cleaning rusted/ pocked hyd. cylinder rods?

[pybyr]

Hello all-
I'm doing some work on an older tractor loader that's been out in the weather with the hydraulic cylinders extended/ exposed, and they've developed some rusty "acne" - spots here and there rather than a coat of rust, but the spots (even though small) have raised/ rough texture.

Obviously if they're run back "in" with the abrasive rust, it'll ruin the seals, and quickly.
I realize that the "right" way to do this would be to get the rods re-plated or, apparently, replaced with new... but that isn't in the budget for this project right now.

I'd appreciate any tips and techniques of how to properly, quickly, and effectively clean off the raised/ abrasive rust particles without further damaging the surrounding/ intact hard chrome.
Thanks in advance for the help.

 

[jharkin]

Thats a tricky one....

Traditional route would be to try and mask off every single spot, carefully sand away the rust, then remove the mask and blend the repair in by buffing down from 600 grit to 1000, steel wool, etc and then maybe buffing it smooth with compound. Problem is where you had rust before you now have microscopic depressions that might result in tiny leak. Not to mention I have no idea what polishing out the rust like that will do to the surrounding plating.

Another thought is to use a chemical rust neutralizer (like auto body "rust fix" primers) and then try to strip the resulting coating with acetone or other strong solvents. Then buff as above. This is just a wild guess and you would have to experiment, Ive never tried it (well I have used rust fix primer on old cars, it works so-so).

In either case the rust is only going to come back on the now exposed spots eventually, so I suspect this is only buying you time.

 

[Ashful]

Electrolysis. Simple, easy, and will remove any rust with zero damage. Then buff back up with steel wool, pop new seals in those cylinders while you're at it, and that's about as good as it's going to get, without replacing the rods. If there's pitting, you're just going to have to live with a little leakage, but at least you won't be tearing up the seals.

Starter kit for electrolysis:

- 1 box arm and hammer washing soda (1 cup per 15 gallons water)
- 1 old-school battery charger (no smart chargers, no battery tenders)
- some rebar
- enough ground rod clamps to connect wire to each piece of rebar
- some bare wire, I prefer the stuff used to hang drop ceilings (cheap)
- a vessel large enough to hold the item to be de-rusted, with some rebar arranged around it (not touching)

For cylinder rods, I'd use a 55-gallon plastic drum (free from car wash), or build a box of suitable size and line with 6-mil polyethelene drop cloth. I can guide you on the particulars, if you go this route.

 

[jharkin]

Just ignore what I said
.... Jofuls idea is your ticket.

 

[pybyr]

Thanks for the suggestion of electrolysis- I am familiar with the concept/ chemistry, at least with simple single metal situations. Have you done it with chrome over steel like this situation? Some googling revealed mixed info about electrolysis of chromed steel. Is the item being repaired (the chromed steel rod) the + or the minus in your method

 

[Ashful]

Yeah, I'm no chemical engineer, so I've always just taken my chances with plated parts. So far, no regrets, but I can't tell you for sure what to expect. You better do a little reading and digging. A great resource for this, and where I learned most of what I know about electrolysis, is the forum at owwm.org.

I put everything except aluminum in the bath, and so far have had zero issues.

Again, if you decide to go this route, we can discuss more specifics (anode wiring and placement, cathode (good part) placement and hanging, etc.). Expect to let a lightly rusted part in the tank for 3 days, or a badly rusted part upwards of a week. The electrolysis will remove rust, paint, grease... just about anything not conductive.

 

[salecker]

Hi Pybyr
You said it was an old tractor.
Get some rolls of emery cloth,fine grits and some polishing oil,or WD40.Wet with oil and with a piece of emery cloth start polishing.If you really want a smooth finish use crocus cloth as the final polish grit,probably wouldn't rust for yrs.
If it was a new expensive tractor,you could go the expensive way.
Thomas

 

[Ashful]

Electrolysis ain't expensive. Here's the rolling table from an Oliver table saw, for reference.

Before:


After:


Note, this works quite well on large items:


I'm not sure if this is what salecker was referring to as "the expensive method," but I can assure you it's not. A few cents worth of electricity, a few cups of Arm and Hammer washing soda, and a bit of scrap metal (or rebar) is all it takes. Probably costs less than his WD-40 and emery cloth... and certainly does a nicer job. Once I fired up my first tank, I kept finding other stuff I wanted to stick in it, as the tank does all the work for you.

 

[pybyr]

Yeah, I'm no chemical engineer, so I've always just taken my chances with plated parts. So far, no regrets, but I can't tell you for sure what to expect. You better do a little reading and digging. A great resource for this, and where I learned most of what I know about electrolysis, is the forum at owwm.org.

I put everything except aluminum in the bath, and so far have had zero issues.

Again, if you decide to go this route, we can discuss more specifics (anode wiring and placement, cathode (good part) placement and hanging, etc.). Expect to let a lightly rusted part in the tank for 3 days, or a badly rusted part upwards of a week. The electrolysis will remove rust, paint, grease... just about anything not conductive.

