Author Topic: Rusty lump of metal  (Read 30092 times)

Stan

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Re: Rusty lump of metal
« Reply #15 on: March 08, 2008, 11:27:20 PM »
I agree Andrew, but I do think the electrolysis does a fine job of getting rid of the rust.  I've got to try that on some of the "other" collectables I have sitting around here.  There's some good descriptions on how to do that on smokstak.  It doesn't look hard, but evidently you should do it in the summer time due to the smell coming off the bucket.  One guy made a tub from plywood and plastic big enough to fit an entire tractor frame.  :)
Stan

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Re: Rusty lump of metal
« Reply #16 on: March 09, 2008, 01:18:42 AM »
I agree Andrew, but I do think the electrolysis does a fine job of getting rid of the rust.  I've got to try that on some of the "other" collectables I have sitting around here. 

Yes, the electrolytic cleaning does a great job on rust! My wife and I have a fondness for cast iron cookware, and I've cleaned many "rusty junk" pans with that method.
A plastic barrel, a good stout power supply, a piece of steel plate for a sacrificial anode (please don't use stainless), some water and a little sodium carbonate do wonderful things for cleaning rusty iron! Just make sure to get the polarity right, with the negative lead to the "part to be cleaned"  and the positive to the anode. Get it wrong and you'll be sorry....

I very highly recommend it for de-rusting old tools and machinery!

Steve
Steve

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Stan

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Re: Rusty lump of metal
« Reply #17 on: March 09, 2008, 01:24:39 AM »
Yah, I understand a 10 amp battery charger will do the job.
STan

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Re: Rusty lump of metal
« Reply #18 on: March 09, 2008, 02:54:22 AM »
How is this better than just sandblasting or perhaps glass bead blasting the rust away?  Does it act more aggressively on just the iron oxide and leaves the base metal un-etched?
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Stan

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Re: Rusty lump of metal
« Reply #19 on: March 09, 2008, 03:57:14 AM »
I've never done it but I have read lots from other guys that have and maybe Steve will chime in here but from all reports you are right, it leaves all the base metal and only takes away the iron oxide.  Many times you have softer base metal parts than rust and sandblasting will take that way first, the rust second.

I have sandblasted wood for signs, art etc and the effects which include leaving the harder parts of the wood while taking the softer parts away is the same.

Stan

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Re: Rusty lump of metal
« Reply #20 on: March 09, 2008, 04:42:34 AM »
I completely sandblasted all the rust and scale off the exterior of two VW diesel engines that have seen service in my power plant.  My efforts cleaning and painting the first, a 1.6 from an `84 Jetta were wasted as the motor was pooched.  I also sandblasted the Petter PJ-1 and attached genhead.  After paint this stuff looks like new again.
-DIY 1.5L NA VW diesel genset - 9 kW 3-phase. Co-gen, dualĀ  fuel
- 1966, Petter PJ-1, 5 kW air cooled diesel standby lighting plant
-DIY JD175A, minimum fuel research genset.
-Changfa 1115
-6 HP Launtop air cooled diesel
-Want Lister 6/1
-Large DIY VAWT nearing completion

MacGyver

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Re: Rusty lump of metal
« Reply #21 on: March 09, 2008, 03:30:35 PM »
Yah, I understand a 10 amp battery charger will do the job.
STan

A 10A battery charger might be OK... if you're not in a hurry.

My experience has been that battery chargers don't put out enough voltage to push the current I'd like most of the time.
I find that a lot of times it takes 20-30 volts to get the current I want. (usually 10-20 Amps)

The required current depends mostly on the surface area of the part to be cleaned (actually, the surface area that's "visible" to the anode) and the amount of time you're willing to wait.
More current cleans faster. Larger objects take more current than small ones.For a 10" diameter cast iron pan I run about 15 amps @ around 20-25 volts. It's not rocket science, the process works over a very wide range of current, higher currents just take less time.
15  Amps will usually get a crusty cast iron pan clean in 12-24 hours with almost no elbow grease on my part. Rust is removed fairly quickly. Heavy layers of cooked on carbon take longer.

One of the joys of electrolytic cleaning is that it does a great job of removing carbon and rust from steel or iron WITHOUT damaging the metal or changing it's surface texture.
It's pretty much impossible to "over do it". You can leave parts hooked up and cleaning for weeks without damage to the iron.

Disadvantages/things to watch out for:

1) The process makes a lot of hydrogen and oxygen. Do it in an area with good ventilation and no source of ignition.

2) Don't let the part touch the anode. Obviously if that happens, it shorts out your power supply. It can also make a spark which ignites your hydrogen bubbles.

3) It uses quite a bit of electricity. Most stuff I've done eats up 300-500 watts for 12- 24 hours. That's up to 12 KWH.

