Q. My company makes metal giftware. We are applying decorative designs by hand and they are not very durable. I read your article in Products Finishing in regards to using polyesters as dye sublimation coatings. Can you advise me of suppliers of these coatings? In the article you mentioned that most craft stores should carry them. I’m sorry, but the mom and pop craft stores in my neighborhood don’t carry anything of the sort. I thought I would have better luck at a big box store or a paint store, but as you know, they’ve got tons of products for different purposes and none of them is specifically sold for dye sublimation transfer. I would appreciate a little bit of more precise information. Any help would be appreciated.
I’ve read your article and others that recommend two-part coatings such as polyester/acrylic plus a hardener to be used as a dye sublimation coating. Can I use a coating that is a one-package polyester/acrylic that does not need a hardener? Can I use a water-based coating? Have you tried these, and do they work as well? We want to use this coating over metal. Is that a problem? D.C.
A. The answer to your questions are as follows:
1) There are several suppliers of clear polyester coatings. Since the market for dye sublimation coatings is rather small, you would be hard pressed to find materials specifically sold for that purpose. It is the policy of Coating Clinic to not give specific supplier names. As I answered others on the same subject in the past, I suggest you use a two-component polyester as a dye sublimation coating. It can be 100% solids, provided the viscosity is low enough to apply with your painting equipment. You also must use a wax-free polyester coating. Some polyesters suffer from air inhibition when curing, and wax is added to their formulation to exclude oxygen from their surfaces. Suppliers of two-component polyesters are listed on pfonline.com under Coatings, plural-component. In many cases, the polyester coatings are also available at paint stores. When you contact those suppliers, speak to the industrial or high performance coatings people. You may even try automotive supply stores.
2) I don’t recommend using single-package polyesters, which are often modified with drying oils. We used to call them alkyds.
3) For your application, you probably cannot use a waterborne coating because the solubilizer in the formulation may interfere with the dye sublimation process. I haven’t tried them because I don’t decorate anything but my model railroad.
4) If the polyester is applied to metal, you may need a corrosion-resistant primer to protect the substrate.