Still having problems clearing the screen

[Gilligan]

I just printed a few shirts and this was black on white on my manual.

Granted it's a static frame (200 mesh) and the tension is weak (11n-13n)... but still my off contact was high enough that I WAS actually clearing the screen... it just wasn't as clear as I'd have liked it to be... maybe I'm expecting too much.

I've read over and over you should be able to do one hit black on white and I'd agree with that.  But I can't get it... well, I do but not as well as I would like.  Not enough ink being laid down.

I'm flooding the screen firmly (as Bill Hood would say, "fill stroke") and then I try to push with as light of a stroke as I can to not bury the ink into the shirt.  When it's all said and done it looks "good enough"... but every now and then I get one that just a little weak in some areas and all the rest are so close to being weak.  This job was some half tone work so I couldn't really double stroke it or it would add too much dot gain... Granted part of that problem is my 25lpi being too large to make my halftones really pretty... but still, I should be able to do ONE hit right?

I tried slowing down, that seemed to help a bit.  I'm also using a triple durometer squeegee that is fairly sharp (certainly not dull).

What else can I do?

[mooseman]

There ia lot going on here based on some of the same stuff we discovered.
My first thought is you are trying to to hard to not to press too hard on the print stroke.
Being human the physical consistancy we apply is never the same twice let alone twice in a row. add to that you awareness of dot gain and weak screens you are what I will call limit faulting. You have set in mind a careful energy limit to the print stroke and every pass that does not acheive that target falls short thus your resuklts.
On the other hand when you have no concern for over pressure the limit fault becomes typical fault in that sometimes you  way over print and sometimes way under print but then will reprint when you visually identify a weakness of the ink deposit.
Bottom line it is in you art, lpi, weak screen tension / off contact and mostly your tecnique and awareness .

One last comment and this will get me banned possibly...i have stopped reading anything Bill Hood wrights, he seems, in my opinion, to have a purist + utopian view of the the world he lives in which I find absolutely no relative association to reality. Bill, i believe, prints on another planet where everything always works perfectly first time every time.
mooseman

[Frog]

To Gilligan, I'd say that you either need more muscle or thinner ink. Also, if there is any consistency at all to where the ink doesn't clear, you may want to look at your pallets for unevenness.

To Moose, I have to reassure you that your particular comment here about Bill will not get you in trouble, and I will even point out that though I have tremendous problems with his delivery, I will be one of the first to say that he is a fountain of knowledge. Just bring your rain gear.

And I also like the term "fill". We are in fact, by flooding the screen with ink, filling the image area, in preparation of transferring it to the substrate.

[Gilligan]

Yeah, one hit white on black seems impossible no matter how many times I watch his videos so I can appreciate your point of view there.  I only used it as a reference to exactly what I am doing as not to confuse anyone when I tried to describe what I did (and save you guys a paragraph of my typing. )

Frog, pressure I think I got... I mean these were light weight tri-blends but I was getting ghost images on the platen at times so I know I was pushing hard... this led me to lighten up thinking I might be driving it too deep.  I actually find it hard to lighten up (in my perspective) when you use a push stroke... My squeegee is at maybe 20-30 degree angle (from vert).  I feel if I want to lighten up I have to increase my angle or I can't get the squeegee to get moving with out adding downward pressure.  Again, I'm sure my technique lacks a lot.

As far as consistency and possible platen problems... I guess I might should clarify what I mean by not completely clearing.  It almost leaves the screen with a slight peppered look.  It's not blotchy it's just specks of ink in certain sections.

I attached a pic that has a slight example... I'd say I had a little bit more of that going on in my screen last night.

This is why I tend to think it's just the amount of ink getting laid down.  Maybe I should thin the ink?  I stir my ink a good bit before I load the screen and then I work it in the screen a bit too.  Once I start printing I print at a decent rate (30 seconds a shirt),  not blazing but I'm keeping the ink moving.  It's not ridiculously cold in my shop or anything... upper 60's lower 70's maybe?  I didn't have the Central Air on but it was cold as hell out last night (my building is well insulated).

