• Please review our updated Terms and Rules here

This is some of the worst Rust Damage I've seen....

If I can get the rust at least removed down close to the metal then I can treat it with an automotive rust product that will seal the rust in prevent it from spreading, I will then seal it with something so it won't have a problem going forward. So far, we have been soaking in a distilled white vinegar bath overnight and the back is completely clear of rust and the top of the sheet is significantly lessened. There is still a good deal of sheet metal left under the rust and there aren't any holes through the sheet where there shouldn't be as far as I can see. A few more hours and it should be ready to neutralize with baking soda, then treat, and seal. Here's hoping.

-Edit- This is after I have finished the bath on the top and bottom shells. They are much better, but not perfect. I don't think I can get them any better with vinegar. I might be able to sand the rest of the rust down, but I cannot be certain. Here are some pictures -

IMG_20150927_134823840[1].jpgIMG_20150927_134807168[1].jpgIMG_20150927_134811631[1].jpg


What do you guys think? Keep going or seal and deal? It's significantly better than it was, that's for certain.
 
Last edited:
If I had something like that that I wanted to salvage, I'd put a flap wheel (maybe 120 grit) on my buffer and clean it up. They do make flap wheels that can be chucked into a standard jacobs chuck (i.e. for cordless/line powered drill or drill press). If you have one of the 3M rubber finishing wheels, that would be the final touch.

flap244D.jpg


Another option might be a not-too-coarse scratch brush.
 
Whoa! If it was me I'd try to find another case. Wouldn't EVEN want to keep that case. Can't quite tell from the pics, but the case looks ROUGH!

I know you know this, but I would clean the system board as carefully as possible and try to run it outside that corroded case. Put it on a sturdy cardboard box and try it. Sounds like you don't have too much to lose with it. Gosh I have a 486dx-4 I just finished building on cardboard box right this minute running. It was REAL cheap and caked with dust, grime and whatever. I just used 91% alcohol with felt tip swabs to clean it then I took more swabs and went back over it with distilled water. Actually I've done this for quite some time with old vintage stuff. Don't know if this is the best way or if it could possibly cause damage, but I've been successful every time. I don't exactly soak it the boards either; very conservative. A few days ago I received a VLB video card and it didn't work on first test: colors changed/flashed on the monitor and no text was displayed; after using the way I clean PCBs it now works like a charm. I know there are a LOT more experts on this site than I, but this works for me. Of course I let the PCBs dry for a few days too.

I think I've seen empty cases for the HX and EX before on ebay.
 
Sorry but I have to disagree. If the seller didn't show pics of the whole unit then he misrepresented the item. I buy items many times "as is" but with enough pics to help me decide. It's just not right to NOT post all angles of an old computer esp. if the seller knows some sides are corroded.

I would however first send the seller an email before posting bad feedback.
 
I have been conversing with the seller. The item is guaranteed through them for 14 days after arrival. I asked my questions, got the answers to them and I am satisfied. I let him know I wouldn't be giving a 5 star rating for the item description and he stated he understood. Everything else from the seller has been top notch. They responded more quickly than some sellers do and they offered multiple things, including partial refunds, which I refused. I don't want nor expect a refund of any type or any other form of remuneration be it additional items or a refund on shipping.

I took the power supply to my engineer friend and he laughed and said we could rebuild the wire wound part really quickly. I keep forgetting the name. You would think as many times as I have heard it I would remember. I cut a sheet of I think it is mylar plastic like the material used to insulate Amiga motherboards and placed that between the remaining rust and the board and put everything together to test. Aside from some issues with the CGA output, the machine works very well.

It has the memory expansion card in it populated to bring the machine to at least 640K. It may be more, but the cards that increased the total memory to 768K indicate they have some sort of driver that has to be used? So I don't really know. I do know this though, I need to get images of the system disks so I can check the EEPROM settings. It seems to be running really slow.

@Chuck(G) - I like the idea of that device. I will have to find one. Amazingly as far as I can tell, the rust did not eat entirely through the metal sheet, so it is completely salvageable like you said. Thanks again to everyone for their help here. I have the motherboard yet to clean as there are a couple spots of dried water, and a few solder points have rust on them. I thought I would remove those and just resolder those pth.
 
You can probably find flap sanding wheels on any big-box home improvement store or even Wal-Mart. As with any power tool that spins, wear eye protection. You don't want grit and/or rust in your eyes.

Another option is if you have one of the oscillating tools, such as this very inexpensive one from Harbor Freight:

image_22516.jpg


You can use the triangular sanding pads to get into the nooks and crannies. As cheap as this tool is, it's saved my bacon more than a couple of times. I've used one to do blind cuts into wood where almost nothing else would have worked. Wish I had one 30 years ago...
 
toroidal transformer?

