Okay, so I've read a number of postings about this issue and I've had so many different opinions from people I've met and I'd like to get it straight from the mouth of someone who has done, does it and is doing it successfully.
I currently don't have the funds to purchase a flash dryer. I just spent what I had to get my press and a heat gun. I did this because one: I didn't know about plastisol transfers & heat presses; and two: because one of the guys from the shop that makes my screens suggested using a heat gun. Anyway, I am using a Wagner HT1000 DUAL TEMP (750 & 1000F, Power 1200 Watts/4100 BTUs) and have a small 4 color tabletop press (love the press!). I am printing mostly black ink on white tees and white ink on black tees. So far, I've had more problems with the black ink than the white. So, I have been screening tees (one and two colors) and flash curing inbetween colors and then doing a final cure at the end, all with a heat gun. The guy from the screen shop said one shirt should take about 3 to 6 minutes depending on the size of the graphic. Most of my graphics are fairly detailed and my biggest one as of now is 12x17. This one takes the longest. For testing purposes, I printed a bunch, cured them and then washed them. Some remained perfect, jet black ink on white and others faded big time. I just can't seem to get the timing right. I've used other colors and the same happened - some perfect and others fade.
So, will anyone who has made this work consistently please tell me what you are doing and how you are doing it? I have a friend who has a flash dryer who has agreed to flash cure some for me but I'd have to cure them enough to deliver them to him. The problem is, he lives very far away so I can't always get them to him and I finally have people wanting to buy my tees!
Any help would be extremely appreciated... Thank you
Bula from Fiji.
We are a professional screen printing company and have been printing for 4 years. No flash unit.
We have a 6 colour carousel. We normally flash a colour we are printing only when doing something like putting a white ink down on a black shirt and then printing red over it so the red stands out. To do that we print the white and then use the heat gun at high temp and about 10 - 12 inches away for a certain count. You have to determine this yourself but we use anywhere from 6 to 10 seconds moving the heat gun constantly over the ink. When the ink is touch dry you are done. Remember a flash is NOT curing. You just want to put a crust on the ink. As for curing....it does not take too long as the temperature is very high. Try 20-30 seconds and do some wash tests. Also remember you can do wet on wet as long as you have a bit of lift off so you really do not have to flash every colour unless you are printing over it. We regularly do 4-5 colour prints wet on wet...no flash.
Thank you very much for the info. That was precisely what I needed to know. I was beginning to stress because as mentioned, a handful of my tees faded only after the first wash and I thought I wasn't going to be able to get the gun to work. We are on strike right now so no monies coming in for who knows how long and since I now have a great amount of free time, this t-shirt business seemed like a great plan to supplement my invisible income! lol I was thinking I was going to have to come up with another few hundred dollars just for a flash dryer which would then of course cut into my ability to get the blanks and so on and so on... I am feeling far more relaxed after your posting. I am going to go give it a go right now.
Thanks again and I will post back with the results. Thanks WindwardApparel!
When it comes to the final cure with the heat gun, do you recommend curing it while the tee is still on the platen or removing it? I have been hanging the tee and then blasting it with the heat gun. I thought that would be good because the heat could pass through the back of the tee as well but I don't know if that is actually good to do or not. Maybe there is a benefit to having the base that the tee is rest on getting hot as well. Would you mind letting me how you guys do this?
Also, I tried what you said and 2 of the 3 test tees worked out perfectly. I had a jet black (large) graphic on a white tee. After curing it with the heat gun I washed it twice, back to back, and the graphic remained solid and jet black. On one of the three, part of the graphic faded. I just have to get the system/process down I'm sure.
DO NOT take it off the platen. You are simply curing the ink which means you melt part of the ink into the cloth. When you leave the shirt on the platen the heat is directed specifically at the ink and also the heat reflects back from the platen, thus reducing the time needed to cure.
Cody, thank you very much. I just tried this out printing white ink on a brown 50/50 tee. I printed the white, did a 20 second flash (its a big graphic), printed the final layer of white and then spent roughly 30 seconds on each section of the graphic... again, it's a big graphic. I left it on the platen for the final curing. After letting it cool for a moment I put it straight into the washing machine. When it finished, I took it out and it looked perfect! No change at all. I put it right back in the washing machine and am currently washing it for a second time. Thanks again. I feel much more confident about using my heat gun.
Okay, this isn't making any sense to me now... So very frustrating. Here's what's happened:
So far, I followed the guidelines/suggestions listed here by Cody. When I did the first test it worked fine as I posted, but now I'm finding there's no consistency.