[pwalsh]

Gilligan:  Garment Screen-Printing is an interesting process where sometimes the solution can be counter intuitive to what you would expect.  For example, you’re not getting enough ink lay down so the obvious answer is to push harder, or to use a softer squeegee and/or an increased squeegee angle.  Maybe the ink is too thick so it should be thinned down some.  But,  you’re already getting a ghost image showing through the garment and onto the printing pallet. This could mean that the ink is already too thin, and that reducing viscosity will only add to your problems.  What to do, what to do? You need to remember Rule Number 1. and get back to basics, because all of the problems that you are experiencing could be the result of not having your press and stencil mechanics under control. 

IMO you need to get set-up with a couple of sharp squeegees of varying durometer, you need to have a selection of screens of varying mesh counts that are tensioned at 20N or greater (25T to 30T is better), you need to ensure that your stencil provides a suitable amount of Emulsion Over Mesh (EOM) to provide a decent gasket to allow the ink to release, your press needs to be set with the correct level of off-contact for the garment and the ink that you are printing with, and finally you need to apply the correct squeegee and floor stroke speed, pressure and angle consistently throughout the run.  Bottom line, other than mixing the ink well before printing I would not be messing with it until after you address those other issues first.

[jasonl]

adjust your off contact!  that is your problem.  From what your describing, thats how I would fix it.

[ZooCity]

Well, when you get some decent mesh stretched up on those MZX's you might see an immense difference, check that email.

I had success with one pass white on statics way back using the "what the hell is that long-bearded Texan doing in that video" approach but only on 135 and down which meant they were about 20n/cm.  As Mr. Walsh pointed out, this appears to be the line for tension.  Under this and problems abound that aren't worth the energy to troubleshoot.  Up the tension and move on to happier printing.

Kudos to Bill, bless his heart, for promoting the concept in layman's terms (that Joe Clark lays out in much more technical detail) of plastisol printing being a load/eject process with proper loading and good shearing/pumping being the ticket to laying ink onto rather than into garments.  But as you've seen others alluding to, the guy is a little too far out in right field on some things.  I've never seen a video of his that showed a true one hit white by my own standards.  They are often tan ink prints which makes a very big difference in ink rheology and, if you were to look closely at many of these you'd find them to be inferior to a p/f/p with an underbase on a higher mesh counts. 

So don't get juked by those videos into thinking that one hit whites are something you need to be doing on a daily basis.  They are very possible and superior to flashing one certain print runs but require the wrangling of many of the variables that seem to be running wild for you right now.  Once you get the screens tensioned up, the press in good parallel and the eom under control, revisit the idea.   

But you should be clearing your white ink in a single pass.  You know from working on press how critical this is to avoid excessive gain and have a smooth and registered underbase.  Take that mesh count down and thin the white a tiny bit at a time until it works. 

The little pock marks in the print, I get those too sometimes.  They're frustrating and a mystery to me but I think it has something to do with the fill stroke and fill/print speed.  I often resolve them by doing a dry stroke to clear.  I want to clarify that this isn't the shape and texture of the matted down fibers you're seeing but little tiny craters in the white print?

[jason-23]

Your expecting to much, it's just printed underwear for God sakes! Hit it twice, move on and go fishing or hunting would be better this time of year.

[Prosperi-Tees]

I got a batch of black ink from international coatings that was so thick out the bucket that my arms hurt trying to work it. I had to add about 20% reducer to get it to flow right.

[Inkworks]

I find off contact or squeegee angle to usually be the culprit. Shear the ink and get a good rolling peel behind the squeegee.

That said, just hit it again and get on with life is good advice.

[Gilligan]

Bottom line, other than mixing the ink well before printing I would not be messing with it until after you address those other issues first.

Thanks Peter, I read all of that (not just the quoted part.. just saving space).  I agree and I plan on fixing a lot of those issues.  As Zoo said, I got some mxz's that I'll be setting up soon.  I'm just using what I got now to get jobs done.

adjust your off contact!  that is your problem.  From what your describing, thats how I would fix it.

