Think I may have just found the bigger problem. The block that mates with this surface has alot of wear on the outer edge. Trying to measure, it's around .0015" worn. (The area with all the grooves in the pic) So gonna take a good bit of sanding.

I'm kind of suprised it wore faster than the aluminum center section. How did that happen anyway???

Another idea I just had while checking the parts is after sanding everything smooth, maybe using fine valve lapping compound and place the block on the center section and work it back and forth to flatten any uneven spots.... ?

 

I dropped down to 220 grit emery from 500 after realizing it was gonna take forever to remove enough material to renew the surface. Going in figure 8s and rotating 1/4 turn every 10 cycles, using some wd40 also. After about 20 minutes it's pretty flat/clean now. Will finish with some fine grit later

 

Good luck. Usually, when you start with a pos, you wind up with a shinny pos.
They are disposable. Just my opinion.
But…… after you finish the cylinder block, I would lap it to the center section,
then into a US tank.

 

It is alot of work for a "maybe" (that is, the reassembly and installation. Re-surfacing the parts wasn't too bad)

But actually is looking pretty good so far. I had some medium grit lapping compound, and after sanding the block some more with 500 grit, sat it on top of the center section with some compound and worked it for just a couple minutes. (Just like lapping a valve) The wear pattern seems very even and consistent. In other words, flat. No hi or lo spots

I get what you're saying, but if the surfaces are both smooth and flat and match each other, should be close to just how it was new. This isn't some exotic material after all. It's steel and aluminum.

The finish turned out very matte with the lapping compound tho. Would like a shiny finish, but feel like it may work as-is. (But def gonna try to shine it up some more)

. Good tip about the US cleaner. I will do that unless someone else can talk me out of this madness 😁

 

Here's a long winded video of the process if anyone's interested. He said his worked after the procedure. I feel like his technique wasn't the best. Didn't lap it, but did finish it to a very fine grit. Then said he mixed 15-40 and gear oil to try to get 20-50 lol. But claimed success. He made like 5 or 6 parts to this. Watched bits and pieces. He had a great idea for a drain port on the non-serviceable zt-2200 (ezt)

 

Just ordered a diamond polishing compound kit. Hopefully will work for this. Not sure what grit the compound I have now is, but it's way too coarse. I think this diamond compound is used for polishing glass, but it has 450, 1000, 2000, and 3,000...and goes all the way to 80,000

 

The polishing compound came in quick. Spent a good bit of time this morning on it. Probably an hour going from 450, 1000, 2000,...all the way to 60,000! (Cleaning compound off well after each step) Maybe didn't work it hard enough, doing it by hand after all, because it's not mirror finish by any means. But maybe good enough. It's smooth and flat anyway.

Not really sure if the juice is worth the squeeze, for the center section anyway. The blocks are pretty easy to resurface, but the center section might be better to just replace with a new one. But it's a nice little experiment. We will see how it holds up. Got a seal kit ordered this morning. Will touch up the other surface and block as well