Ducati Sporting Club UK > General > Idle Chat > Best way of removing anodising?

[antonye]

Drain cleaner!

Technically it's Sodium Hydroxide (NaOH) but is sold as "Caustic Soda" drain cleaner - just check the contents to get a "cheap" one which is 100% NaOH rather than got lots of nice smelling soap and other additives in it.

Mix around 1 egg cup of caustic soda into each pint of warm water (REMEMBER: always chemicals into water, not the other way round!) in a plastic bucket and the you simply put some wire onto your part and drop it into the bucket. Leave for about 5 mins or until you're happy with the finish, then take out and rinse with plenty of cold water.

You may get some black residue left behind, but this is just the result of the chemical reaction. You should easily be able to rinse this away.

To dispose of the caustic soda you can just flush it down the drain - it's drain cleaner! Best to put a bucket or two of water down the drain after as well to clean it.

Beware that it is actually eating away the aluminium, so don't leave parts in there overnight. It also dulls the surface so you may need to repolish after. Also remember that because you've removed the anodising (the hard outer coating) it will be much softer now so will scratch easily.

Our local Asda sells it for about £2 for 500g (which is actually quite expensive) but it's easy to get and you don't use much. This is the one:

[Ghost]

Originally Posted by antonye

Beware that it is actually eating away the aluminium, so don't leave parts in there overnight.

I'm 59 now, but when I started work at 16 I had a Triumph Bonneville. Anyway one week the engine blew, I took the head into work and this guy said put it in that solution it will clean it properly. This was a Fri afternoon, Monday morning, all excited about my shiney head, I pulled out the steel exhaust/inlet stub everything had just dissolved.

[skidlids]

At the age of 16 we were using it for cleaning 2-Stroke Exhausts

[Jasper]

Originally Posted by antonye

Drain cleaner!

Technically it's Sodium Hydroxide (NaOH) but is sold as "Caustic Soda" drain cleaner - just check the contents to get a "cheap" one which is 100% NaOH rather than got lots of nice smelling soap and other additives in it.

Mix around 1 egg cup of caustic soda into each pint of warm water (REMEMBER: always chemicals into water, not the other way round!) in a plastic bucket and the you simply put some wire onto your part and drop it into the bucket. Leave for about 5 mins or until you're happy with the finish, then take out and rinse with plenty of cold water.

You may get some black residue left behind, but this is just the result of the chemical reaction. You should easily be able to rinse this away.

To dispose of the caustic soda you can just flush it down the drain - it's drain cleaner! Best to put a bucket or two of water down the drain after as well to clean it.

Beware that it is actually eating away the aluminium, so don't leave parts in there overnight. It also dulls the surface so you may need to repolish after. Also remember that because you've removed the anodising (the hard outer coating) it will be much softer now so will scratch easily.

Our local Asda sells it for about £2 for 500g (which is actually quite expensive) but it's easy to get and you don't use much. This is the one:

Thanks mate.Now,to find something big enough to take a swingarm!

[nelly]

I'd be very careful going down the caustic route on a DIY route. IMO, have a word with whoever is going to reanodise it for you and have them do it.
The anodising on the arm is more cosmetic than an engineering finish and won't be very thick. It'll probably polish off. It'll need polishing before refinishing so you'll be half way there.....
Alloy can dissolve at an alarming rate unless you're careful and know exactly what strength you need and/or are dealing with.

[Jasper]

Thanks Nelly.

[Col996s]

I have been looking at a method for doing small parts on my bike. In the end I attacked my side stand with some emery cloth and I was surprised how easy it was to get through to the alloy to be able to polish it.

[antonye]

Originally Posted by nelly

Alloy can dissolve at an alarming rate unless you're careful and know exactly what strength you need and/or are dealing with.

This is true, but an egg-cup per pint is a very weak solution so it will take minutes rather than seconds to do.

However, I agree that if you're not sure of what you're doing or if you're sending it off for anodising straight after, paying someone else to not f*ck it up is a good idea!

[skidlids]

I remember a rather pricey set of Mag yokes cracking when a set of nicely anodised forks were bolted into them, this was because the original anodised finish on them had been skimmed off by turning them down in a lathe and then re-Anodising them, the slightly smaller diameter that was left over stressed the mag yokes as they tried to clamp around them.

To me either skimming the surface or disolving it is still damaging the alloy So goes against what was called for in the original post