Hey Jason, in what way.  I'd say I have 3/16s of an inch OC and it LOOKS like it's pealing just find behind the squeegee.  I notice when the shirt isn't sticking to the board the difference so I think it is pealing properly behind and that I have enough OC.  Unless you are saying I might have TOO much.

I'm on an Antec legend with rear clamps and I set it up with a TINY bit of umm.. "slope" from front to back.  That way as the weight of pushing on the squeegee happens it makes for "level" off contact.  This may be completely wrong but it made sense in my head.  I set my OC by pushing on the screen to the platen in the back and seeing if the OC levels out.

Well, when you get some decent mesh stretched up on those MZX's you might see an immense difference, check that email.

I had success with one pass white on statics way back using the "what the hell is that long-bearded Texan doing in that video" approach but only on 135 and down which meant they were about 20n/cm.  As Mr. Walsh pointed out, this appears to be the line for tension.  Under this and problems abound that aren't worth the energy to troubleshoot.  Up the tension and move on to happier printing.

Oh, no I'm not worried about one hit white any more.  I'm just using that technique to improve my one hit dark ON light.  I was printing BLACK ON white, not the other way around.  I will be PFP'ing as that one hit white never works.

But I agree, I'll be getting those mxz's up as soon as possible (with in reason of my lazy arse will) .

I find off contact or squeegee angle to usually be the culprit. Shear the ink and get a good rolling peel behind the squeegee.

That said, just hit it again and get on with life is good advice.

Yeah, I think I might try going 35 LPI... maybe 45... but that is part of my issue I think.

This artwork was funky to start with... he approved the test print so I went with it. (no, I don't test print for many people.. he's a friend that had had some bad experience with printers not knowing how to print half tones.)

So basically the enemy that I'm battling here is tension?  I can accept that.  I'd try to understand that more sense I know so many shops running statics but then again, I also see that they don't do that good of a job with them very much.  Their auto's help them get through most of it I think.

[jasonl]

Here goes my spill on newmans vs. static.  Newmans are great if you maintain and retension and can build them perfectly.  I used them for 14 years and just assumed they were the norm.  I recently quit the big shop I worked for and opened my own shop, and guess what?  I switched to static frames and I will NEVER look back!  By far easier to use, clean, purchase, maintain, and you know what else?  I CAN PRINT JUST AS GOOD WITH THEM!  There has not been even 1 frame to bust since I started to use them.  We used to break mesh in newmans EVERYDAY.  Again, if you got a full time guy who can maintain newmans correctly, they are good.  But, do you?  We ran 4 Large autos and 2 manuals and never had time to retension and maintain them as you should.  If you don't, they are not even as good as statics.  This is my opinion after 15 years of screen printing. 

[Gilligan]

But there are small, even one man shops that use them with a different experience.

I'd actually venture to say that you would bust less screens with a smaller operation than a large one.  Ask Alan how many he would bust if it was just him.  He sees those guys throw them around with out a care for them... that is part of the problem with larger shops.  Employees just don't give a crap as much.

[Screened Gear]

Black ink on a white shirt can be a pain manually. I know what you’re talking about sometimes the ink does not look dark enough. I see this sometimes when I pull the shirt off and put it on the dryer. When this happens I almost always thin my black ink down with reducer. What your doing is not getting enough ink down with enough pressure. The ink that is on the shirt is not penetrating the fibers enough.

Black ink on a white shirt is not like white ink on a black shirt. You don't print them the same. You don't modify your inks the same. Off contact for black ink is not important. Tight screens for black ink is not important. This is the easiest print you can do. You are trying to do it like a white ink print. Thin the ink and print it hard.

In is video you can see the way I print manually. I do a flood stroke then a print stroke followed by a clear stroke. Some people would say its over kill or just another step. I do it to make sure the print is right. With the clear stoke you are making sure all the ink is out of the stencil and on the shirt. (printing this way also works great for white ink)
 
Hope this helps.

1 color screen printing with halftones on t-shirts

[Gilligan]

Wow... ok, I'm printing WAY harder than that... even when I'm trying to be light about it.

How much off contact is that?

I guess I need to drop my handle down some and increase the angle.  I'm coming up way higher and pushing way harder over the top of my squeegee.

Interesting.