[icex]

I just started screen printing a few weeks ago. Got the t-shirts pretty well down pat using plastisol inks. Got a order for 300 campaign signs, how much harder could it be from shirts?

WHAT a pain.. I got a brand new 8 bulb lightbox in (was using a 500w halogen), and tried burning the screen. Worked fine the very first time but forgot to mirror the image. Reclaim the screen and try again. Emulsion breaks apart. We try again, breaks apart again. Try again and same thing. Figure underexposure and up the time by a minute.

Try it again and it won't wash out. Overexposure? Who knows. By this time I'm ready to throw the damn thing. We try yet again, and half prints half don't. Figure up it's a off contact issue, take about 3 minutes to fix. Try again and the ink (CRP Ink) is dried in the screen.

Reclaim the screen yet again, ghost image appears. Try ghost remover/dehazer and it don't work. Coat and burn it again, emulsion washes out and runs down screen.. I figure screen is toast now.

I swear I don't understand is wrong. I never had this much problem with printing t-shirts.

Anyone do screen printing and have any clue on what the frig is wrong? Client is pissed because they wanted the signs Wednesday morning (just ordered Monday) and their still not done. I've ordered 4 more screens (their 230 mesh 23x31 by the way) but they won't be in until Monday.

The only thing that worked is my first screen I coated and let air dry. The other screens that have messed up I've used a fan to dry. Could this be the problem? Along with that sometimes I put the emulsion on to thick.. I don't understand how cause I'm using a scoop coater and apply firm pressure with it and go pretty quick applying it..

Help me before I put my head through a wall. It's already cost me a lot of money.

 

[PatWibble]

You need to use retarder with correx ink to slow down the drying. It dries by solvent evaporation not heat curing.
Thickness of emulsion isn't necessarily a problem as long as it is dried completely through. If still damp next to the mesh then it will wash out.
Fan heaters can be problematic- emulsion gets [email protected]@ked if it gets above 95 degrees. Gentle heat or air drying is best.
Have you degreased the screen? Must be done everytime, even when new. If you havent got degreaser then wipe the screen over with Metholated Spirit on a rag. No need to rinse, just let Meths evaporate.
How has the emulsion been stored? Could be that it is past its best. Needs to be stored in cool dry place. If it was a new tub then how was it delivered? Was the sensitiser in a light tight container? If not it could also be [email protected]@ked. Was it damp? Problem with emulsion is that most of the guys that supply it buy it in massive containers and divide it down. You are trusting them to store it and handle it correctly. Just because you have just bought it doesn't mean its fresh, particularly if you bought it from a smaller supplier.
Is your emulsion suitable for solvent inks?
Try again - leave plenty of time for the emulsion to dry. you need to work quickly and keep the ink moving. Make sure you have the space to dry the signs. Allow to dry between colours.
If it doesn't work then drink the Methalated Spirit - it will send you blind but at least you won't feel it when you put your head through the wall!
(I was just joking about drinking the Meths)
I make no apologies for the correct spelling.

 

[tpitman]

You should use a solvent-resistant emulsion. Buy a solvent ink press wash in addition to the retarder. Keep your stencil area flooded between print strokes. Get your work area set up with everything you'll need because once you start you have to keep printing. As soon as you finish, clean the ink out of the screen and wipe out thoroughly with the press wash, then take the screen to the sink and wash with your usual ink degradent and reclaim if you're finished with the screen. Buy one of those $30 3M respirators they sell in Home Depot and work in an area with good ventilation, unless you like that cheap high you get and envision a future as one of those guys who huff paint in a paper sack behind a dumpster.

 

[Omni]

Pat Wibble mentioned degreasing screens........And I think this may be the area of concern for you......Your first screen worked, but you mentioned other problems with subsequent screens after reclaiming your first screen.....If you did not degrease the screen thoroughly after reclaiming it, then there is a strong possibility that there is dried up reclaim residue on your screen....This could cause problems with your subsequent attempts to recoat, reburn, as the dried reclaim residue could mix with new emulsion and cause all kinds of problems with subsequent attempts at processing that same screen......Most emulsion haze with reclaim liquid that is left to dry on a screen will permanently lock in the fabric and destroy its' usability........or cause a variety of other emulsion problems.....I use Simple Green to degrease .........and be thorough, even on the frame where the mesh is attached.........