Electrolytic Cleaning

[droopsnoot]

Also it is MUCH better to completely immerse the part - the bit sticking out won't be derusted!

Doesn't that have an effect on the battery charger clamps, as they would need to be immersed? Or would they be OK because they're not rusty to start with? I thought about using some old thick copper wire between clamp and workpiece, if that would be better. For me it was no big deal to just put the piece in again the other way up.

But I'm just starting out with this, using the bucket I normally use to wash the car, so taking on board all these suggestions.

 

[rtcosic]

You are being MUCH too sophisticated!

I use offcuts of mains cable stripped of insulation and just twist the bare wire around the part. Or any old oddments of mains flex or bits rescued from dead car looms with long stripped 'tails'.

For my permanently set up baths I have, variously, 22, 15 and 10mm copper pipe laid across the bath with the wired up parts hanging off it and connect the power supply clips to the pipe. With 2.5mm^2 wire I just bend a hook into it and loop it over the copper pipe.

The electrolyte itself is such high resistance that the extra resistance in scrappy connections is irrelevant.

 

[rtcosic]

This is my larger bath. It lives outside the shed. The bath is stainless steel and is used as the anode.





This is a length of 22mm copper pipe with bits of old 2.5mm^2 cable hanging off it. If I'm feeling enthusiastic I will clean the copper pipe with steel wool at the begining of a session. If I'm feeling really enthusiastic I will clean the ends of the wire too.



An old semi-deceased battery used to fool the battery charger into working. Note the scrappy old bit of wire to the anode and the battery clips. They are rusty because when in use the battery lives outside and the battery charger inside, with the leads exiting under the shed door.



The sophisticated bath.

Note the sheet steel anodes all around the bath. I just drilled each, put a nut & bolt and washers through and looped some old wire all around the bolts and nipped up the nuts. Connect the positive power supply to one of the bolts.

Can you see the second perforated plastic container nesting inside the first with the anodes between them?

Two bits of scrap wood drilled 10mm and two lengths of left over 10mm central heating pipe cut to length and pushed through. Soldered length of wire between the two lengths of pipe.

Note the carefully applied insulation to avoid short circuits between the anodes and this assembly.

Clip the negative power supply clip anywhere on the copper pipe.

Then just hang the parts off one or other of the pipes. As there is the second inner container I often sit heavy parts on the bottom of the container rather than hang them off the pipe.

With this arrangement the wood and pipe assembly with all the parts pre-wired up can be lifted in and out of the bath in one go.

You can see the stainless steel chain mail salad shaker thingy lurking in the upper right hand corner.

 

[M@tt]

looks a good setup!!

yeah i realised today i needed bigger anodes, so the plan is to do like yours and get some sheets lining the sides of the tub with an inner tub to hold all the partsin without them shorting.

Good to know about the copper bits not mattering if they're immersed as i did have that thought tonight as well

 

[MrFluffy]

Has anyone mentioned surface hydrogen embrittlement of the parts cleaned?

Adapted from a post by petersons tools, maker and restorer of antique handsaws. on the excellent practical machinist site. He's talking about restoring antique saws to working condition, and under those conditions hydrogen embrittlement matters much more than normal, but its still worth noting :-

if you use electrolysis, address this after you are done by laying your part in a dry place to "sun itself" outside in the sun..time in the sun ideally should parallel the time the part was in electrolysis--this allows free hydrogen to "boil" free of the part.
If you don't do this step, the part will be more brittle and crack more readily under stress...

 

[richweld]

Have a look at page 3 of this posting to be getting on with. The brakes work fine!

http://www.rover800.info/forum/viewtopic.php?t=2549&postdays=0&postorder=asc&start=30

Calipers, disks, brackets, nuts, bolts, pulleys, covers and every steel part you see (and a lot more!) has been electrolytically cleaned over the last few weeks.

Sterling work!!!!

I see how they look after painting. Do you have any photos of caliper piston prior to painting? Do you get sludge on the the shiny part of the piston and how did you clean it up? Scotchbrite perhaps?

 

[peterd51]

Hi

I had my charger running through and old battery and it worked OK.

It's a good idea to include an in-line fuse between the battery and the workpiece, 5 amp fuse should do, or you could end up welding your workpiece to the anode!

Regards
Peter

 

[droopsnoot]

Sterling work!!!!

Boom, boom!

 

[M@tt]

out of interest do the anodes have to be steel? i've been striuggling to get some steel sheet of a suitable size but i was in wilkinsons the other day and they have large baking trays for £1 but i'm pretty sure they were made of tin

 

[rtbcomp]

out of interest do the anodes have to be steel? i've been striuggling to get some steel sheet of a suitable size but i was in wilkinsons the other day and they have large baking trays for £1 but i'm pretty sure they were made of tin

"Tin" baking trays are tin plated steel, some are unplated steel and some may even be aluminium. Take a magnet to test them.

