Primarily worry about rust on the project IBM 1402 reader/punch
Table of Contents
Flora to Garner
From "Bill Flora" To: Robert B Garner Robert, I'm attaching some photos that I took on Friday. The primary concern I have is with the PUNCH feed. You can see from the close ups, that the stainless steel rollers are rusted. I'm not sure what I should use to try to get the rust off. Any Ideas?? Do I need to get approval before I try something. My first thought was use light oil on a soft cloth, and rub hard. There is also rust on the card hoppers, I won't touch any of that for now.
Garner to Flora
----- Original Message ----- From: Robert B Garner To: Bill Flora Cc: 1401 Restoration Team ; Bill, Regarding getting the rust off the 1401 card reader/punch surfaces (pictures below): the advantage of your suggestion of using a soft cloth is that it wouldn't change the roundness of any of the rollers or flatness of surfaces. But, we may need the greater abrasive power of a fine sand paper, say 320 or higher? One idea would be to mount the rollers on a lathe or drill and spin it while applying the sand paper. Flat surfaces would be another matter... (Another option is phosphoric acid, but it has the disadvantage that it may pit the surface?) I suspect we will want to remove the entire card path mechanism and give it to someone who specializes in restoring metal machinery. Let's start looking for references. We'll want the concensus of the team before we do anything. I've cc'd the team alias, including Arnold/Rolf, to get ideas or suggestions... - Robert
----- Original Message ----- From: Grant Saviers To: Robert B Garner Cc: Bill Flora ; 1401 Restoration Team All, In my experience with precision gages and rebuilding several machine tools is that superficial rust as shown in the photo feels and looks worse than it is functionally. Removing the debris and rust will leave small surface pits which are not likely to have much affect on the operation (except if they are in a sleeve bearing). 320 grit sandpaper is way too coarse, however. If the parts can be removed (best) then a very fine (000) steel wool, used way away from the mechanism and any electronic parts will usually clean up the part. I sometimes use WD40 as a cutting lubricant as it helps to cut residual grease and keeps the rust from clogging the steel wool. This is messy so wear nitrile or neoprene gloves (WD40 eats latex quickly). For flat parts, some 600 grit wet/dry paper can be used as a coarse lap, or we can get some 3M lapping film in much finer grades that can ceate a polished surface finish. I wouldn't use any power tools for the first pass cleaning. Oxided oils can be very tough to remove - parts look rusty but it is mostly oil and dirt. I use a hot solution of water and dishwasher detergent in an ultrasonic cleaner. There is probably a little etching of the surface, but cutting tools (end mills, slotting cutters, etc.) come out looking almost new and work fine after 10 minutes or so in the tank. If the part has to be cleaned in place, try a brass brush with WD40 and have lots of rags/wipes to collect the debris. Steel wool or abrasives used in place are very dangerous for the long haul. Keep the WD40 out of bearings if at all possible as it is really not a lubricant. If the rust is so bad that the part won't function after the above, then the choices are more complex and expensive - regrinding and shim to fit, resize and use new bearings to fit, plate nickel or chrome and grind to original size, plasma spray coat and grind to size, etc. Grant
----- Original Message ----- From: "Paul Pierce" To: "Robert B Garner" All, A very good treatment for this sort of equipment is the maroon 3M 7447 scrubbing pads wetted with a light lubricant and solvent such as light oil or kerosene. These pads are made for exactly this sort of work and are amazing on light rust such as in the photos, producing a nice smooth surface. They will dull highly polished surfaces such as chrome or nickel plate, but there is no alternative that will remove rust and magically restore the polish. They are available at industrial supply stores such as J & L Industrial. ( http://www.jlindustrial.com ) (see http://www.jlindustrial.com/catalog/product.jsp?id=SBH-04029J ) If there is a store in your area, you can get advice from the clerks (or better yet, the customers.) They do require considerable elbow grease. Probably the card paths should not be oily when you are done. Look in the service docs for places they say to avoid with oil. After cleaning the rust off, such surfaces can be degreased with a solvent such as lacquer thinner or a degreaser. However, its much safer to stay on the too oily side than to degrease much, which can ruin bearings. A little residual oil on surfaces is a good thing, it protects from further rust. I would clean these with a 3M pad and kerosene first, then when everything is as clean as you like go through and lubricate the machine according to the service docs, the kerosene will slightly degrease things. Find people who restore old cars etc. and see if you can get even better advice. Paul
From Dag Spicer Hi folks, Whenever you have material science related issues like this, would you mind copying Allison Akbay, (firstname.lastname@example.org)? She has much experience and extensive contacts with subject matter experts in this area. Also, she needs to approve any compounds used for restorative work before any work is undertaken. Any thoughts on this one Allison? Thank you, d.
From Allison Akbay A great resource for finding materials that are considered safe for restoration is the Conservation DistList Archives: http://palimpsest.stanford.edu/byform/mailing-lists/cdl/ There is a search option on the above page and when I searched for rust a large number of messages came up. One of interest is : http://palimpsest.stanford.edu/byform/mailing-lists/cdl/2000/0137.html The maroon 3M 7447 scrubbing pads may be appropriate but first it there needs to be a check done that whatever cleaner they contain is neutralized at the end of the process and doesn't keep eating away at the metal in the long term. They sound like ones that are used by jewelers to polish metal in which case they work by abrasion and are chemically neutral, fine as long as they are used in moderation since they actually remove the top layer of the metal. Allison
If parts can be brought to my shop in the east San Jose foothills, I have additional options:
Blast cabinet cleaning - I have three grits available - glass beads, silicon carbide & walnut shells. beads at low velocity do not change the dimensions, but do remove surface grime and rust. silicon carbide is more aggressive. walnut shells are the lightest cleaning and if abrasive residues are left they break down rather than act as ongoing grinding compound. I also have a large outside sandblaster if large parts need refinishing.
Blast Cabinet - front
Blast Cabinet - front detail
Blast Cabinet - open door
I have two small ultrasonic cleaners, one large one, and a kerosene parts washer.
A full machine shop (lathes, mills, grinders, inspection stuff, etc.) if parts need such.
Regarding the 3M Scotch Brite pads, I advise caution with the maroon pads as they range in grade from coarse to very fine. The white and gray pads are a better starting choice as they are ultra fine and super fine. See mscdirect.com for the choices (use their search engine). Again, I advise against using any abrasive materials in situ.
I also suspect that the parts in the 1402 are not stainless steel (if they were they would not rust). Certainly the punches and punch blocks (dies) are tool steel. I think a more common manufacturing approach circa 1960 would be to hard chrome plate wear (feed rollers, throat blocks, etc.) or corrosion susceptible parts. Electroless nickel plating was also common. Another choice would be to use a chrome cleaner, but as Allison points out the rust conversion chemicals will need to be neutralized and thoroughly rinsed away. Clean deionized or distilled water ultrasonics are very good for the final final rinse. The 3M pads are a polymer material with abrasives bonded to them, I doubt if there are any residuals other than abrasive particles.