer. I have a 500 watt work light (glass removed from light) that sits 12 in above the glass. The exposure is on for 20 minutes. When I was it out I notice that the emulsion has a slight slime feeling to it. I would think after 20 minutes I would at least be over exposed.

Just wondering if I’m missing something.

Slime means it is under exposed (assuming that it was properly dry to start).

Check your bulb. Newer work lights tend to come with a bulb that only emits light at 2700 -2800k ( kelvin). These give off very little UV light. Search online for a bulb that emits light at 3200k, which is about as high as halogen bulbs go ( you might get lucky and find one at 3300 or 3400k). There will be much more UV light, meaning a better or faster exposure.

For the cost why not consider upgrading to a 1000w worklight?

Save

NoXid

· #3 · Feb 23, 2018

Do a step wedge test to determine proper time. Also, do not go thicker on the emulsion than needed, as it will not dry or expose right. How green is your glass sheet when looked at on edge? Low iron glass would block less UV than normal glass and not look as green.

Save

Ripcord

· #4 · Feb 24, 2018

Best advice for exposure is to hit it hard. Overexposure will generally result in fewer problems than underexposure. Of course if you go overboard you can make the screen impossible to rinse, but it takes a lot to go that far.

Save

Rdevine16

Discussion Starter · #5 · Mar 17, 2018

So I talked to the company I got the emulsion from and they said I might have a bad batch of emulsion. They sent me a new one and followed the same process as I did before and the print came out perfect.

Watch out for bad emulsion.

Save

1 - 5 of 5 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month