Thread: Well, that went well, not!

Thanks Rob and Greg for the info.

I have to say that oil and grease doesn't seem to bother the process, not at higher amps anyway. After spending about 18 hours at 5.5A i pulled the guard out of the bathe this arvo. 99% of the outside paint is gone, but there was still plenty inside. So i carefully positioned an anode in the guard (used clothes pegs to stop it shorting) and let it go for about 2 hours.....All the paint and scum is gone from that area, i just need to move the anode to the other end to get at it.

Why root around with electrolysis BT? Well if Ken hadn't then i would still be daunted by the thought of stripping and cleaning Blondie! Good job Ken and thanks for sharing!

Stu, a mere 5A would do, but i guess if it survives 40 it will survive anything.....

Originally Posted by kwijibo99

Step 8: let it dry and if painting the part prime it right away, if not then give it a good rub with boiled linseed oil or steam cylinder oil if you can get any (Phil?)
Cheers,
Greg.

I

HI Greg,
am watching this one with great interest.
Steam cylinder oil, confident I can get some of that

Phil

Hi All,
Rob, Ewan, You're right, given enough time and current the oil will eventually come off but it just slows down the whole process and scadges up your electrolyte.
If you're going to use molasis though you need to get the grease and oil off first because you don't have the heat you get with electrolsys.

Rob, adding the boiling water to the caustic certainly does result in a very energetic reaction but I found that this disolves the caustic more quickly and evenly. I found you get almost as violent a reaction if you add the caustic to hot water but it happens near the top of the bucket rather than the bottom and you increase the chances of getting some on you. You're spot on though that using cold water is by far the safest but with small jobs the stripping works much faster with a hot solution.
Once an old mate and I had to degrease and strip the subframe of a 4hp Sundial engine. We put it in a 44 gallon drum 3/4 full of caustic then lit a fire underneath and let it boil for a while. I remember being as itchy as buggery for the rest of the day and the clothes I was wearing near falling apart the next time the cook washed them but by christ it cleaned the engine good. (I never laid claim to being the sharpest tool in the box )

I use bi-carb mainly because I always have some around, I keep a box in the beer fridge to keep it smelling fresh and the kids use it when playing mad scientist (vinegar and bi-carb they love it). I'm sure washing soda would work equally well for electrolsys and maybe even for the kids experiments but how will my fridge smell? I personally would never use caustic for electrolsys, it's just too nasty and I couldn't leave the tank full with the kids around. The used electrolyte with bi-carb, and I assume washing soda, is actually very good for your lawn, presumably because of the high iron content but I reckon you would have a dead lawn if you dumped a caustic electrolyte on it so it would have to go down the sewer which probably isn't great either.

I forgot about the brown film, I use a scotchbrite pad for smaller bits and a dunny brush for the larger items, my cook went balistic when I put the black stained brush back in the toilet, she just didn't see the funny side.

Finally, and I think Phil will agree, 600 weight cylinder oil is the hands down, far and away besterest thing for keeping uncoated steel or iron rust free. Boiled linseed oil is nearly as good but it will leave your part sticky for a while afterwards.
The main drawback with cylinder oil is it only comes in 20lt or 205lt drums and a little goes a long way.
Cheers,
Greg.

Originally Posted by neksmerj

I have a huge tum tree in my back yard, with a branch hanging over the outside area where I work. I just don't know if it will support the weight of the bed.

Suppose I could throw a rope up and over it, and hang off it to find out.

The things we do in the nature of engineering.

Ken

A mate of mine told me a story from when he was young and silly. It involved a sheep that was not exactly his, nor his mates. The said sheep was tied to a gum branch ready for the knife. It was to be hung from the same branch. The sheep went crazy, did a bolt and snapped the rope that was holding it. My mate and his mate took off after it. Within seconds the gum branch they were under crashed to the ground. It was a huge branch. They let the sheep go free.

I am not sure if tum trees have the same type of behaviour as gum trees.

The events in this story were a huge coincidence. I am not suggesting this would happen. I just thought you would like to hear the story. LOL

Dean

Originally Posted by Stustoys

Reading through the thread again I found caustic, baking, bi-carb and washing sodas.
Does anyone have a favorite for the test?
Dishwasher powder is caustic isnt it? Woud that do?

-work, +graphite right?

Any current density you'd like me to aim for?

Stuart

p.s. Maybe I should see if I can get this stuff to conduct first. yeah should it should but does it?

To answer your question Stu...i use washing soda simply because it is both better and cheaper than baking soda or drain cleaner. It doesn't take much-only a tablespoon or so in 20 litres of water. the stronger sodas I use for etching aluminium or dissolving the hair of my coven in the drains. Bless their little cotton socks.

