How To: Rust removal

[Matthew P]

I'm a fan of electrolysis, but have been meaning to give molasses a go. Especially on something I'm not in a a hurry on. I'll have to check out Tubal Cane's rust videos. I was just watching some of his on making a foundry casting pattern today!

Matt

[Pete Ashby]

It's very much a case for 'horses for courses' and the size of your wallet.
I've tried all the the available methods over a restoration period spanning 45 years some are better than others for specific tasks others are quicker but perhaps more aggressive to the remaining surface material and some are quick but expensive.
I use virtually the whole range now on projects depending on the degree of corrosion, size of the work piece and base material these include the following:

Crushed glass high pressure blasting,

Good for frames and large chunks of body work, very quick and leaves a good finish but can be a problem if access to areas of the work is limited. Needs to be done by a commercial company if you don't own a large blast facility and all the kit therefore expensive but job done with no mess or hassle other than getting the work there and back, this is not a process you want to have done in you back garden I have a barn and no neighbors and a mobile man comes but there is a lot of dust and noise and fair bit of clean up afterwards.

Mechanical abrasion with various wire wheels on high speed grinders,

Good for small areas but creates a lot of dust and noise that can be a problem for the neighbors if you have any, not good for small delicate items and can be difficult to get into small spaces effectively.

Electrolysis,

Works well providing the anode and cathode are in line of site of each other, fairly quick doesn't make any noise or dust but does generate Hydrogen and oxygen off gas that's needs to be vented it's not a good idea to do this under the stairs in you house for example

Molasses

Excellent for all round performance and dead cheap, get's in everywhere and does it's stuff particularly good for cleaning up internal threads and small parts stinks a bit after a while though. But it is slow with capital S and works best if the temperature is above 15C I keep my bath in the poly tunnel I have toyed with the idea of heating the brew up to 100C as this should speed every thing up

Pete

[Mike K]

Was watching 'Wheeler Dealers' on 96 recently , Ed hired a soda blaster to blast a AMPHICAR body/hull they were restoring, he said its very slow but effective , they had the tub outside and the white soda was all over the place. Ed found a thick layer of bog on the rear quarter panel and many rust holes in other places. One episode they do a MB Jeep but its pretty corny , with the usual wrong facts quoted. The Jeep is supposed to be a 45 model but its fitted with a WILLYS script tub !

[charlie fitton]

"....dust but does generate Hydrogen and oxygen off gas that's needs to be vented it's not a good idea to do this under..."

Did this on the kitchen counter, on a very small scale.

Touched the foam with a match.....because.......and spent quite a while cleaning the evidence off the ceiling, cupboards, floor....

[Pete Ashby]

Originally Posted by charlie fitton

"....dust but does generate Hydrogen and oxygen off gas that's needs to be vented it's not a good idea to do this under..."

Did this on the kitchen counter, on a very small scale.

Touched the foam with a match.....because.......and spent quite a while cleaning the evidence off the ceiling, cupboards, floor....

There you are then H to O produced in a 2 :1 ration by volume, having once had a 200 amp tractor battery explode as soon as I turned the key after boost charging it a bit too long I'm very cautious of things that produce Hydrogen I never did find the top plate of the battery but the hole in the barn roof did suggest it's exit point.

Pete (older and wiser)

[Niels V]

just a small comment, Pete, heating the molasses to 100C would not be a good idea, that would decompose the different organic compounds in it.
I would not go above 60C.

and for electrolysis, do not use it for anything considered high strength steel.

[Pete Ashby]

Good points well made Niels

regarding the heating of molasses all that cross linking of sugars could end up with toffee .

Again your point on electrolysis of high tensile steels is very worth while bringing to peoples attention I should have mentioned that, the reason is it will lead to Hydrogen ion embritlilment so don't go using this on road springs or load bearing components.

Pete

[Jacques Reed]

Good Day,

I bought some Metal Rescue a while back and was wondering if others has the same results with it. It is the same type of rust remover as Evapo Rust and works via selective chelation as opposed to acidic methods.

I tried it and was disappointed with it. Despite removing all old paint and wire brushing a part it was very slow to remove a small amount of remaining rust and in fact after sitting overnight it still had rust on it. Had I used phosphoric acid the same part would have been completely rust free in that time and, in fact, I finished the job with acid.

I put it back on the shelf and just chalked it up to experience.

A few days ago I thought I would give it another chance. I had an old Ford flathead V8 fuel pump stand lying around so I thought I would see how it worked on the steel tube pressed into the white metal base. Metal Rescue claims it is harmless to non-ferrous metal so here would be a good test.
Again cleaned, and wire brushed before hand, leaving a minimum amount of rust. And again an overnight soaking. And again just a small amount of rust left in the small pits 18 hours later.

So one good thing- it didn't attack the white metal and in fact cleaned it up nicely. Probably removed the rust stain on it. For something like that with ferrous and non ferrous parts joined together it might be of some value. Things like the spark plug wire conduits with aluminium grommets or the distributor body with the white metal cap locator pin.

Perhaps I just got a bad batch but based on what I saw it do I won't be buying it again.

Look forward to hearing of others experience with this type of rust remover.

Cheers,