Yesterday, I was screening a couple of shirts - black Ts with orange ink. I made a test print on another black tee that I messed up testing before, so I used the other side of it for this test run. I laid down two strokes, flashed it with the heat gun, then laid down one more stroke resulting in a very nice and crisp graphic. The graphic for the front of the shirt is roughly 10x10... After the final stroke, using the heat gun, I cured it. I went long on the curing time because I'm still a little paranoid about what works and what doesn't. I cured each section of the graphic for about 1 minute each. It took some time. As soon as I was finished, I let it cool on the platen. I decided to take the opportunity to do some more testing so I immediately threw the T into the wash to see how it would do. 20 minutes later, I checked it and there was no fading at all... No obvious change in anyway. So, I washed it again right away. 20 more minutes later I checked it and again, no change. I felt very confident in the curing time so I went ahead and printed the front of the black tees with the orange ink and cured them all the exact same way.
Next, I went to screen the back image which is a skinny ornate graphic that is 16 inches tall at it's highest point and 12 inches wide at it's widest point. It's like a really ornate "L". Did a test print - two strokes, flash cure with the heat gun, final stroke, full cure at 1 minute per section. Mind you, I am using the exact same ink. I let the test print cool, then threw it in the wash to see what would happen... 20 minutes later, I took it out and more than 50% of the graphic washed away!!! What?!? I don't get it. I did everything the same I thought but I came up with the exact opposite results. Very frustrating. I just can't afford to buy a flash dryer and from the looks of Cody's success with his company using mostly heat guns, I thought I could run with this for a while even if it meant taking a little longer per shirt. I am bugged now because I put a design up on my site announcing it would be available late in February and have received a handful of questions about the exact date and so on... It too is a large graphic so now I don't know. Any suggestions? Any thoughts? Anything would be helpful... Thanks
First, test the cure by stretching the print. If it cracks, its not cured.
Back in high school a friend and I printed shirts out of his garage. We couldn't afford a dryer so we built one out of plywood and three heat lamps. Print, remove shirt, place under lamps for ~3 minutes (for us) and it was cured. I often wondered if you could use an infrared heater instead, disable it's safety and mount it facing down.
Just a quick thought on the orange not curing. I am getting back into printing, but in my original foray, we had the hardest time getting orange ink to cure. Even more so than metallic silver or white. Also, orange is a weak color, especially on black. A white underlay on it might help. If nothing else it will help keep the black from bleeding through the orange as much. Something like one coat of white, two of orange, and then cure might help solve the situation.
Use a laser temp gun while you are applying heat from the gun to see what temperature you are at. I would probably go to about 320 - 340 If you are using plasitol inks.
i said so many times on this forum, that i believe i might appear like a person with an obsession: use a heat press to final cure the ink.
i use this method and no complaints so far, but i am only screen printing for 6 months.
it is a common method when a conveyor drier is to expensive, especially for a beginner, and it is used not only by beginners, but also by pros, in some parts of the world (south america, eastern europe etc).
so, flash the ink with the heat gun, put o piece of baking paper on top of the graphic and hit it at medium-high pressure for 20-25 seconds at 330 dregrees.
as orange color not curing, it may be this: when you flash the first layer, as you use a heat gun, you have no control of the process and you actually may be curing some parts of the desing, and the second plastisol layer won't adhere properly to cured ink.
for that, i bought a heat gun with digital heat control, and this helps me a lot.
If your using water based inks, can you simply air dry it and then put it in the heat press?
If so, how long would you have to air dry it for?
Another thing i have been wondering was when doing a multi-color print, do you dry and cure the first color you put on and then add the second color and dry and cure...and so on?
I only have a one color set up right now so this would probably be the only way i could do a multi-color.
So i know this thread is old but i was wondering how you built that dryer? Can you simply get those heat lamps at lowes or home depot?
Basically it was a big square box insulated with asbestos stove insulation and heated by three heat lamps with a short (6" or less) door on the bottom front. Our platens were designed so that we printed on the shirt and placed platen and all inside the oven which could hold 4+ shirts. It wasn't very pretty, nor efficient, but at the time we had never even heard of a conveyor dryer so it was the best we could do, it was inexpensive, and it worked. An oven thermometer showed the temperature. If I were going to build something like that again I would choose a better heat source. As mentioned, a heat press would also work and be more flexible, although slower.
Curing with Heat Gun Technique: Anyone? 
