Then it was time to mask and spray. I chose black for the hot turbine parts and red for the compressor. There's not much choice in this temperature range anyway, and these colors should look suitably Victorian. Two light coats and then one medium coat all done within the recommended one hour max, and then into the kiln for a three stage cure at 250, 400, and 600F with a 30 minute soak and cool down between each heat. That red sure looks bright right after painting.
Next step was to rig a method of holding the flange to the turbine scroll for welding. I used a scrap of 1/4" plate for a base and then wired everything in place, engraving a groove around the scroll case where it contacts the flange so I can relocate it precisely in case something moves. John Branje, our local expert welder, will attempt to MIG these pieces together using a nickel filler and by peening the welds between passes. Before that I will pre-heat the parts to about 800F in the kiln so there's less risk of heat shock (which can crack the iron casting or weld), and then post-weld slowly cool the parts in the kiln for the same reason. As you can see from my set-up, it'll be easy to lift the parts out of the kiln and onto a ceramic fibre sheet using a long steel rod inserted through the scroll case. One of the benefits of working with kiln-formed glass is I have refractory materials just lying around!
If it all holds together, I'll clean up and paint the scroll case black as well.
The turbo rebuild kit arrived today. All the parts appear to be of high quality and fit perfectly. As a bonus, the replacement o-rings smell like cinnamon oil. Given the kit cost only $78 delivered from Amazon, I should've bought it long ago and just moved on with the project. It's exciting to see this crappy old turbo start to show some promise here! Fingers crossed that by the end of the weekend I can have it all back together and ready to plumb for oil pressure. Then the project really begins.