Powder Top Coats Prevent Tarnish

How to Prevent Tarnish on Silver Finishes

Typically, one coat of powder is all that is needed. But, silver powder-coating finishes, including HotCoat's Argent Silver, Extreme Chrome and New Smoke Chrome need to be top-coated with a clear or translucent finish to protect them from tarnishing. For best durability, topcoat with Gloss Clear, or one of HotCoat's translucent colors. Only topcoat the completely cured base coats. The base coat will be thoroughly cured by leaving parts being coated in a 400°F oven for 15-20 minutes after flowout occurs.

Allow the part to cool before topcoating. It is normal for the topcoat to slightly diminish reflectivity. To minimize this loss, only apply enough topcoat to hide the color of the base. To prevent the Gloss Clear from yellowing, prop the oven door open about 1/4" while curing to enhance air circulation. If you're having trouble applying the topcoat, make sure that the ground clip is making direct contact with the metal part, that the emitter tip of the gun is clean, and that there is 1-1/2" to 2" of powder in the cup.

Top Coating

1. Thoroughly cure the first coat at 400°F for 15-20 minutes after flowout. (Flowout is when the powder turns from its dry state to a liquid, wet-looking state.) Note: Cure the Extreme Chrome powder for 20 minutes at 375°F after flowout to assure a complete cure and shiniest finish.

2. Once the timed cure is complete, turn off the oven, open the door, and allow the part to cool without disturbing it.

3. Once cool, remove the part from the oven and support it as you did for the first coat.

4. Load the gun about one-third full with the appropriate color or clear powder.

5. Attach the ground clip directly to a bare metal area on the part. You can do this by threading an old bolt into an existing hole, or simply scraping the powder from an inconspicuous area, and attaching the clip.

6. Apply the second coat in the same manner as the first, concentrating on the deep recessed areas first. After the part is thoroughly covered, disconnect the ground clip and give a light coating to the bare metal area. Cure as usual.

Feel free to email us with any applications for which you have used HotCoat