Yay, a working Tandy 1000. My *very* first computer (which I returned). It seemed buggy. I got the 1985 1000$ special w/monitor, upgraded the monitor, was around 1300$. Even the upgraded monitor was horrible to look at. I started reading Byte magazine (I guess I hadn't prior to purchasing it) then started pricing things, and learned I could get a much better quality package for the same or less (including a Princetion Graphics monitor). Didn't buy another computer for about a year and a half (A TANDY 2000!!!). The screen situation vastly improved, but compatibility all went to heck. I didn't purchase a CM-1 or VM-1, but rather splurged and spent 600$ on a Multisync II. I had to take a 2nd job in order to buy it. I guarded Christmas trees for 3 weeks, in an area of Long Island that wasn't so comfortable to be in between 11 and 7am. 1987.

I remember typing in a binary tree program from the pages of Creative Computing (into the T1000 while I still had it). Not a data construct, but a binary _tree_ that sprouted branches and leaves. Mine was a little cockeyed LOL. It worked, but was somewhat anemic as trees go.

I just hate proprietary components. Even the Tandy 1000 had at least 1 (the 2000 had none, but used an off the wall little known vendor's graphic chips). I hate that! I think that's what prompted me to toss 3 Tandy 1000s a few years back. It was stupid in retrospect. They were rusted up pretty good too, but were salvageable. Oh well.
 
But almost every machine of the time was proprietary in some form. You have the PCjr., with the proprietary bus for expansion, then the PS/2 with MCA,all in an attempt to stop clone machines, then the Amiga and the Atari were taken to the extremes in proprietary systems. Let's not forget all of the 8-bit micros. Any machine with a custom audio or video chip can qualify for proprietary. Apple Macintosh machines with their PDS sockets, ADB system among other things are proprietary as well. It's kind of a fact of the industry at the time. To dislike all machines that had proprietary hardware in them meant that your pool of products to purchase was greatly reduced.
 
But almost every machine of the time was proprietary in some form. You have the PCjr., with the proprietary bus for expansion, then the PS/2 with MCA,all in an attempt to stop clone machines, then the Amiga and the Atari were taken to the extremes in proprietary systems. Let's not forget all of the 8-bit micros. Any machine with a custom audio or video chip can qualify for proprietary. Apple Macintosh machines with their PDS sockets, ADB system among other things are proprietary as well. It's kind of a fact of the industry at the time. To dislike all machines that had proprietary hardware in them meant that your pool of products to purchase was greatly reduced.

Yes and no, but I disagree w/the rest of your statement. Many many z80,80x86, eh not too many 68k used stock stuff. The issue is if I can't find the parts to repair a machine, that puts a big frown on my face. Yes there are uber cool machines that have loads of proprietary stuff (Atari STs namely). But basically most of what I have has virtually no ASICs or what have you. It just stinks, unless you're willing to brew your own hardware, which I am *not* opposed to (but who generally has the time). It's fascinating to recreate chips of course. This actually is a big interest of mine, for alas there will come a day where EVERYTHING will be unobtainium.

The Mindset has custom graphics and sound chips. I went looking for info from the creators years ago. They clearly were concerned with protecting their ancient property rights, and asked that I address these matters in a letter, which I did LOL. So stupid. What could be that old and that ground breaking, in a day where graphics cards have 1000 times the level of integration, and are in fact more powerful then the cpu's that host them. Double dutch bags. Now I may persue recreating the functionality of these chips eventually, but using a "clean room" approach - gathering as much info about, primarily, other Atari stuff, and working to understand what makes them tick under their gold plated hoods (and I recently cracked open my original Mindset II and learned or remember that they weren't run of the mill epoxy coated chips). I realize this stuff was indeed extremely innovative in it's day . . but that was 1983!!! You cannot tell me that in this day and age such a thing is impossible, with all the texts and knowledge available. I think it was Allison on the other list who tipped me off, when I inquired about the NEC 7220 graphics chip. "These are very well documented ic's". To me there seemed to be a lot of meaning unintentionally hidden in that statement. Now whether there is or she actually meant actual diagrams of the chips innards are available I don't know. But learning to duplicate a chips functionality apart from actual knowledge or it's innards is how I took it.

There were at least 2 articles in Circuit Cellar over the years, one on creating FPGAs of an RCA 1802 IIRC, and another on duplicating stuff inside an HP 41CV calculator.
 
Back
Top