[Stitchlord]

Hello!


I am new to screen printing, I've been dabbling and slowly acquiring equipment. I am trying to do a large scale print on some fabric but I'm having some trouble exposing the screen. I did a step test and got decent results, enough to figure out my time at 12 minutes with a 500 w halogen bulb, but I got a wavy sort of moire texture throughout the print. I tried a second time for the actual final print, but had issues with my screen getting ripped by the scoop coater, so I think my emulsion went on too heavy and wouldn't wash out at all. Not only did my transparency stick to my screen a bit, leaving a film on the back of it, I again noticed that wavy texture after the lamp had heated up after about 6 minutes. I tried putting weight on the sides of the screen to no avail.

Does anyone have any tips? Is it getting too hot? Do I not have enough foam in the back? Do I need to find a better way to weight this down?



Here's a picture of what's going on...
http://rebelshaven.com/images/Pers/screen.jpg


Thanks for your time!
~Vera

 

[NoXid]

Not sure I can say exactly what is going on, but I can offer a few tips.

If the film/ink is sticking to the emulsion, the emulsion is not dry (maybe the film, too). If the emulsion is too thick, it is unlikely to dry well. But even a proper coat can't dry if the humidity is too high. You can get a humidistat for around $10 at Home Depot. If you don't have a place under 50%, you may need heat or dehumidifier or both. I use both.

Yes, you should have a block of foam under the mesh, with a black piece of paper on top of the foam so no light bounces back. Then a piece of glass on top of the film; the weight of the glass will probably hold it in good contact with the mesh, add weight around the edges if needed.

 

[hawaiianphatboy]

I would do what was suggested, but instead of a Halogen lamp i would suggest you use the sun for about 30-45 seconds. When my exposure unit goes down, i put the piece of foam covered with a black cloth on a cart, put the screen print side up on top of the foam and then place the image onto the screen. I would then put a piece of glass over the image and cover it with a black towel. I will roll it out into the sun and then remove the towel and time the exposure for 30-45 seconds. I will then cover it back up with the towel and take it back into a light safe room and wash both sides of the screen with a wet sponge coating it good with water and rubbing the emulsion to start the cleaning process. I would then take it to a wash out booth and clean it well. This has worked in a pinch and i have gotten great results. Good Luck and Aloha