Removing corrosion from Mac SE/30 chassis and floppy cage

[krishnadraws]

I wanted to share some progress I made on the dilapidated Mac SE/30 I'm tinkering with. To remove the bulk of the corrosion on the parts, I submerged both the chassis and the floppy cage into a tub filled with Apple Cider Vinegar. Then I used Barkeeper's Friend to tackle some of the milder rust areas. Next steps are Paint / Primer and Clearcoat. 

 

[ktkm]

Nice! Is it better citric acid?

 

[krishnadraws]

I haven't tried citric acid - but I think, from what I've read, the acid eating properties are similar. Today I finished applying paint / primer to the chassis. It looks a lot better now.

 

[LaPorta]

Nice job! Evaporust is even easier!

 

[krishnadraws]

Thanks! I'll have to remember that for next time haha 

 

[krishnadraws]

I have everything ready to test, except for the Mac's original logic board, which I'm at an impasse on. Next weekend, I plan on taking the logic board out of a working Mac SE that I have and use it to test with this Mac.

 

[beachycove]

How long did it take?

 

[krishnadraws]

This was a weekend project, starting on Friday and ending Sunday afternoon. Spraying the paint on the chassis and HD/floppy cages and adding clear coat took about 4 hours (they were already dry by that point). 

 

[LaPorta]

What sort of clear did you use?

 

[beachycove]

Sorry, I only meant to ask how long it took to get the rust off in the cider vinegar. I suppose my question was, how effective an agent is it? I have an SE chassis that needs similar attention, so there is a reason for asking, especially as your "solution"  must be a good deal cheaper than a commercial de-ruster!  Impressive results, btw.

Given the timeline overall, it obviously took you hours rather than days or weeks. Overnight or some such thing?

 

[LaPorta]

I’d like to know too.

For Beachycove, id try Evaporust. I’m not a salesman, I’ve just had such good results. The product isn’t too expensive, and it is reusable. You just submerge the part you want de-rusted for about 12-24 hours, and it’s just gone. No scrubbing, no elbow grease. It’s effortless.

 

[LaPorta]

P.S. - what’s the logic board issue?

 

[jessenator]

These chassis/cage components are just nickel steel, right? Unless there's some crazy other components, one option might be to make an electrolysis tank—I do it with car parts like driveshafts, steering knuckles, and the like—it works wonders! Just don't do it if there's ANY COPPER or STAINLESS aspects of the parts—I know the whole isn't, but even if there's a small amount—doing that will release some nasty, carcinogenic **** you don't want to make.

The basics are best explained in this video:

Also, this process could be modified to re-plate the target part with zinc, but that isn't covered in this video, specifically.

Personally, what I'd do is remove the rust via electrolysis, give it a good clean with pure acetone or paint prep, and use a self-etching primer base, and then a Rustoleum chrome finish.

 

[krishnadraws]

What sort of clear did you use?

I used Rustoleum’s Clear coat spray. It works really well and dries within a half an hour. 

 

[krishnadraws]

P.S. - what’s the logic board issue?

Certain vias need to be wired up. I’ve repaired traces and installed new resistor packs and F258 chips. The ROM slot needs to be replaced. I feel it’s beyond my skill level. The ROM itself probably needs to be replaced. If anyone’s interested and has the ability to do these things to help bring this Mac back to life, I can ship the board out. 

 

[krishnadraws]

Sorry, I only meant to ask how long it took to get the rust off in the cider vinegar. I suppose my question was, how effective an agent is it? I have an SE chassis that needs similar attention, so there is a reason for asking, especially as your "solution"  must be a good deal cheaper than a commercial de-ruster!  Impressive results, btw.

Given the timeline overall, it obviously took you hours rather than days or weeks. Overnight or some such thing?

I used two applications of the Apple cider vinegar. The first application was left overnight from Friday to Saturday. The second application was left overnight from Saturday to Sunday. The first application took care of 80% of the rust. After removing the chassis from the cider, I used a wire brush to get to some of the harder to reach areas. Wire brush scrubbing was minimal on my part.

 

[krishnadraws]

Some follow-up on my dilapidated SE/30 project. I was able to successfully test the CRT, floppy drive, analog board, and PSU in the Mac SE/30 with a Mac SE FDHD logic board pulled from one of my other compact Macs. Sadly, the Quantum hard drive that came with the Mac is as dead as a door nail. 

There is some slight burn in on the top of the CRT (not sure if that's fixable), but it's not a deal breaker. The floppy took a few attempts to properly auto-eject. The first few times it was valiantly struggling to eject the disk. I used my tweezers to help it out. I did this a few times and finally the lubrication had worked its way through to eject the disks all by itself. 

I put everything back together again (after returning the SE board back to the computer I took it out of). So this Mac SE/30 will sit as is, until I can find a working SE/30 logic board for it.

I didn't think I would like the clear case with the beige back aesthetic, but seeing it all together, I really do think it looks good. It feels like a forerunner to the translucent iMac era.