Sometimes a little trial and error with cleaning can lead to a bonehead move. Case in point was to clean the original smog trees which in all fairness were fairly decent, to begin with. Further to that, I would have said they previously fit the bill of survivor condition. Until I screwed that up. I thought the evapo-rust being as mild as it is would simply clean them up a touch, but dunking them in there even for a short period was a big mistake. In a matter of about 20 minutes it leveled the original coating and they came out looking bare without any original coating. Like the copperish colored base or what was left of it simply wiped right off of them. This was just before MCACN and I was pretty choked at myself for not leaving those alone.
Since then I have tried finding someone who could reapply the phosphate coating and really never found anyone who could replace the factory-like finish. I read some posts about dunking them in a phosphate solution, and that others had painted them black with some phosphate spray paint but decided to try something else and see what brown colors I could find. Enter Stove Bright high temp primer and paint. I found this reddish metallic primer rated for 1200 degrees and then paired that with a can of Bark Brown which looked close to the original copper-like tone. Ordered them from Amazon in late December and they finally showed up about 5 weeks later. Needless to say, I prepped the tubes and today I put a couple of coats of the red primer on them before hitting them with the bark brown. It isn't exactly copper colored but I sure like the low luster satin finish they now have after a couple of coats of this high temp paint.
With the engine already having been rebuilt and painted by others, I'm planning to tumble the exhaust manifolds next week and get them looking more factory-like. With that now in the works, the smog trees should look right at home when the engine bay is all back together in a few short weeks. Once I put some heat through them I'll see how they blend in I suppose?
Note to self, evapo-rust and original smog trees do not mix. That original finish is quite delicate and does not play well with chemicals. Now, if you ever want to repaint a set of smog trees...here's what I ended up finding through Amazon. IMHO, the results are not too bad, in spite of my previous lack of judgment. (lol) Here's the stuff...
The high temp primer and the brown paint I used to refinish the trees.
Here's how they looked after dunking them in Evapo-Rust (big no-no)
And here they are after being refinished. Hoping these fade a touch after some heat cycling. The paint was fresh here and they have darkened up some more since drying.