8 replies to this topic

[Gaz66]

Is caustic soda ok to clean engine parts and gearbox castings?

[DomCr250]

Don't use it on anything made out of aluminium.

 

Diesel is good, or if can get hold of it Kerosene which is basically paraffin - cheaper too.

 

Used jizer degreaser to good effect too.

 

Don't ever use petrol, my Dad burnt the skin off his face, hands and right leg washing a motorbike crankcase out in petrol - the fumes were lit by a fluorescent light fitting starting.  Blew up in his face with his hands in it, fell backwards and the bowl spilt on his leg.  Took him ages to recover and I can still remember it 50 years on.

Edited by DomCr250, 13 January 2022 - 09:56 AM.

[RooBoonix]

I use a citric acid bath for rust removal, removes rust relatively easily and it's not overly aggressive. You can buy it in powder form from ebay. I find it works well enough at 10% concentration.

 

For degreasing I use whatever I have to hand, I normally have some sort of degreasing chemical about but as DomCr250 mentioned above Kerosene is a good one.

[Gaz66]

I'm mainly wanting to clean gearbox castings and need something that will not only degrease but take old paint off too.
I want the castings "as new"
What do the pro's use to do this?

[GraemeC]

Usually either chemical stripping or blasting with the right media - aqua-blasting probably being the best.

[Gaz66]

Usually either chemical stripping or blasting with the right media - aqua-blasting probably being the best.

This is what I want to know ideally. The chemical used.

[floormanager]

A case I bought had been aqua-blasted.  It was completely clean.

[Spider]

I used to have a hot tank of caustic. Works a treat on cast iron, steel etc, but don't use it on alloy bits.

 

Heating it makes it work much faster, but even cold, it works well, just takes longer. It's good for removing some paint, but works well on oil, grease, carbon deposits etc. It won't do a thing on rust.

 

You will want to really flush the parts well after as the caustic is alkali.

 

I used to follow the (hot) caustic with a cold acid bath to remove rust.

[RooBoonix]

At my old workplace we used a strong alkali bath, Metsoak was the brand can't remember the exact product, but I know it's not readily available to the public. Nasty stuff.

 

Any items used to get dunked for as long as needed to remove paint, carbon etc... then sandblasted to remove corrosion. If a nicer finish was desired, or if it was aluminium and wasn't going to be painted, then the vapour blaster was used.