More puttering today. The battery came back after a night on the charger and I measured dark current at 1.6 mA, which is actually considerably less than an NA Miata should have. So the battery discharge is a mystery. It's running an ND wet cell take-out battery that dates from 2017 or so, so maybe the battery just failed. I'll keep an eye on it.
I realized that the wiper airfoil was looking pretty sandblasted.
So I took it off, stuck it in the sandblaster, sanded it and gave it some fresh semi-gloss paint. Much better, although now I have to remove the wiper arms and do them. And no, I don't know what the effect of running without it would be, my 1994 never had one.
When I was at work on Thursday, I picked up a stock exhaust manifold to work on. It happened to have a good looking heatshield with very minor cracks so that's in place while I tinker. I might just leave it like this.
Meanwhile, I took the other manifold and cleaned it up in the bead blaster and with some sandpaper. And it turns out they're black from the factory! Dunno what that coating is, but it's pretty tenacious. Here it is with the heat shield bosses removed.
Here's a picture of a new one. So it's more like bluing and less like an applied coating.
I'd been wondering what color to paint it, and it appears it should be black. I did not have black header paint in my cupboard. So I took the excuse to go for a drive and enjoy the growly noises, arriving back home right before some snow blew in. And here we go, matte black. I would have preferred gloss but it's not like I keep the engine bay in showroom condition. It'll look better than surface rust.
The lighting makes it look grey (it's for a Canadian car, so it's grey. If it were a US car, it would be gray) but it's a pure black in real life. And FYI, the rattle can developed a problem with the nozzle not shutting off. I would consider this can to be a single-use design that will not survive future storage. At least it worked long enough for the recommended three coats. Now I have to let it dry for a week, then there's a curing process. No worries, it's not like this prevents me from driving the car!
It's not the sexiest header, but is it better than the heatshield?