I'm not sure how tin would affect the process.

If you're interested I've got some perforated stainless steel washing machine drums which may be useful for putting bits in. Free for collection.

 

[rtcosic]

How does electrolytic cleaning affect the shiny plated finish of a brake caliper piston. Would be interested in seeing a photo.

Do you have any photos of caliper piston prior to painting? Do you get sludge on the the shiny part of the piston and how did you clean it up? Scotchbrite perhaps?

Just to clarify the following photographs. These are of the spare calipers that I dug out of the spares pile in the shed specifically to take these photographs for you. I don't have any 'befores'.

I only cleaned them to a moderate standard for storage. If I were painting and refitting these I would clean them to a higher standard.

The calipers were stripped prior to cleaning - remove piston, seal and dust seal. The pistons were just dumped into the heap of nuts etc using the perforated yoghurt pot technique described in an earlier post. As chromium is more 'noble' than iron there is NO EFFECT on it and you do not get any 'sludge' on it. If you have some detergent in the bath you may get some (non-electrolytic) removal of dirt/grease/brake dust, but not much.

The chromium plated part was not rusty - if it were then the plating has broken down and that piston is not really fit for reuse. I just cleaned the grease/brake dust off the plated part with 0000 grade steel wool. I assume very fine Scotchbrite would work equally well, but I have never used it - DO NOT use emery cloth! The piston face has developed some surface rust in storage in an averagely damp shed.

These are rear calipers and the piston has an internal mechanism for the handbrake. I did not disassemble this mechanism prior to electrolytic cleaning. I only painted the exposed faces and in the case of the front pistons the inside of them.







The calipers show the 'line of sight' effect. The inside of the 'fork' area was not fully derusted. If I were to clean these to a painting standard I would dangle a supplementary anode into the forked area to improve 'coverage'.

Has anyone mentioned surface hydrogen embrittlement of the parts cleaned?

Oh dear - been reading .com sites from the other side of the pond! This issue - and that of hexavalent chromium ions in solution from the use of stainless steel anodes - keeps cropping up over there.

He's talking about restoring antique saws to working condition, and under those conditions hydrogen embrittlement matters much more than normal, but its still worth noting.

As you highlight - 'special case' both from the point of view of both material and application.

I would only suggest using the technique for cleaning the sort of parts one would grit or bead blast. The parts I would suggest cleaning have lost so much material from corrosion, are 'non-structural' and my battery charger power supply limits me to low current density anyway, I don't loose any sleep over that issue - but I am aware of the topic. Note they do only talk about the possibility of surface hydrogen embrittlement under certain conditions.

Sterling work!!!!

I can't find a GROAN smiley. Boom, boom just doesn't hack it in this case!

It's a good idea to include an in-line fuse between the battery and the workpiece, 5 amp fuse should do, or you could end up welding your workpiece to the anode!

Good point - that's why I like the nested containers with the anodes in the gap. A 5 amp fuse would be too small in my view. I have one Allfrauds clever electronically controlled charger and that will pump out 5 amps day in day out. I have had it delivering up to 10 amps - but after a while there was a visible heat haze rising from the cooling vents, so I thought I had better remove a few parts to reduce current draw! It comes fitted with 20 amp fuse and has short circuit protection.

I also have an ancient cheapy one that can deliver over 5 amps for quite a while before bouncing off its thermal overload cutout.

I would have thought 10/15/20 amps would be more appropriate.

If you're interested I've got some perforated stainless steel washing machine drums which may be useful for putting bits in.

Good plan!

I had planned on setting up just such a bath using one of these, but I was given the stainless steel bath so dropped the idea.

I keep trying to work out how to use the whole washing machine. Somehow add anodes inside the rotating drum and add a 'wiper' connection to make the drum the cathode. Then just open the door, chuck in a handful of small parts and press start. Would be easier if I could get hold of an old top-loader from a laundrette. Could use the heating element to keep the electrolyte at around 50 degrees and then the process would go like the clappers! Add plenty of detergent and it degreases at the same time.

Then how about incorporating the filter to continuously remove the sludge? Maybe even add some rotating magnets to catch the the magnetic bits?

Up to a light industrial continuous process by then! Fancy setting one up in addition to your grit blasting setup? Royalty-free to you sir!


Otherwise just cut up the external panelling of an old washing machine/fridge/freezer, roughly clean off the paint and use that. The anodes in the nested containers shown in an earlier post came from some scrap modular steel shelving I dug out of a skip. Otherwise rebar is cheap and usually readily available.

 

[rtbcomp]

........
I keep trying to work out how to use the whole washing machine. Somehow add anodes inside the rotating drum and add a 'wiper' connection to make the drum the cathode. Then just open the door, chuck in a handful of small parts and press start. Would be easier if I could get hold of an old top-loader from a laundrette. Could use the heating element to keep the electrolyte at around 50 degrees and then the process would go like the clappers! Add plenty of detergent and it degreases at the same time.

