Let’s talk about some common problems that you may encounter when coating your screens with emulsion. This can be one of the most frustrating things when you start printing because it looks so simple and easy on the YouTube video you just saw.
Here are a few key points to remember when going to coat your screen. Do not over fill or under fill your scoop coater. Fill it about half way and make sure the emulsion is spread throughout the coater evenly. Second you want to hear contact between the mesh and your scoop coater, don’t be afraid to apply pressure to your screen. Next use whichever side you prefer on your scoop coater, some people will tell you to use the thick edge and others will tell you to use the thin edge because its better. The truth is, it’s up to you, the thick edge will lay down more emulsion and the thin side will lay down a thinner layer, but what if my scoop coater just has one side? That’s why it is up to you, the printer.
Ok so back to running through some uh oh! scenarios with your emulsion. So, pressure and speed are the first and foremost important to tackle and get right! Without the right pressure and speed during coating you will get thin, non even patches of emulsion. If you go slow and do not put enough pressure you will have a biiiiiiig mess on your hands, it’s not fun and sucks to clean up.
Next up... sometimes we coat screens and notice a streak or lines in the coat. Look at your scoop coater and check the edges, do you have any dried-up particles of emulsion or anything else that may be sticking to the edge of your coater? Also check for dust particles or anything else that may have landed on your screen that could cause lines or flaws in the emulsion during coating.
Sometimes we have some emulsion particles peel or start to flake off after exposure. This will happen when you expose and wash out your design out. This can and will most likely happen because of uneven coating or bad emulsion. You need to make sure you coat evenly and don’t try to go back and patch certain areas you missed. Patchwork will double the emulsion in the area that you had already covered. This is an all too common problem with new printers, they end up with super thick coats that take a lot of water to spray the image out; the image and the unfortunately the emulsion come off too in this case. Another factor for emulsion peeling is film positives but we will cover that in another session.
Finally, lets talk about reclaiming. Sometimes screens can be hard to reclaim after the print job. The first thing is to make sure the screen has been properly exposed and cared for. A popular issue for having a screen that is hard to reclaim is letting your emulsion remover sit to long on the screen. Now a lot of noobies think “hey maybe if I let it sit a little longer it will penetrate better”…. WRONG! If you let the emulsion remover sit longer thinking it will work better it’s going to do the complete opposite, it will make the screen irreclaimable. Irreclaimable = that emulsion is not coming off any more! yikes :/ An easy way to prevent this is to follow the directions on your emulsion remover containers, simple right? Another thing is to use enough water pressure. Some will say that you need a pressure washer to reclaim screens but if you look around online you see that most of the time unless you have used hardeners that’s not the case. A lot of printers use a normal garden hose with a pressure nozzle.
Yea that's enough for this Blog post although I could keep rambling, we have heard every problem. Remember if you have any questions drop a comment below on this blog or reach out on Instagram or our live chat.
Till next time people.