Ignorance is bliss or something like that.
My name is Sandi Sturgeon and I am the owner of Steel Tattoos & Body Paint. I do custom powder coating, airbrushing, and hand engraving mainly for the motorcycle and automotive sector. But I will work on anything if it fits in my paint booth and powder coating oven.
I was contacted by an individual who runs a foundry to see if I would be interested in “chrome” powder coating 5 cast aluminium dragons. The castings were 3′ long by 2′ wide by 2 ½’ feet tall. I was told there might be some finishing to do on the castings in my shop to get them ready for powder coating. I agreed to the job and in a short while the dragons arrived.
A bit of finishing was an understatement. The castings were full of holes, porosity and in some places entire sections of the design were missing.
There was no way the castings could be finished by welding and grinding to keep the final cost reasonable.
Back to the first sentence, Ignorance is bliss…” I had no idea what I was going to do to bring these castings back to a finished state that the end client would be happy with. It occurred to me that I used “Aves studio’s Apoxie Sculpt” for a lot of my own sculpture and design work on bikes and wondered if it would work on the castings. I had never powder coated over this product and had no idea if it would work. Since we started the project on a late Saturday afternoon, I never bothered to contact Aves studio to see if the product would work figuring they would be closed for the weekend.
Powder coating involves oven temperatures up to 400 degrees on the piece being covered. I ran a sample of the mixed and cured Apoxie to see how it held up. I sculpted a life size molar tooth and baked it at 400 degrees then 500 degrees 4 or 5 times. The tooth turned brown and black in the oven but other than that it held up perfectly. I had 4 different men try to break the tooth roots off and no one could budge it. Perfect, I was convinced it would work.
We started to fill all the holes and porosity with the Apoxie Sculpt and then baked the castings at 400 degrees. The Apoxie held together perfectly. We then re sculpted the details and pieces that were missing and baked the castings again. Again the Apoxie held together perfectly. At this point the finishing and sanding of the pieces began. It was a bonus actually that the Apoxie turned brown from being baked as it made it a lot easier to see the areas it was applied for finishing.
The next step was to apply the first coat of powder. I used a medium dark grey as my “primer”. The areas where the Apoxie was applied didn’t want to take the powder on the first pass. I baked the pieces at 400 degrees to set the powder coat. Again it was a bit of a blessing that the powder didn’t cover the Apoxied areas on the first coat. The castings being such poor quality out gassed bad and there were thousands of air bubbles in the primer coat. Each dragon was surface sanded down completely again to get rid of the bubbles and the final blending was achieved on the Apoxied areas. Any holes left over were patched with Apoxie and blended in.
Another coat of powder was applied but this time I heated the castings to 300 degrees and hot coated them with the primer color. The powder flowed beautifully over the entire surface including the Apoxied areas. Once again there were just a few minor bubbles that were easily sanded out or filled, one more hot coat of primer and the sculptures were ready for the final chrome and clear coat.
The chrome coat was applied at 300 degrees and baked at 400 degrees. The pieces were allowed to cool, the surface checked and then reheated to 275 degrees, clear coated and then the final bake.
The pieces came out perfect. What started out as a total disaster was rescued by Apoxie. I am beyond a big fan of Apoxie now. All the other 2 part products you can by at the local hardware store in my shop have hit the garbage can and I only use Aves studio products in my shop for everything.
Steel Tattoos & Body Paint