Then how about incorporating the filter to continuously remove the sludge? Maybe even add some rotating magnets to catch the the magnetic bits?

Up to a light industrial continuous process by then! Fancy setting one up in addition to your grit blasting setup? Royalty-free to you sir!

......

A wiping contact would be best placed on the rear of the outer drum, on the axis of the inner drum shaft. On some machines there is already an earth brush fitted.

Perhaps anodes could be fitted to the door? The doors are usually glass but I'm sure I've seen a plastic one. The doors off tumble driers tend to be plastic, maybe the dome could be transferred to a washing machine?

The drum is usually fastened to the shaft with an aluminium "spider", I don't think washing soda and ally are good company?

It would be easy enough to feed the output of the pump into the soap dispenser. The fluff filter from a tumble drier would sort out very small bits of sediment.

The fun bit would be deciphering the connections to the controller/timer to get a slow rotation of the drum, keep the pump running and maintain the correct temperature.

 

[rtcosic]

On some machines there is already an earth brush fitted.

Handy!

Perhaps anodes could be fitted to the door?

My thoughts exactly.

The drum is usually fastened to the shaft with an aluminium "spider", I don't think washing soda and ally are good company?

Pooh! Hadn't thought of that.

It would be easy enough to feed the output of the pump into the soap dispenser. The fluff filter from a tumble drier would sort out very small bits of sediment.

Again, my thoughts too. I pondered adding an old cartridge type car oil filter, but it would block up too quickly with fine stuff.

The fun bit would be deciphering the connections to the controller/timer to get a slow rotation of the drum, keep the pump running and maintain the correct temperature.

Nah, that's the easiest bit. I've got three offspring to sort out electrickery.

 

[richweld]

rtcosic
Thanks for taking the trouble to take and post the photos and info on the caliper pistons.

I have used fine grade Scotchbrite on pistons, and would not use any type of abrasive paper.

I'm nearly finished making my 'sophisticated' electrolysis bath based on one of your designs, with modifications.

Wasn't intending using detergent; washing soda is a good degreaser anyway.

 

[rtcosic]

Thanks for taking the trouble to take and post the photos and info on the caliper pistons.

Only recently been taught how to use digital camera and I'm finally allowed to use it unsupervised, and how to download/upload digital images - so having fun!

I'm nearly finished making my 'sophisticated' electrolysis bath based on one of your designs, with modifications.

Oooo! Potential shiny bits and new projects to admire! Photos please when done.

 

[richweld]

Bath completed, wired up, but have a problem with battery charger. Its a very old battery charger, and appears to be rated at 4 amp. That what is written on the charger. It has thermal overload protection. When I switch on, the current draw goes off scale i.e in excess of 6 amp. After a few minutes the charger cuts out. I assume the termal overload cut in.

So what do I do. Will the charger be OK? Will it just cut out and then back on, or have I to get the current down with some bulbs. What do you recommend.

Edit. Looking back at post 13, I could alter the electrolyte concentration. I had used a 10 % solution of washing soda. So I've got to empty the bath and start again using an ammeter and slowly add washing soda to a bath of water?

 

[richweld]

Sorted. Diluted the electrolyte and now running at 2.5amps.

Here is a photo of the completed bath.



Annodes are bolted to wood plinth. Anodes can be removed individually or altogether. The cathode rails are 15mm copper pipe. Pipe clips allow various configuration of copper rails.

 

[M@tt]

that looks spot on!!! nice job

 

[rtcosic]

Sorted. Diluted the electrolyte and now running at 2.5amps.

Well done. Fairly easy really isn't it!

View attachment 10696

Streuth - mutated into a 'My Bath is More Sophisticated Than Yours' thread now?

How about some perforated plastic covers for the anodes to eliminate the risk of shorting?

Or a drop-in perforated steel basket to hang off the cathode pipes for small parts?

Or an aquarium heater to hold the bath at elevated temperature to speed up the process?

Or an agitator to help remove deposits as they are formed?

Or........

Well done though!

 

[richweld]

Streuth - mutated into a 'My Bath is More Sophisticated Than Yours' thread now?

No. That was not my intention. I took your design and modified with a wood plinth sitting on the lip of the bath. The sheet steel anodes are then bolted to the wood plinth so they cannot move. I just thought that was a better way of doing it.

I was going to put one of those plastic foldup boxes in the bath to cover the annodes and prevent risk of shorting, but it was just a bit too big. May cut one up to fit.

I'm sure there are different ways of setting things up, and ways to improve on the design.

The 50 litre bath/plastic box cost £4 from Wilkinson, and the other bits I already had from other jobs.