Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
I agree. 20-25 ncm is recommended depending on mesh count. We at Xenon get these tensions everyday. What could be happening, is that you are not properly preparing the aluminum screen for re-stretching. To properly do this means removing the glue and any residue mesh from the screen frame without removing aluminum from the screen. Also pre-tensioning the mesh is recommended as well. We at Xenon pretension all of our mesh before it is clear to the frame. We also put the frame through a multistep prep procedure to ensure proper adhesion of the mesh to the frame. If you have any more questions please call me at 404-895-1796.
In a nutshell, about 20 n/cm is the min tension to avoid a host of printing issues. Below that, you invite issues like image distortion, difficulty registering and peel/ off contact problems. You can work around these, many have and still do and make great prints.
Last approach you might consider, if you want to stay with statics, is to find a skilled stretcher who can handle delicate mesh and properly stage tension it and have them stretch thin thread mesh like Murakami S mesh, which performs well at lower tensions. Expect to pay more for this, presuming you can find someone nearby to do it.
We haven't had any problems with screens popping or coming off the frames, they all seem good as far as that goes.Nick
We run panelframes and newmans. The panels we stick to 110s and 160s almost solely since other mesh counts just print crappy compared to our newmans. Any jobs above 100 shirts I won't accept the panelframes on pretty much, their tension is much better than statics but still not what is recommended. Even ink suppliers / manufactures recommend 25N minimum on every screen.Our panel frames come out to 18-24N usually and work fine on the manual but I want to stick to rollers on the auto to not run into issues / slow downs.I can't imagine what you are doing to get good prints out of those screens. You are underbasing with a 160 at under 8N? I can't imagine trying to get that to work out..and wet on wet printing...Anyway find a good supplier/restrecher for statics and you will be much better off, you want a minimum of 20-25N on standard mesh counts.
Nick you have quite a few problems you need to address beyond tensions and it sounds like you know that. I would get a good collection of screens that are between 18-25 nm. You guys do not need to be messing around with higher tensions than that right now with the turnover of employees and improper printing practices. From the sounds of it your low cost wages are costing you far more than you guys are saving. If you guys had a printer that knew what they were doing that press would only have to go around once. Flashing every color and hitting it twice is not the way to go as you already know.It sounds like you have a idea of what's wrong and are pointing yourself in a good direction. You guys should really look at having someone come in for a few days and do some consulting or see if you can get some hands on at another shop.
Also, it is possible that your meter is way off. Being that you "found" it laying around and don't really know it's calibration.See if you can find another printer or have a supplier bring over one and A/B test them. Not fool proof but it will give you an idea, it's unlikely they will both be off roughly the same. One will likely be right and the other will be wrong. But in that case it doesn't answer any questions as neither one of you will know which one is wrong. Example, your meter could be low, or maybe your screen supplier's could be reading high. Both would attribute to low numbers on your meter but neither answers what tension you actually have on your mesh.