From my experience with this process my lessons learnt are have a big enough battery charger to dump 6-8 amps constant power if you are in a hurry, and have lots of electrodes surrounding the rusty object connected by copper wire. The electrolysis process seems to work on line of sight...your electrodes need to see every aspect of your workpiece for effective and fast rust conversion.

The other lesson is: blast the object dry with compressed air/towels/heat guns etc then oil it or paint it to prevent the rather rapid orange blight from forming on your newly rejuvenated surfaces.

Oh...I upgraded my ebay charger's bridge rectifier to take arc welding type loads for rust removal quicker than glacial pace. I think I saw 16 amps, slow popping filmy bubbles, orange scum and the creature from the black lagoon all in the first five minutes. YAMMV

Greg

Originally Posted by Ropetangler

Hi Greg and others,
You raise some good points Greg, I agree that de-greasing and cleaning of parts before de-rusting is a good idea, it keeps the electrolyte cleaner for longer, and should make for a more even rust removal process, but having said that I have found that even oily parts seem to come up o.k. with the electrolytic process providing that they have undergone treatment for a day or so. Thick grease might eventually be broken down too, but I would remove it first for the reasons you have given.
In your step 2, I think your method for mixing up a Caustic Soda solution is somewhat dangerous however. It would be safer to add the flakes of Caustic Soda SLOWLY to some COLD water. This is an exothermic reaction, and so the solution will get hot as you add the flakes. By adding the flakes to the water, if it started to generate enough heat to cause some spitting of solution, any drops of solution will be much weaker in concentration, than if you add the water to all the flakes that are to be dissolved. If you use hot water you run the risk of generating steam as the addition of flakes to the water will push the temperature higher, and it may go above boiling point. If it does, most likely undissolved flakes are likely to spread around, and as they will be wet, nasty alkalai burns are likely.
I agree with most of the rest of your post and I like your idea of using each solution to neutralise each other, but I do think that you may need more than just a few amps if you are de-rusting large parts such as a lathe bed, and need it done in a day or so.

I have not tried Molasses but have used vinegar at full strength very successfully. Greg you use Bi carbonate of Soda, have you ever used Sodium Carbonate - (Washing Soda, aka Lectric Soda)? Any particular reason for using Bicarb Soda?

I sometimes either dip the part if it is small or spray it with metho to assist with the drying before it begins to rust again. I'm not sure, but I think that there must be some fine particles of reduced iron, or maybe the surface is micro etched by the rusting and de-rusting process, which causes the brown haze to appear within seconds of its removal from the process. A stiff brush like a toilet cleaning brush is useful to clean the item down during its final rinse. (Don't ask how I found out about this.)

Another tip could be that epoxy paints are quite tolerant of alkalais, and wouldn't normally misbehave if some leached out of cast iron onto the paintwork. They do go a bit chalky though if exposed to excess Ultra Violet radiation. You can use epoxy as a primer coat, and then go over it with some enamel or polyester for example, if U.V. is an issue.

Hi Stuart, What Ewan said, Cheers,
Rob.

I agree with the info on making up caustic soda. Just like diluting acid from concentrated acid. Pour conc acid into cold water slowly.

I have this clear memory of Caustic Soda from High School. The soda pieces were shaped like small capsules but flattened on two sides. I distinctly remember that these produced a chilling effect when mixed with water. Nothing I have done since with Caustic Soda had repeated this experience. Maybe it was something else. I mixed up some "pearl caustic" (don't ask me what it is. Just granules.) at work recently. This created some heat.

Caustic Soda can be a very dangerous and damaging chemical. It gets used a lot at work for cleaning. I soaked some laboratory centifuge buckets in caustic for quite a while, some years ago. They were aluminium. I did not know what caustic did to aluminium. It cost $1200.00 to replace them.

Dean

One minor benefit of washing soda is if it is just rust you are cleaning up you can safely dispose of the electrolyte down the drain, your could even put it on your garden or on lawn.
The later is not such a good idea with caustic solutions.

Whatever the electrolyte if it has been used to clean up old painted machinery the paint could contain quite a bit of lead so the electrolyte should probably not be put down the drain.

