Ok so this topic is about :

How to clean those darned filthy caked on grimy alloy gearbox castings ... and then get them looking good afterwards ?

What is the best / easiest way apart from blasting of course !     

I've done the job many times now - petrol and scraping etc and wondering if there is an easier more modern way ?

Reason being a friend has asked me to rebuild his gearbox for him and he also wants it to look good as well as being mechanically spot on .... Doh ... friends !!

I'm good at rebuilding 'em        but hate cleaning them       :ranting  :ranting

I feel your pain Sir...
There are a few companies who offer chemical cleaning options, but its very expensive. The last one I did for somebody I had vapour cleaned, but they refused to have it near the cleaning tank until all traces of oil and gunge were removed.

Dishwasher seems to be the best bet. I'm on the look out for a restaurant / pub type one which can be repurposed as a casing cleaner at the moment.

Do not use the kitchen dishwasher if you wish to remain in any form of meaningful relationship with the management.

The other option is a hot pressure washer, but they are expensive to run and big cumbersome.

One method I have used when doing the odd gearbox for club members is to buy a 5 litre can of brake cleaner and attack the casings with a scrubbing brush and a toothbrush. That usually brings them up to an acceptable level. No vapour cleaned level, but good enough. I have a pressure pump spray for the brake cleaner. It usually uses 3-4 litres. All evaporates off nicely, which probably isn't great for my environmental credentials, but at least doesn't stink like petrol or diesel.

I've had great success cleaning motorbike cases with toilet cleaner, basically hydrochloric acid.  Wear gloves, it does sting after a while without protection.  Cheap and for me anyway it seems to work.  Degrease first with gunk/petrol/brake cleaner.

I thought most loo cleaners were alkaline based (bleaches and so on). Can you remember what brand or product you used?

Cheers Diffwhine I will give that a go      and I even have a respirator 

Chris, what brand bog cleaner ??

Quote from: geoff on Jul 17, 2024, 07:53 PMChris, what brand bog cleaner ??

The one with the highest % of acid.  I got mine (cough) from work, can't remember the brand

I thought bog cleaners were mildly acidic to counteract the alkaline lime scale.

Cheers Chris 

Quote from: Alan Drover on Jul 17, 2024, 07:57 PMI thought bog cleaners were mildly acidic to counteract the alkaline lime scale.

That would make sense. Perhaps I should read some of these bottles one day.

Chris - if its industrial cleaner, you are probably on to a winner.

Toilet Duck = Formic Acid

Harpic = Hydrochloric Acid

Cheers Chris 

Well I never. Every day should be a learning day, but I wasn't expecting to learn about bog cleaner from a Land Rover Club forum...

I believe stinging nettles sting with formic acid as do ants. How about shoving a load of nettles and ants' nests down the bog.

Mr Muscle aerosol oven cleaner and a tooth brush is my weapon of choice, then the hottest and longest wash program in the old dishwasher I've got plumbed in the cellar for car parts. A good pressure washing first gets the bulk off then attack as above.

Oven cleaner thanks