Thread: How to slow-clean gearbox housings?

I was also going to suggest oven cleaner. Burson's have a caustic degreaser (about $15 for 5 litres) that dissolves grease really well and doesn't leave an oily residue like fuels or spraycan degreasers do.

Originally Posted by POD

Caustic soda sounds like a distinct possibility- would need a plastic drum rather than a steel one?

Steel is fine for caustic soda. In fact it's better than plastic. However the aluminium will not be good. Caustic soda will react with aluminium to form Hydrogen gas.
If you leave it too long or too strong you will get Alumina Al2O3

[ame="https://www.youtube.com/watch?v=cILG0LjGGMs"]https://www.youtube.com/watch?v=cILG0LjGGMs[/ame]

Most de-greasers have magic chemical buffers to limit the reaction of the caustic with the Aluminium, but it only slows the process.

Originally Posted by Dorian

Steel is fine for caustic soda. In fact it's better than plastic. However the aluminium will not be good. Caustic soda will react with aluminium to form Hydrogen gas.
If you leave it too long or too strong you will get Alumina Al2O3

https://www.youtube.com/watch?v=cILG0LjGGMs

Most de-greasers have magic chemical buffers to limit the reaction of the caustic with the Aluminium, but it only slows the process.

There are non caustic oven cleaners avail.

Originally Posted by POD

Diesel sounds like it would do the trick, although might be a bit of a fire hazard having half a 44 full sitting behind the shed long term? Someone on another forum has suggested a biodegradable cleaner called 'simple green', perhaps I should do a small-scale experiment with cost vs effectiveness of each.

Diesel isn't a flammable liquid, only a combustible liquid, so you actually have to try and set it alight, it won't combust just by a spark dropping into the drum - you can weld next to an open drum of the stuff and not set it on fire, but if you're worried, get a 44 that has a removable lid, so once the housings are in there, you can seal it up. I would imagine it would be heaps cheaper than any commercial degreasers or other chemicals.

I've had half a 44 of diesel in my garage for a coule of years - in a sealed drum, and I weld, oxy, etc right next to it. I use it to soak stuff from time to time in small open tubs and I've never set one on fire. I have far more flammable stuff lying around, like most would - thinners, etc are far more dangerous.

Originally Posted by isuzurover

Diesel is not flammable. combustible but not flammable.

. . . So you mean diesel is... 'inflammable'. ?

Well I've been planning to do a little experimenting with some dirty scrap in jars of various stuff for a week or so and see what hoses off cleanest and most cost effective, but I'm being told on some other casting forums that I should just chuck the stuff in the furnace dirty and skim the rubbish off the crucible. I'd prefer it reasonably clean even for the sake of handling when breaking it down for melting, hate getting covered in greasy crap.

Originally Posted by POD

Well I've been planning to do a little experimenting with some dirty scrap in jars of various stuff for a week or so and see what hoses off cleanest and most cost effective, but I'm being told on some other casting forums that I should just chuck the stuff in the furnace dirty and skim the rubbish off the crucible. I'd prefer it reasonably clean even for the sake of handling when breaking it down for melting, hate getting covered in greasy crap.

and yet you own a Land Rover...

I do recall someone posting up in some forum on this site in the last 4-6 weeks that SC concrete cleaner was great for replacing prepsol (spray painting degreaser) at a fraction of the cost.

If that's right it would cut grease like Shintaro.

DL