BTW if you want to stop the object re-rusting, take it out of the electrolyte and wash off the crap and electrolyte with a water jet/hose. If you use a sander or wire brush or you handle it put it back in the bath again to soak and clean any grit or oil off the object and rinse again with ordinary water. Yes, when you remove it, it will start to generate orange rust (Fe2O3) within seconds but that is OK, its even good but don't let it go for too long.
Before doing this you need to have a deionized water bath already at a vigorous boil so you can then dunk the whole thing into the bath and let it boil for an hour or so. Then place the object in a bath of hot (100ºC) mineral oil for half an hour. This will generate a grey submicron layer of greyblack FeO that instead of being flakey will be bonded to the metal. Black FeO is rust resistant and just one treatment like this may last for weeks to months without going orange

This process is actually is a form of metal blueing. Repeated light rusting/boiling (oil bath is only done at the end of the last treatment) generates very fine layers of rust (Fe203) and subsequent boiling in deionised water is one way of blueing the metal. Some loose FeO is formed on teh surface as well and this needs to be taken off with a fine soft wire brush between repeats.It will not affect threads or other precise surfaces as the layers are very thin.

If you repeat this 10 -12 times it will will go a dense blue black like this


One stipulation, the water and the bath itself (stainless is best) must be as CLEAN as possible.
Cheap distilled water will not give consistent results and neither will reverse osmosis water, it must be super distilled or deionised water.

The gun bluers recommend using gloves to handle the object as skin oils will kill the process.

Originally Posted by kwijibo99

Hi All,
Rob, Ewan, You're right, given enough time and current the oil will eventually come off but it just slows down the whole process and scadges up your electrolyte.
If you're going to use molasis though you need to get the grease and oil off first because you don't have the heat you get with electrolsys.

Rob, adding the boiling water to the caustic certainly does result in a very energetic reaction but I found that this disolves the caustic more quickly and evenly. I found you get almost as violent a reaction if you add the caustic to hot water but it happens near the top of the bucket rather than the bottom and you increase the chances of getting some on you. You're spot on though that using cold water is by far the safest but with small jobs the stripping works much faster with a hot solution.Greg.

I agree with all you've said there Greg, but you would be safer heating the solution afterwards like you did on the Sundial engine mentioned below. You had a face shield on, but if you generate lots of heat, your brew can almost explode out of the bucket and shower you and everything nearby with hot caustic solution. If you have a steel bucket, (not galvanised) or a stainless bucket/ jam boiler or similar, you could heat the solution up to boiling point, and it will work very efficiently stripping paint, grease and rust if connected up in an electrolytic cell.

Originally Posted by kwijibo99

Once an old mate and I had to degrease and strip the subframe of a 4hp Sundial engine. We put it in a 44 gallon drum 3/4 full of caustic then lit a fire underneath and let it boil for a while. I remember being as itchy as buggery for the rest of the day and the clothes I was wearing near falling apart the next time the cook washed them but by christ it cleaned the engine good.Greg.

I can well imagine that it would have

Originally Posted by kwijibo99

I use bi-carb mainly because I always have some around, I keep a box in the beer fridge to keep it smelling fresh and the kids use it when playing mad scientist (vinegar and bi-carb they love it). I'm sure washing soda would work equally well for electrolsys and maybe even for the kids experiments but how will my fridge smell? Greg.

Bicarb Soda does all that and more, it is very useful household cleaner and air freshener, stain remover etc. Washing soda might not help the smell of the fridge, you need to chuck that old cheese out to fix that, but washing soda is the active ingredient of bath salts, but I'm not suggesting that you throw your other half into the de-rusting tank, no matter how warm you make it.

Originally Posted by kwijibo99

I personally would never use caustic for electrolsys, it's just too nasty and I couldn't leave the tank full with the kids around. Greg.

I see where you are coming from, but if you only mix a weak solution, just strong enough to get the required current flow, it wouldn't be too dangerous, but bicarb or washing soda would be safer, especially if the youngsters ever got their hands on the raw chemicals, so I would do the same if I had kids around.

Originally Posted by kwijibo99

The used electrolyte with bi-carb, and I assume washing soda, is actually very good for your lawn, presumably because of the high iron content but I reckon you would have a dead lawn if you dumped a caustic electrolyte on it so it would have to go down the sewer which probably isn't great either. Greg.

I think it neutralises an acid soil, suppresses the growth of moss and makes more nutrients available to the grass if you have an acid soil. A weak solution of caustic may well work in a similar way, but a strong solution will certainly give you a break from the mowing.

Originally Posted by kwijibo99

I forgot about the brown film, I use a scotchbrite pad for smaller bits and a dunny brush for the larger items, my cook went balistic when I put the black stained brush back in the toilet, she just didn't see the funny side.Greg.

Mine didn't either.

