Ghosting/shadow on print

[Gilligan]

I have been having some issues.

I have it working now but I'd rather the process be easier.

When I pull the squeegee, I'm not getting a good "clearing" of the screen.  I notice where the ink deposit isn't very strong there is still ink in the mesh.  Making me have to lay down some HEAVY ink.

I'm also having the issue of topic... after lifting the screen I end up with a shadow.  I think what is happening there is that as I flood the screen I'm putting some ink down.  I'm having issues flooding the screen obviously.  It just doesn't feel right.

So, what I started doing which has "resolved" the problem is push strokes and not flooding the screen unless I pick it up off the shirt first.

So I'm guessing my problem is off contact.  I am achieving my off contact by taping nickels to the screen at the four corners of the platen.

Is this not good enough or am I barking up the wrong tree?

[jsheridan]

So I'm guessing my problem is off contact.  I am achieving my off contact by taping nickels to the screen at the four corners of the platen.

If you have wood or aluminum screens with low tension mesh you may need to raise off-contact as much as 1/4" to get the screen to clear.

95% of all your print related problems can be resolved with screen tension, at a minumum mid 20's, using the glisten method of coating (front page) and increasing your exposure times.

[DouglasGrigar]

When I pull the squeegee, I'm not getting a good "clearing" of the screen.  I notice where the ink deposit isn't very strong there is still ink in the mesh.  Making me have to lay down some HEAVY ink.

Squeegee angle and pressure... ink in the mesh is often a lack of pressure, seeing that odd quote “kiss the shirt with ink” is difficult for manual printers because it makes us think of butterflies and fuzzy bunnies - look at the pressure, speed and angles used on an automatic and the invisible unicorn of “kissing the shirt” starts to make you wonder how it ever came about it just does not fit. Now digging in and laying lots of excessive pressure is also not the key and sadly for new people the best printing pressure, speed and angle change when the ink viscosity changes.

after lifting the screen I end up with a shadow.  I think what is happening there is that as I flood the screen I'm putting some ink down.  I'm having issues flooding the screen obviously.  It just doesn't feel right.

Could be you identified the problem also the phenomenon of “mesh rolling” caused by less than correctly tensioned / low tension mesh can cause.

So, what I started doing which has "resolved" the problem is push strokes and not flooding the screen unless I pick it up off the shirt first.

Diamondback L

The above is a youtube video of an automatic from MR showing the print and flood cycle up close - note that the flood happens after the substrate (on the platen) drops out of the way - flooding happens off the substrate, this is normal. Touch the substrate with the flood and a transfer of ink can happen.

So I'm guessing my problem is off contact.  I am achieving my off contact by taping nickels to the screen at the four corners of the platen.

Coins? is your press not capable of holding off-contact?

Is this not good enough or am I barking up the wrong tree?

More ideas are sure to come - have you considered making an video and posting a link in this thread to show the problems and how you are printing?

[Gilligan]

If you have wood or aluminum screens with low tension mesh you may need to raise off-contact as much as 1/4" to get the screen to clear.

95% of all your print related problems can be resolved with screen tension, at a minumum mid 20's, using the glisten method of coating (front page) and increasing your exposure times.

I thought of that also and that may very well be the case... BUT... this is a FRESH Pocono Screen (from flynbrian on ebay)... granted it is wooden frame and has been sitting in a box for at least 6 months (probably closer to a year.)

I am getting a drum tension meter in soon (another ebay) and that should give me a clue.  I know it's not "proper" but at $30 bucks vs $200+ hands down a good alternative... plus it was get an "idea" now or get the real deal in 4 years or something when I can justify that sort of purchase.

[DanK]

Sounds like you're flooding the screen with it resting on the shirt?  You need to flood the screen off the shirt.

[Gilligan]

Douglas... very thorough reply... I'll do my best to keep up with mine.

Squeegee angle and pressure:

I Tried different things here... my wife wanted to try some and she just couldn't get enough ink down to save her life... frustrated her and hurt her fingers trying to push harder and harder.  Push stroke still gave her issues but I think that was because she wasn't "on top of it enough"  There was a definite different in the ink left behind on the top of the screen after she pulled/pushed than when I did it (push strokes were almost squeeky clean, hers almost looked like a flood stroke   ). 

So basically we tried soft (unintentional) and hard and I varied the angles... but paid as much attention as I could to mimic what I have seen in videos and at my buddy's shop.  I have also watched his Brown Semi auto up close and paid attention to how it runs realizing that it was probably the optimal stroke given it was done by a machine.

mesh rolling

I thought about this myself... they are static wood frames... but they are quality ones (see above post).  Only thing that kept me saying that it can't be my screens is that my buddy's shop still uses static wood frames (larger ones, which I would imagine exaggerate screen tension issues).

Plus it seems that push stroke with no flood while screen was down seemed to have produced some sharp results.

Coins

LOL... simple answer is "what press".

Long answer is thousands of words (see pics attached, don't laugh)

Video

That is the first thing I thought about doing... but I couldn't be bothered with grabbing that tripod out from under my curing table and grabbing a flip camera... but seriously, I was just looking to get done with this job.  If I would have videoed it would have just given me a reason to stop for the night and I just wanted to push  through and get the job done.  110 shirts printed... transfers on about 24 so far.

BTW, this is a paying gig, BUT it is for a friend's convention so she is understanding of the few hiccups we may have and I have spares if some don't cut the mustard.