Even if I don't end up using the electrolysis for the loader cylinders, you've peaked my interest for other projects (and I have a barn and cellar full of old metal projects of all shapes and sizes), so please tell me more

 

[Ashful]

We started writing a wiki on electrolysis over at owwm.org, so Google that up for starters. I could write a book on the subject, and I'm only an amateur. It will be easier to answer specific questions, we we see the part to be cleaned. I'll try to post some other photos of my various electrolysis rigs when I'm at home this evening.

 

[jeffesonm]

I've also had great luck using electrolysis to clean cast iron pans, a bunch of rusty old woodworking clamps, pretty much anything metal and rusty. I'm about to find myself a kiddie pool and do the rusty 48" mower deck I'm restoring.

You've probably got everything you need lying around there somewhere.... give it a shot. Once you try it you'll be looking all over for rusty stuff to de-rust


Joful - any other suggestions for containers for my mower deck?

 

[Ashful]

Joful - any other suggestions for containers for my mower deck?

Yes! Get some plywood, 2x4's, and 6-mil polyethelene, and build yourself a tank like the one I showed above! I've built a few tanks, and it's always the best / easiest way to go, for big stuff like that. I know one guy who built a tank large enough to do his flatbed pickup.

Here's how I generally do small stuff. Those scraps of plate steel hanging from the edge are the sacrificial anode. The parts being cleaned are hanging from the copper wires suspended by the scrap of 1x3 lumber (I use a copper pipe instead of the lumber, and rebar in place of the plate steel, these days). I still use that same trash can, 32 gallon.



Here's how I did some longer parts, one time. Rebar is sacrificial anode, good parts are hanging from the copper pipes. Note that all anode wiring must be made OUTSIDE of the bath, which is why I always bend the rebar/anodes to make connection above the water line. Cathode (part to be cleaned) wiring can be used below the water line.



I thought I had some photos of some of the large tanks I had made for doing a floor standing drill press or big bandsaw wheels, but can't find them now! Basic proceedure is to build the box, lay in the sheeting, put a few inches of water in the box, get the plastic sheeting arranged more nicely (staple perimeter above water line), fill the box, carefully set something in to support your parts and anodes (without tearing plastic), and you're good to go!

Electrolysis is mostly a line-of-sight process. Parts that are not line of sight will eventually get clean, but they take much, much longer. So, it's best to arrange an array of anodes that will give you line of sight coverage to your entire assembly. The trade-off is that you cannot exceed the current draw capacity of your battery charger, so if you use the typical 10 amp charger, you're usually looking at roughly 3 - 4 pieces of rebar, 3 feet long each, before you're at the charger's limit. You can parallel multiple chargers, though (keep anodes in separate clusters, tie all cathodes together on part to be cleaned), or go to a bigger charger (just be careful to not kill yourself). I have seen stories of people experimenting with DC stick welders, but I would not advise this.

Also, be damn sure you maintain a good anode, as well as a good connection to the part to be cleaned. I have seen stories of a anode connection failing, and then the most poorly-connected part of the anode behaving as the cathode (bye-bye good parts!).

 

[jeffesonm]

Thanks for all the info. On the charger itself, I'm guessing bigger is better? There is a 40/2 charger (with 160 amp starting) for sale near me... will more amps speed up the process or just allow you to use more anodes?

 

[jeffesonm]

Also Trevor as to you question about chrome, I was reading about electrolysis rust removal on another site and someone reported it not taking off the chrome, for whatever that's worth..... http://bbs.homeshopmachinist.net/th...ic-Rust-Removal-Get-it-done-in-2-hours!/page4

 

[salecker]

Electrolysis ain't expensive. Here's the rolling table from an Oliver table saw, for reference.

Before:
View attachment 109054

After:
View attachment 109053

Note, this works quite well on large items:
View attachment 109052 View attachment 109051

I'm not sure if this is what salecker was referring to as "the expensive method," but I can assure you it's not.
Hi Joful
I was referring to taking the cylinders apart and re chroming and repacking as the expensive route.Unless you were planing on using the tractor every day,or didn't have anything better to do.Removing the cylinders,taking them apart to do the electrolysis is a lot of work.The emery cloth/crocus cloth and oil will only take a few minuets and last a long time.
Thomas

 

[Ashful]

I was referring to taking the cylinders apart and re chroming and repacking as the expensive route.Unless you were planing on using the tractor every day,or didn't have anything better to do.Removing the cylinders,taking them apart to do the electrolysis is a lot of work.The emery cloth/crocus cloth and oil will only take a few minuets and last a long time.

Agreed. I had assumed they were already leaking, though, and that taking them apart for a seal swap was a given.

Thanks for all the info. On the charger itself, I'm guessing bigger is better? There is a 40/2 charger (with 160 amp starting) for sale near me... will more amps speed up the process or just allow you to use more anodes?

