In settings on your heat press, small details can make a big difference. For instance, the recommended application temperature for applying HotMark thermal transfer film is 320 – 340 degrees. Is that Fahrenheit or Celsius? What’s the difference? Only about 300 degrees. 320 degrees Celsius is over 600°F. Getting that detail wrong can melt your film and turn a white shirt a crispy golden brown. Such was the case this week when a customer posted to us that their HotMark was melting on their heat press. After some head scratching, one of our alert customers advised the user to check to see if the press was set on Fahrenheit or Celsius. Sure enough, the press had been changed to Celsius, so when it was set to 340°, it was actually at 644°F. That is indeed hot enough to melt HotMARK, Nylon, polyester, Lycra, and many other polymers.
This is a fairly unusual situation because all Geo Knight and Stahl’s heat presses are made in the USA and set to Fahrenheit as the default. So unless someone has changed the menu, this won’t happen in your shop. If you’re not sure, just check the LCD control panel. It will display a small C or F next to the temperature so you know if the readout is in Fahrenheit or Celsius. (Fig. 1) If for some reason, you need to reset your press to the factory default, it’s pretty easy to do.
On a Digital Knight just press the Temp and PRG buttons simultaneously to enter the Options Menu. The first screen in the menu is the Fahrenheit or Celsius Option. (Fig. 2) Options are selected using the up and down arrows. Press the ‘up’ arrow on the left to select Fahrenheit; or the ‘down’ arrow on the right for Celsius is you’re of the Metric persuasion. Then simply push the PRG button to cycle through the other screens and out of the Options menu. That will ensure that you don’t get 640° when you want 320.
Of course, there are other silly ways to mess up a t-shirt. The mistake I make most frequently is forgetting to reverse the design before cutting. Occasionally I’ll finish weeding a graphic and realize as I start to place it on the garment that I forgot to mirror it. D’OH! Start over! And there are some who say they’ve seen me put Siser EasyWeed on a shirt upside down so that it stuck to the Teflon sheet instead of the garment, but that’s just an unsubstantiated rumor. That’s my story and I’m sticking to it. We all make silly mistakes. Sometimes we can learn from them.
