Aquasol HVP help

[TCT]

Hey guys, I have been out of the shop this whole last week at the hospital with my son and I could really use some board help! Seems like everything that can go wrong or "off" at the shop is happening all at once.

We use Aquasol HVP, and the guys at the shop are saying it is breaking down with discharge jobs. Here are the details-
-Screen room is about 50% humidity
-Screens are burned , exposure time should be correct I usually do a step test every month or so to keep up with the bulb aging and just to be safe.
-Screen is washed out
-Screen drys
-Apply hardener MS
-Set the screen outside in the sun(kind of a cheat I use instead of post exposing) *I have a feeling this may be the issue*
- Block out anything that needs it
-Print

Apparently the screens are breaking down or becoming extremely brittle around 150ish prints.


I am ridiculously behind on emails, quotes, questions, and just about everything you can imagine now. My brain feels partially there but I can't make any sense of this. I can't get in there to troubleshoot now so I could really use some help on this one.

Any thoughts or suggestions?

[Frog]

Is the hardener usually applied after post exposure?
And I really think that even a 10,000 watt, super duper MH has nothing on the sun, the ultimate single point ultra violet light source.

[volker]

hey alex,
i really hope your son will be alright soon. your familiy has my best wishes!!!

you are using a pure sbq i believe. we do not have this product in germany so i googled it and it seems to be a pure sbq.
if so we made the same experience with spq and believe that all people who sell you that stuff do not say the truth when they say that it works with discharge. hardener did not work on sbq at all also.

thats why we use the good old diazo emulsion on discharge, which is slower but it works fine. the hardener makes it really harder and 2nd exposure in the sun works fine. little holes in the emulsion should be closed/filled with the emusion itself because some fillings get washed out or can not be removed easily.

since we use certain emulsion for certain jobs, we do not have problems anymore.
hope that helps.
best regards and again best wishes for your son
volker

[mimosatexas]

I use Aquasol HV (not pink cause i'm not a girly man etc) but we run discharge through it all the time and have done quantities up to 700 without failure.  We single coat each side, expose, dry, post expose, hit it with the pressure washer (this step clears up any emulsion bleed which seems to be a somewhat common issue, basically like a thin film that drips across the stencil during drying.  Also tests the durability of the stencil), use MS hardener, let it FULLY dry, tape, register, print.

I think the extra steps sort of negate the quick exposure and ease of use of the aquasol, but I refuse to switch since it just works so well for everything.  I don't have enough volume to justify storing multiple emulsions and risk losing a diazo batch to some small factor due to its pickiness.  The aquasol can sit in the sun for months and work fine.  It's great.

When we have had break down it was due to hardening before post exposing or failing to post expose alltogether.  Even without hardener we have had a post exposed screen last toward a hundred prints on discharge. 

We use matsui discharge.  White is the only ink that we are extra careful with and monitor breakdown more closely.

[TCT]

WOW! Have we really been doing the post exposure and hardener backwards all this time!? That actually doesn't surprise me that much, I am real good at reading and flowing 50% of directions and instructions.... Just the other day I was "showing" someone that was in the US for the first time, how to drive down a one way the wrong way
Thanks guys, pretty embarrassing that I had that backwards. But pretty small in the whole scheme of things I have learned this last week.

Thanks Volker, my little man is still in pretty rough shape, the doctors keep saying "give it another 24 or 48 hrs.".
Wish that could be my answer to customers sometimes! 

Thanks again guys.

[blue moon]

good luck with the little one, please give me a call if there is anything we can do to help!

As far as the Aquasol, we seem to be in the same boat. There are provides a little bit of releafthings we do different from the others and they might be the cause of the issues. 1st, we are on metal platens which might be the cause of the premature breakdown. The rubber provides a little bit of relief to the pressures exerted by the squeegees. 2nd is the fact that we coat very thick with 50% EOM on the 110's. Thicker emulsion layer might not be as flexible and it might possible it is the main cause of the premature breakdown. We use the hardener like you, and are seeing similar results. 'had no time to tackle it as we are super busy, but we will need to address it when it slows down a bit.

pierre

[mimosatexas]

I have read elsewhere and it has been our experience that with discharge a thin 1/1 coating gives the best results.  I don't know the reason.  We use basically all 156's for discharge and the occasional 230 (very rarely).  I have heard others have issues with jantex discharge, but with matsui we simple don't have the breakdown many people complain about.

[TCT]

we are on metal platens which might be the cause of the premature breakdown.

pierre

That is interesting! Because the press we are having the screen failure on has metal boards also....
I am going to send a email over tomorrow to have the guys try the RIGHT way to post expose and then harden, but I will also ask if there has been any screen failure on the other press which has rubber boards.

[brandon]

Hey Alex, not too sure what's going on with your family but I hope everything is ok. I am currently in the middle of a move across country and out of the loop. But before I sold my business I was training some of the staff on discharge runs and the proper screen prep. We used the same emulsion with production runs in the thousands with not a single pinhole breakdown. Proper exposure time, block out any pinholes if any, no reg marks, and post expose. Then apply hardener. My two first thoughts would be :

1. Is your exposure time correct?

2. Are you doing this at least 24 hours before you run the job or right away? Any time there is a "rush" job and the screens are prepped that morning and printing an hour later is when problems seem to arise. Not all the time but if there were any problems that would be the cause. Oh, and no tape on shirt side of the screen. Ever. That will cause breakdown as well as the screen cannot "breath." Hope some of this helps.

Oh, and we added the diazo as well

[IntegrityShirts]

I had similar problems a little under a year ago with HVP in the dead of winter.  Even with plastisol the outside edges of the emulsion were cracking and wearing through.  I attributed it to cold pallets ("soft" top rubber sort of curls up at the pallet edges and is pretty sharp) AND a bad bucket of emulsion or two.

Ended up taping the edges of the squeegee path and switched to regular HV and problem went away, but I can't say for sure what the cause was.  I have since switched back to the HVP and haven't had any wear-issues with plastisol or water-based.

I expose, wash out, and dry in the sun for discharge/water-based runs under 100 pieces.  I harden above 100 and haven't had any issues this year, knock on wood.

If either of you have a new gallon of HVP, coat a few and see if it's a bum gallon of emulsion!

[mimosatexas]

As brandon mentioned, drying is really important.  The screens really need to be bone dry after each step or else you may see issues.  Also, if you have any ghost images, they may not affect exposure, but we have had a weird issue here or there when we had a really badly ghosted screen.

[blue moon]

anybody here with metal platens and success printing discharge with Aquasol?

pierre

[mimosatexas]

We use mdf coated with melamine.  No rubber, but more give than straight metal I would assume (though not much...)

[Extreme Screen Prints]

We have Mhm honeycomb pallets and do not have breakdown, The best way to coat is super thin 1 and 1 coats and use a a&b reclaimable hardner if running 3,000 or more pieces. Stencil thickness is the killer and not having your humidity level below 30% in your screen room. If there is water still present in the emulsion you will breakdown. Metal or rubber makes no difference , we have rubber on 1 press and the other doesn't and we see no difference.

[blue moon]

We have Mhm honeycomb pallets and do not have breakdown, The best way to coat is super thin 1 and 1 coats and use a a&b reclaimable hardner if running 3,000 or more pieces. Stencil thickness is the killer and not having your humidity level below 30% in your screen room. If there is water still present in the emulsion you will breakdown. Metal or rubber makes no difference , we have rubber on 1 press and the other doesn't and we see no difference.

my understanding was that the a&b combined make it permanent. Are you reclaiming the a&b coated screens? We use the one part and it does help significantly. I will make sure to try the thinner coats as we are very, very thick.

pierre