How To: Rust removal

[The Bedford Boys]

I've tried Molasses before and it does work well. However, being an impatient millennial, I bought a small tub of Oxalic acid from Bunnings and mixed a batch up in a bucket. I threw in a pile of rusty bits of a motorcycle I'm restoring and it stripped the rust overnight. Much quicker and cleaner than molasses.

[jack neville]

Electrolysis for me. No stink, no mess and overnight results.

[David Herbert]

Speed isn't everything !
BECAUSE molasses is slow it gets into places that faster methods miss. For example it will penetrate where parts have rusted together or small holes that have filled with rust. Faster chemical methods including electrolysis concentrate on the most exposed bits and are much less good at deep holes etc.
I have seen a 2pdr gun that had turned into a crusty lump of rust. The breach block was present and with a couple of months in molasses all the parts could be dismantled. It was very pitted but the moving parts moved. I was very impressed as I had seen it as scrap.

David

[charlie fitton]

.......and a further benefit to the Molasses method is less damage to the base metals....

and no damage to brass

[Mike K]

Have tried them all over many years , my favourite cleaner is Citric acid, I get it in 25kg bags , much cheaper that way. Downside is the solution must be kept at a warm to hot temperature for the process to be fast and effective. If the part is very dirty or oily a bath of caustic Soda first. Have dipped engine blocks in Citric , around here in dairying country the 200 litre plastic drums are numerous and cheap, cut them in half or lengthwise .

[Tony Smith]

Another option for smaller parts (it will work on much larger items, too, but the cost will be prohibitive) is a commercial product called Evapo-Rust.

Very effective, non-toxic, put your hands in it, pour it down the drain etc, but pricier than the other methods.

[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