[mamabloom]

I've switched emulsions to Amex Screen Sol QV Emulsion.
I sensitize it, let it stand over night (in dark) coat screens, let stand in dark overnight, expose and everythings great.

Store emulsion in dark (in a box in a box so it's defo dark) about 2-3 weeks use again and it won't work.

I do everything the same second time around and it's not working.

The screens won't wash out (like at all) , i can see the graphic outline but nothing washes out. It's like it's been exposed already.

My room , is under exactly the same conditions each time so why is it not working the second time? It's driving me mad.

It's not especially hot (im in UK), the room isn't pitch black as i cover up windows but it's the same for both.

I've exposed screen with other emulsion before and it's been ok.

I'm thinking maybe i need to keep emulsion in a fridge or bring into my house (it's in an outside garage) ?

How much light is needed to pre expose a screen and it not work?

Any help much appreciated.

 

[TLK]

It shouldn't 'go off' for 6-8 weeks after sensitising, if it's kept in the right conditions. We use the QT version without any problems but don't have it sitting around for that long to be fair. You could try storing it in the fridge or a cooler place. It has been warm lately.

It might not be the emulsion. Have you checked other things? Screen drying temperatures, ink density on positives, exposure times. Just a thought...

 

[TABOB]

It hasn't gone bad obviously... so it is something else.


Ensure no light is reflecting to the back of the screen when you are exposing it.



Reduce the exposure time and see what happens.



Keeping it in the fridge is something you should be doing by the way.

 

[mamabloom]

Thanks for your reply, i've just used another emulsion and it worked so i think the AMEX one is quite sensitive to temperature or something? It's just SO frustrating !

Really disappointed with the company i bought from as asked for advice and they didn't want to know, youve been far more helpful! Thank you.