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screen printing => General Screen Printing => Topic started by: BartJY on August 04, 2018, 10:52:11 AM
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Hi Folks,
Quick question: Regarding a four color press. When you bring down the screen to print on the shirt, should the screen be in direct contact with the shirt or just short of actually touching it?
Thanks
Bart
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With plastisol ink there should always be some amount of off contact. Typically in the 1/16-1/8" range. The amount of off contact is usually dictated by screen tension, the tighter the tension the smaller the off contact.
Butch
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If your carousel doesn’t have a off contact adjustment you can tape something under the screen to stop to going down onto the shirt.
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I thought there should be some "off contact" when placing the screen.
Thanks for the conformation.
Bart
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Any one use shims or rasta bars ?
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I thought there should be some "off contact" when placing the screen.
Thanks for the conformation.
Bart
Note that this applies more to plastisol ink that should be sitting on the surface of the fabric rather than the waterbased inks that are driven into the fabric.
Although now a few years old, there are a few books that could answer a lot of your questions, and are considered pretty standard references.
https://www.amazon.com/Screen-Printing-Today-Andy-MacDougall/dp/0944094619 (https://www.amazon.com/Screen-Printing-Today-Andy-MacDougall/dp/0944094619)
https://www.amazon.com/How-Print-T-Shirts-Fun-Profit/dp/0981581609 (https://www.amazon.com/How-Print-T-Shirts-Fun-Profit/dp/0981581609)
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I don't know what rasta bar is, but shims went out the window about 35 years ago for us. Most good manuals have an off-contact adjustment.
Steve
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I don't know what rasta bar is, but shims went out the window about 35 years ago for us. Most good manuals have an off-contact adjustment.
Steve
Rasta Bars were M&R's color coded shims.
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Go to youtube search the term "off contact"...........................
mooseman
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(https://media-cdn.tripadvisor.com/media/photo-s/0e/cf/4e/b8/rasta-bar.jpg)
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I'm guessing that the M&R Rasta Bars were color coded in red, green and yellow as well
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I don't know what rasta bar is, but shims went out the window about 35 years ago for us. Most good manuals have an off-contact adjustment.
Steve
I still use shims on a back clamp manual.
It's true that the press has off-contact adjustment....but....when you run the squeegee (push or pull), there is no way the back clamp can maintain the off-contact and the screen will drop down on the substrate effectively negating the off-contact setting.
Possibly a side clamp press may not have this issue, but my back clamp Workhorse does.
I simply cut up a thin yardstick into 10 or 12 inch lengths and tape to the underside of the screen front edge (and sometimes to the back edge also to avoid any issues with the arm flexing) so the screen frame maintains the desired off-contact through the entire stroke allowing the screen to do the "wave" laying down ink.
I may be in the minority, but it's what I do.
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I don't know what rasta bar is, but shims went out the window about 35 years ago for us. Most good manuals have an off-contact adjustment.
Steve
I still use shims on a back clamp manual.
It's true that the press has off-contact adjustment....but....when you run the squeegee (push or pull), there is no way the back clamp can maintain the off-contact and the screen will drop down on the substrate effectively negating the off-contact setting.
Possibly a side clamp press may not have this issue, but my back clamp Workhorse does.
I simply cut up a thin yardstick into 10 or 12 inch lengths and tape to the underside of the screen front edge (and sometimes to the back edge also to avoid any issues with the arm flexing) so the screen frame maintains the desired off-contact through the entire stroke allowing the screen to do the "wave" laying down ink.
I may be in the minority, but it's what I do.
Problems with this may have been the case more with wooden frames with loose corner joints, but for me, I find that the rear clamp, off contact works as advertised with aluminum frames. Pops off just fine. (assuming that the screen level/tilt adjustment is also set correctly.)
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i used to keep paint paddles around for the old gauntlet. If I was running sweats just pop them in under the frame and boom...done...until you forgot one, or all of them.
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I'm guessing that the M&R Rasta Bars were color coded in red, green and yellow as well
I'm pretty sure they were.
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Wooden paint stir sticks from Home Depot/Lowes. They are free. I use them every now and again, especially on fleece.
Butch
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I don't know what rasta bar is, but shims went out the window about 35 years ago for us. Most good manuals have an off-contact adjustment.
Steve
I still use shims on a back clamp manual.
It's true that the press has off-contact adjustment....but....when you run the squeegee (push or pull), there is no way the back clamp can maintain the off-contact and the screen will drop down on the substrate effectively negating the off-contact setting.
Possibly a side clamp press may not have this issue, but my back clamp Workhorse does.
I simply cut up a thin yardstick into 10 or 12 inch lengths and tape to the underside of the screen front edge (and sometimes to the back edge also to avoid any issues with the arm flexing) so the screen frame maintains the desired off-contact through the entire stroke allowing the screen to do the "wave" laying down ink.
I may be in the minority, but it's what I do.
Problems with this may have been the case more with wooden frames with loose corner joints, but for me, I find that the rear clamp, off contact works as advertised with aluminum frames. Pops off just fine. (assuming that the screen level/tilt adjustment is also set correctly.)
Yes, I cannot remember the last time I did a rear shim. The rear holds the off contact okay. It's just the front that dips down from exerted pressure during squeegee stroke.
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I don't know what rasta bar is, but shims went out the window about 35 years ago for us. Most good manuals have an off-contact adjustment.
Steve
I still use shims on a back clamp manual.
It's true that the press has off-contact adjustment....but....when you run the squeegee (push or pull), there is no way the back clamp can maintain the off-contact and the screen will drop down on the substrate effectively negating the off-contact setting.
Possibly a side clamp press may not have this issue, but my back clamp Workhorse does.
I simply cut up a thin yardstick into 10 or 12 inch lengths and tape to the underside of the screen front edge (and sometimes to the back edge also to avoid any issues with the arm flexing) so the screen frame maintains the desired off-contact through the entire stroke allowing the screen to do the "wave" laying down ink.
I may be in the minority, but it's what I do.
Problems with this may have been the case more with wooden frames with loose corner joints, but for me, I find that the rear clamp, off contact works as advertised with aluminum frames. Pops off just fine. (assuming that the screen level/tilt adjustment is also set correctly.)
Yes, I cannot remember the last time I did a rear shim. The rear holds the off contact okay. It's just the front that dips down from exerted pressure during squeegee stroke.
Yes, it may dip down during the stroke, but it's just that that doesn't seem to affect my registration or prints, but rather is just part of the off-contact process/effect. I suppose with excessive off-contact, this could be a problem.