As I mentioned in the previous post, the powder coating process was mostly successful. The problem was that bubbles appeared on the bed surface.
I discussed possible causes of the bubbles with my husband, who has much more experience in powder coating than I do. He said it could be due to any number of reasons, including either porous metal or contaminants trapped in the metal. The air or contaminants (such as oil) trapped in the metal would start to expand as the metal is heated in the oven at temperatures up to the 400°F that is required to liquefy and cure the powder coating. The bubbles then form as the contaminants escape through the powder coating. However, he points out that this is all speculation on his part and the true cause remains unknown. All I know is that Ms. Rusty looks like she has a bad case of acne and I need to fix it!
I decided to use elbow grease to sand away the bubbles. My supplies for this task were found in the paint department of the local Home Depot. I bought a sanding block with 220 grit sand paper to knock down the big bumps and a 320 grit to smooth out the surface. I also picked up a bag of #000 steel wool to make the surface as smooth as possible.
After an hour of sanding the bed, all the bubbles were gone and the surface was as soft and smooth as a baby’s bottom. There are still little pock-marks were the bubbles were, but I don’t think it is possible to completely eliminate them without sanding down to the bare metal.
Because the bed now has a dull surface, I decided to apply a coat of clear Krylon Fusion (see previous post) to make everything nice and shiny before applying the decals. I taped off the bobbin area to avoid too much build up of paint which could make fitting the slide plates difficult.
The clear coat dried really fast (< an hour) and Ms. Rusty looks really pretty from a few feet away!
However, if you get closer, you can see where all the bubbles were on the bed. It isn’t pretty to look at, but the bed is really smooth so fabric will slide over the bed like butter on a hot griddle!
Ms. Rusty isn’t perfect, but I’m happy with the way things turned out so far. She looks much better than before. And more importantly, the metal is completely protected and rust-free, so she’s no longer at risk of rotting away, which was one of my main goals.
The next step step in the process is applying decals. That should be fun!!!