by WOODWEB's Finishing Team:
John Buries and Bob Niemeyer
Q. We are a jobshop and have a project request for a plaque-sized piece of MDF covered with white primer vinyl with a glossy decal stuck to it. The goal is a high build wet-look gloss finish.
We have tried several different finishes, achieving the best results with an acrylic polyester 50% solids in two coats. This requires 24 hours at 90 degrees for each coat. A faster turn time is desired.
We have looked at UV coatings but can not find one that is clear enough. Waterborns don't adhere to the glossy decal. Laquers appear clear in the can but discolor the white surface when applied. Is coil coating of any interest to us?
A. Bob Niemeyer responds: I suggest you use an acrylic urethane system. This will give you a true water white finish with no color shift. Also gloss urethanes give a 90+ sheen right off the gun.
You may need to use a Barrier sealer (isolating agent) before applying your topcoats due to the different substrates involved. Always pre-test your system first! If you don't have a source for these products try calling ICA Wood coatings at 616-682-9115. Ask for Tim Klinfelter and explain your problem to him in further detail. If you run into a dead end contact me at niemeyer@itis.com or at 414-246-6555.