Originally Posted by kwijibo99

Finally, and I think Phil will agree, 600 weight cylinder oil is the hands down, far and away besterest thing for keeping uncoated steel or iron rust free. Boiled linseed oil is nearly as good but it will leave your part sticky for a while afterwards.
The main drawback with cylinder oil is it only comes in 20lt or 205lt drums and a little goes a long way.
Cheers,
Greg.

Have you tried lanolin or any of the lanolin containing compounds like "Lanotec" spelling??? Is the cylinder oil much superior?
Cheers,
Rob

HI Gre,
I concur with the steam oil, in fact the brand we use now (Morris Lubricants) actually cleans the surfaces it comes in contact with. It's not flash on painted surfaces, leaves a nasty stain.
The only other downside is the cost
We are now using Lanotec heavy duty but are still waiting for their new product which is supposed to be better.

Phil

Great post BobL, very informative. I had no idea you could do bluing that way. I must give it a try some time. Would the de-ionised water from Woolworths or K-Mart be up to the job, or do we need specialist suppliers?
I noticed on your photo of what I presume is a ball turning attachment, that you had a welded nut which certainly had not been polished up before the bluing process, but the result was as good as the machined surfaces. The end result looked as good as the SHCScrews, thanks again for the post.
Rob

Originally Posted by Ropetangler

Great post BobL, very informative. I had no idea you could do bluing that way. I must give it a try some time. Would the de-ionised water from Woolworths or K-Mart be up to the job, or do we need specialist suppliers?

Cheers RT.
Full details of the process I use are in this thread. - the description is in post number 16.

A bit of testing has shown me that the deionized water at woolies etc is not always deionized, some of it is distilled. If it really is deionized it is usually OK but you need a lot of it for big pieces. For example to blue that tool post and rotary table holder I used about 2L per boiling, and I "rusted and boiled" the parts 12 times so I used 24 L of water plus a few more for cleaning etc. If you are going to do a lot of blueing it will be worth finding a 20L plastic container and cleaning it up and buying deionized water in bulk. Just look for water purification businesses that sell it in bulk. I recently upgraded my water filter for my coffee machine from sediment filters to reverse osmosis. Adding a deionizing cartridge to that system didn't add much to the cost so I now have high quality DI water on tap - well, not quite - it generates about 12L/hr.

I noticed on your photo of what I presume is a ball turning attachment, that you had a welded nut which certainly had not been polished up before the bluing process, but the result was as good as the machined surfaces. The end result looked as good as the SHCScrews, thanks again for the post.
Rob

The weld does look a bit crappy - I should have brazed it instead but I don't have an oxy. I did polish the weld with the same scotchbrite wheel as I polished the rest of the tool post.
Blueing won't hide any sins, if welding spatter is left on steel blueing will coat nicely so that it turns into black spatter.
BTW I Blued those screws as well.

Originally Posted by neksmerj

Hi BT, thanks for all your input, I appreciate it.

My lathe was an ex Tech school machine, and the little darlings had over painted it sky blue with what looks like a mop, there was paint everywhere.

I started off with a power wire brush, but this was too tedious so decided to try electrolysis. A new learning exercise as well.

I've got the green paint sorted, it's the red colour inside the bed casting I'm after. I could probably just pick any red, but if I can get a close colour match, I'll feel happier.

Ken

KJ,

I had a look at the lathe this morning armed with a PPG icoat* colour card. Crimson R15 is a good match. RAL 3002 Carmine Red is nearly identical.

What did you end up with for green?

BT

* their industrial coatings range.

Hi BT,

Forgive my ignorance, what does PPG refer to? If I took your info to a Dulux Trade Centre, could they fix me up?

Another question if I may. I would like to know what treatment is given to the HERCUS name cast into the side of the bed.

ie, what colour is the raised lettering, and what colour is the recessed background. I haven't got one photo of my bed prior to undercoating.

I have also sent you an email.

Ken

Originally Posted by neksmerj

Hi BT,

Forgive my ignorance, what does PPG refer to? If I took your info to a Dulux Trade Centre, could they fix me up?

Another question if I may. I would like to know what treatment is given to the HERCUS name cast into the side of the bed.

ie, what colour is the raised lettering, and what colour is the recessed background. I haven't got one photo of my bed prior to undercoating.

I have also sent you an email.

Ken

One of the oldest paint brands in the market, Taubmans has been painting Australian homes for over 110 years. In 2007 PPG Industries acquired the Taubmans brand. Back in the early 1900s, George Taubman built the company on a foundation of technical superiority. Taubmans' new owners, PPG, also have a long history of applying global technologies to gain a competitive edge.

Dulux will match other brand colours.

Red lettering yellow background.

BT