Spots on printed tee-shirts

[Benvdb]

Hi everyone,

I have a very annoying problem when it comes to printing t-shirts. Every time i print a shirt i have some sort of dots on it, they look like drops.
It seems like i use too much ink but even with less ink i have it. There are no puncture holes or nothing. The ink is very thick though. My snap-off is about 4 mm. It's white ink called UNITEX OP OPAQUE WHITE OP 110 (http://www.unico.be/products.php?action ... up=41&ID=2) from a Belgian company called Unico. I don't dilute it i used it like it comes because i don't know how much i need to dilute it properly.

[Catspit Productions]

If you don’t have any pinholes then that is indeed a mystery. Can you upload a photo?

[Benvdb]

Here are some pictures, not the best quality though. I have been thinking could it be that the off contact is to high? It really looks like spludges that got on the bottom side. I really need help i've been having this problem for a while since i have a printing table where i can adjust the off contact before i just clamped the screen on a table without off contact and i didn't have the problem.

[drew]

The only thing I can think of is maybe you are flooding to hard? That wouldnt make just one big spot though. I would try cleaning the bottom side of the screen, double check for pinholes and try not to flood very hard. I'm interested in hearing about the cause of it. I haven't seen this before.

[ApeShirt]

Have you used any type of screen wash or screen opener on the screen? From the pictures it looks like not only splotches but also streaks. They also look "diluted". Using screen wash or screen opener and not wiping the screen thoroughly could be a culprit.

[Benvdb]

No the streaks are because i took the wrong squeegee and didn't notice it on time i was a bit whoozy that day. I also discovered that someone used my table because the off contact was a about a cm. Could it be that that is the problem? I did use screenwash but already after i had the spots because there was ink on the bottomside because of the spots. Before i started the screen was completely clean, i printed and had spots.

[drew]

What screens are you using? If that's water base and your using a low screen mesh(110) with high off contact and flood hard, the ink may be puddling or dripping right through the mesh. I don't use water base but maybe try a higher mesh screen, like a 180 or 200 and see if that helps. Just and idea.

[Dip.Schlitz]

Could be caused by ink separating in the bucket and this is the plasticizer smearing through the screen. I have this problem with high opacity plastisol inks time to time. It's easily remedied by giving your ink a stir before loading it on the screen and then knead it for a bit before printing.

[Catspit Productions]

Okay, I can’t tell what is going on from these images. That is indeed a strange spot. It looks as though the ink dripped through the screen. If you can clean up the screen and post a few pics of these spots on the screen where it is happening in the print, then maybe I can take an educated guess.

So if I can see the stencil where this problem is occurring then we may be able to determine if it is the stencil or the ink.

[Benvdb]

I solved it! I feel like such an idiot! I made my own press and platen there's nothing wrong with it, i can adjust it in height and everything. But today i found out that it it's the platen i made. The spots are cause by screw holes in the platen. I screwed everything together from the top of the platen, and the spots match exactly with the screw holes so i'll fill them up and then it's solved. Thanx for all your help.