Pics

Don't laugh... I don't really have a lot of room to work with right now and this setup will get me by.  The main intention is to use this press in a "youtees" style.  The screens register to the platen with some "set screw" type of setup and you just pull them off to change colors vs rotating.  Obviously this slows down production but as I don't have a conveyor there is a bottle neck to speed right there.  Plus this system is said to have tighter registration then a cheap rinky dink carousel press.   But I'm already longing for a conveyor dryer as this job was a two step cure due to the size of the print and I would have been printing almost twice as fast if I had a conveyor.

This whole process is teaching me a LOT... it's also causing me to really pay attention to each print and I worry that I would get in a rhythm and miss some things... like I got a pin hole (for those that know my stencil method, don't ask :p ) I caught it on the 2nd shirt (granted it was getting progressively worse).

[Gilligan]

Oh and yes, those are small bungee cords on furniture clamps helping keep my screen up and out of the way... MUCH better than the first way I was doing it (all manual).

This is mostly prototyping to see how well those attachment points work on the screen and such.  If I put those "micro tuners" on the screens then they may just attach to those when used in a single color job and I won't have a need to add another screw to the screen.

That being said... this setup never really got in the way at all and I am lazy.

Pic of someone else's but essentially the same micro tuners.

[inkman996]

If you are getting a fuzzy edge when you do both a flood and print stroke that tells me either you are flooding much to hard and actually squeezing ink through the stencil or that you are flooding the screen and slightly contacting the shirt while doing so, if thats the case the flood is acting like a print stroke but in one direction then the actual print stroke is going the opposite direction creating the fuzzy edges. Simply make sure you are lifting the screen high enough off the platen before you flood and only flood enough to fill the mesh in. In fact take the time to flood and look under the screen and see if ink is being pushed past the stencil, if so lighten it up some. Amazingly once you get it figured out once it will be like riding a bike for you.

[JBLUE]

What mesh count are you using? I did not see that in the post. All of the above could be the issue. If your having trouble clearing the mesh and having to smash the crap out of it that can also give you a halo because now your smashing the ink out of the image area. Its just one more variable to think about.

[ebscreen]

I'd figure out another way of achieving off contact as well.
Coins hitting the mesh is going to do some weird stuff to your
mesh tension/off contact dynamic. Try shims under the screen in the clamps,
and a shim on the screen where it hits the top of the platen. (if it does)

Valiant first effort and better than my original attempts. I just used to hold
the screen in place and hope for the best. Even printed on my bedroom walls that
way.

[Gilligan]

What mesh count are you using? I did not see that in the post. All of the above could be the issue. If your having trouble clearing the mesh and having to smash the squat out of it that can also give you a halo because now your smashing the ink out of the image area. Its just one more variable to think about.

Sorry, it was discussed in another thread.  158 mesh is what I'm using... it's the highest I got.

Amazingly once you get it figured out once it will be like riding a bike for you.

Yes, I know... I went by my buddy's shop to use his spot gun and talked to his printers for a couple of hours today.  Watched him set up and print a job not much different than mine except that it was a much bigger area of ink.  I was quite envious of the results.  Even my good prints had such inconsistent and thick ink deposits.  His was nice thin and crisp.

But... his press had a LOT of off contact... at least a 1/4 of an inch... even he said that one has a crazy amount of off contact.

[DouglasGrigar]

his press had a LOT of off contact... at least a 1/4 of an inch... even he said that one has a crazy amount of off contact.

The lower the tension of the mesh the higher you are forced to compensate with off-contact, enough to cause the image to come out of the original shape and size.

BTW I am not about to laugh, we all started somewhere, some of your problems revolve around your equipment limitations.

[Denis Kolar]

What are you using to make stencil? Do you still use vinyl?

That might be one of the reasons.

[virgil427]

Try some shims under your hinges on the two by four to control the hiegth in the rear of your screen and tape some washers to the screen frame in the front mkeing sure they'll hit the neck area of the platten ,not the shirt and keep the shims off of the screen mesh. The other thing I see in your pics if your getting ghost image this suggests side to side movement bolt or screw some wood on either side of sceen probably two thirds of the distance from the hinges, just kiss the screen frame use these as your registration gate. And for what its worth i like your press that pretty neat.

[Gilligan]

Yes, I'm using vinyl... sticking it to the bottom of the screen (shirt side).  How do you think that is causing me problems?  I'm not second guessing you, I've just read of a lot of people using it successfully... now one guy's "success" might not be equal to your's or mine, hence why I'm here.  The vinyl has a Film Thickness of 2.8 mil.  So I'm creating a gasket effect with that like emulsion would.  Once I stopped flooding the screen while down, the images sharpened up (at least the edges).

Virgil427,  Yeah... the press is pretty Ghetto-rific!   I can't say for certain but I'm pretty sure I'm not getting any side to side movement... but I'll check when I get back home.  That 2x4 contraption is liquid nailed AND screwed together by 5 screws (of two different lengths)... that part is beyond solid.  I'm holding it to the press via screw type furniture clamps and they don't budge either but that would probably be the weakest link.  Well that and any slop in those jiffy hinges, but they are fairly tight.

But I am interested in your registration gate, but I'm not following what you mean.

For what it's worth... I have looked at the shirts with a fresh set of eyes and I feel like the flooding was my problem with the shadow print... as the ones that I did later did not have this issue.  My main beef with the prints as they stand now is consistency in ink deposits... mine are all over and generally too "thick" but with out the thickness I was missing spots.  I think this was due to too little off contact exacerbated by a low tensioned screen. 

I have another job of white on navy coming up this weekend with a few hoodies added to that.  I will see what I can do with that.  Speaking of, anything I should watch out for adding hoodies into the mix.  Obviously off contact will need to be raised... anything else?  What about curing under my flash?  Stick with the same as I have been doing (compensating for thickness?)