4) Iron or steel parts only!  Any brass, aluminum, or pot metal inserts or parts attached to the piece to be cleaned will probably be destroyed.

4) Get the polarity right. Negative to the "work piece", Positive to the sacrificial anode. Get it wrong and it will EAT UP YOUR PART!

5) Cleaning only takes place in "line of sight" to the anode, and cleaning is fastest where the anode is closest to the part. If you have a piece with deep crevices that need to be cleaned, you will need to make an anode that fits closely into the area to be cleaned but doesn't touch the work.

6) Watch out for trapped bubbles. Imagine cleaning inside a cast iron tea cup.(?)  If you put the cup right side up in the solution with the anode on top, then all the bubbles rise up out of the cup and float to the surface. That's good.
If you placed the cup upside down, with the anode on the bottom, then the bubbles would rise up and fill the cup and displace the liquid from the inside of the cup and cleaning action would cease. That's bad. Try and arrange your parts to avoid trapping bubbles.

7) Don't use stainless steel for the sacrificial anode. The electrolytic action will pull chromium out of the stainless and deposit it in the water. Chromium is very toxic, and your water will become "toxic waste" that needs to be properly disposed of. Plain old steel or iron plate works just fine. Pretty much any old scraps will do.

That's about all I can think of now. I've cleaned/derusted a few automotive parts, a couple old screw jacks I found under the house, and over a dozen cast iron pans, waffle makers, etc. The process really does do a great job of removing carbon and rust from an iron surface. Good stuff!

Steve
Steve

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MacGyver

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Re: Rusty lump of metal
« Reply #22 on: March 09, 2008, 04:47:07 PM »
Here's 2 photos of my electrocleaning hardware:
http://www.weirdstuffwemake.com/sweetwatergems/geek/electroclean.html

If you want to clean a lister block, you'll need a bigger barrel. :)


Steve
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lendusaquid

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Re: Rusty lump of metal
« Reply #23 on: March 09, 2008, 11:29:28 PM »
Just added another couple of pics of the cylinder wear for Mr Stan. For Electrolytic Rust Removal iam using a 4 amp battery charger and leave it on over night.Just started cleaning the rust from inside the fuel filter,dangling a nail connected to positive.I will see if its worked tomorrow.I did just buy this lump for spare parts,mainly the conrod and the flywheels.The flywheels on my engine had the keys badly drilled out and ive never been that happy with them.While i was collecting the engine i noticed another flywheel lying on the ground so i bought that as well for a few quid.It will make a nice garden ornament if i dont use it  ;D. That pulley looks well handy. I just hope i can get it and the flywheels off.I have broken the decompression lever and the cov handle so far through rushing things.Some of this stuff is going to need a long long soak.   

lendusaquid

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Re: Rusty lump of metal
« Reply #24 on: March 09, 2008, 11:32:32 PM »
I forgot to say, the current used in rust removal depends on the surface area of the part and also the strength of the solution.

Stan

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Re: Rusty lump of metal
« Reply #25 on: March 10, 2008, 12:23:32 AM »
Tnx for the pics of the cylinder wear.  One more confirmation of the type of wear near the top 1/2" of the cylinder.  I'm wondering why the listard process breaks down only on this area.  Mine isn't quite as bad as yours but is in the same place.  I'm going to run her for awhile and then see if I need a new cylinder.  Hopefully it won't be too bad as only the top ring "trespasses" on this area and the other rings will be enough to seal the piston for adequate running.  I only want another 100,000 hours out of her anyway on infequent power generation duty.  ;D

Stan

lendusaquid

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Re: Rusty lump of metal
« Reply #26 on: March 10, 2008, 12:31:45 AM »
Bit of filler and it will be allright, i wish  :-\

Stan

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Re: Rusty lump of metal
« Reply #27 on: March 10, 2008, 12:59:34 AM »
I've read lots of guys have used metalized filler like JB weld for cylinder repairs as long as it's not on a high wear area and not too big.
Stan

lendusaquid

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Re: Rusty lump of metal
« Reply #28 on: March 10, 2008, 07:33:14 PM »
Think i will pass on that one.It looks like good stuff to use on frost damage repair thou.

dpollo

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Re: Rusty lump of metal
« Reply #29 on: March 11, 2008, 05:16:25 AM »
Cylinder wear is usually greatest at the top, but in the uppermost portion of ring travel, the piston speed is not as great as in the middle so a good ring will cope reasonably well with the wear. It is not ideal, but it shouldn't cause trouble in a lightly loaded engine. Make sure the top ring lands are in good shape, Hastings makes a groove spacer (GL) which is easily installed if you have a lathe, or better, leave the job with a machine shop along with a new ring.  Should the top ring break, or if you have found the old top ring broken, it is a sign that a rebore is needed. Otherwise, remove the ridge, put new rings in, have a priest bless your work  and hope for the best.