A bigger charger allows you to place more anodes closer to the object being cleaned, so in that sense, it will speed the process along a bit. Particularly on a large object, where you're sometimes forced to move just a few anodes around over a week or two, to get the job done with a smaller charger. Careful, though... some of the bigger chargers have "smart" circuitry in them, which requires the charger to see a battery across it, before it will deliver current. There are some guys I've seen using these, with a spare car battery connected across it, but that scares the chit out of me. There is a very high potential for accidental short circuits from time to time, as you move anodes and your part around, so be damn sure you have that car battery well away from the water, and a 40A fuse downstream of it, if you go that route. I don't think it's worth the risk, and have always stuck to my good old-fashioned "dumb" 10A charger.

The actual current is dictated by the cleanliness of your part and anodes, surface area divided by distance between anode and cathode, and the chemical consistency of your bath. 1/3 cup of washing soda per 5 gallons of water just about saturates the bath, more will usually not yield higher current, but less will lead to lower current.

 

[jeffesonm]

Well I went ahead and picked up the 40 amp charger... will be nice to do the stripped down mower deck with the big one while I do some smaller parts with the 10 amp. I've got some business travel eating up my schedule but in another week or two I'll build a box big enough to fit the mower deck and give that a go. I read you can also use lye in place of washing soda, correct? I happen to have some around from a bagel making project....

 

[Ashful]

I have read of others using lye, and it does supposedly speed the paint removal part of the process, but I do not know the recommended mix for lye. I've also read many warnings against using it, due to handling concerns. I really know nothing about it, but a quick search on the forums at owwm.org will probably get you some answers on that.

Figure you want to keep those sacrificial anodes (rebar) at least 4" away from that mower deck, on all sides. Size the box accordingly. Anodes below can set on firring strips, to protect the poly sheeting. Anodes above can sit on scraps of 2 x 4 stood on edge. Anodes around the perimeter can be hung from the edge of the box. Just remember, all of your anodes must extend above the water line, to make the wiring connection. Any anode wiring run below the water line will be eaten thru in short order, thus creating a potentially bad situation for your part(s) being cleaned. It's fine to run the cathode wiring below the water line, to the part being cleaned, as that wire doesn't get eaten in the process. I prefer ground rod connectors for connecting the wiring to the rebar, as it's easy to remove and re-install, for the daily cleaning those anodes will require. I usually pull them from the tank and give them a good scrubbing with a wire brush, once each evening.

 

[jeffesonm]

Made some progress here...

To construct the temporary tub I used my old log sled as a frame and made walls out of old poly iso insulation and some plastic shelves. I lined the tub with a big piece of epdm rubber I was using to cover a wood pile. Determined to do this as cheaply as possible, I scrounged some rusty sheet metal from the woods behind my house to use as the anodes. I was going to suspend the mower deck from a ladder stretched across the tub, but figured it was easier to just rest it on some blocks and 2x4s on the bottom. Calculated 3' x 5' x 1.1' x 7.5 gallons/cu ft = 135 gallons = 8 cups of washing soda. Hooked it up with the 2 amp charger first to make sure it worked and then switched over to the 40 amp... now it's bubbling away at 25 amps.

 

[maple1]

Keep it coming.

 

[Ashful]

Nice! I find a twice-daily cleaning of the anodes is required in the first few days, then you can sometimes step down to once per day. They'll get fouled with grease, paint, and rust. I determine when to clean anodes by watching the ammeter.

edit: please verify that your anode connection and all light-gauge anode wiring is above the water line! Anode wiring below water line will vaporize. It's okay to have cathode wiring below the water line.

 

[jeffesonm]

Here's the deck after a few days in the bath. I gave it a once over with the wire wheel brush and put it back in for another day to finish it off.




All done. Parts went in a smaller bath and came out looking similar.




After the de-rusting everything got a coat of Rustoleum spray primer followed by two coats of Rustoleum JD Yellow spray paint.






Here it is back where it started, ready for reassembly.




I'm not going for a factory restoration here, just want to get it back in working order and hopefully stop the rust. I've got about 3/4 acre of fully shaded, tree covered, mostly moss and roots with the occasional blade of grass/weed sticking through, so the push mower works fine for the few times a summer I actually have to mow it. I really just want the deck so I can connect the Cyclone leaf rake I bought.

So far I've had to buy washing soda for the electrolysis bath($7), new bearings for the spindles ($20) and a new set of wheels ($14). I've made a parts list and plan to hit up the local hardware store to get all new stainless hardware in case I need to take it apart again. Leaves are turning so it won't be long before I have a yard full of leaves to cleanup...

 

[Ashful]

Nice! Another electrolysis convert. Now you need to go convert the guy who just fetched an old coal stove from his grandparents house. See the classic stove room!

 

[jdinspector]

Cool. I just cleaned some old cast iron pans and a pipe wrench about a month ago. Amazing. Last night I cleaned my dishwasher's metal filter that was clogged with soap, grease, food, etc. really cool way to clean metal.