Removing anodising from cranks

[FiveAlpha]

I am planning on removing the anodising from a pair of Shimano cranks, using caustic soda (sodium hydroxide). I am aware of the risks of leaving them in the solution for too long (it will eat the cranks as well as the anodising), but I wondered about pedal threads.

Is there something that needs to be done, to protect the pedal threads from having a tiny amount of aluminium removed, that might cause looseness? Or is this not an issue?

Thanks in advance.

 

[Nob]

Re:

 

[pete_mcc]

Re:

It’s really not an issue as long as you:
1) don’t use too hot water, this accelerates the reaction (don’t use cold though as it will take an age)
2) dip for a short time and repeat frequently rather than doing it once for a long time
3) have a bowl of clean cold water ready to dip the crank in to stop the reaction and brush it with a clean brush to get the soda solution out of the pedal holes and chainring holes

Little and often is the trick!

 

[FiveAlpha]

Re: Re:

It’s really not an issue as long as you:
1) don’t use too hot water, this accelerates the reaction (don’t use cold though as it will take an age)
2) dip for a short time and repeat frequently rather than doing it once for a long time
3) have a bowl of clean cold water ready to dip the crank in to stop the reaction and brush it with a clean brush to get the soda solution out of the pedal holes and chainring holes

Little and often is the trick!

Thanks for your help! I will be having a go tonight.

Not sure what the other reply was about - a picture of an American cleaning product that I can't buy, and won't help with the pedal threads!

 

[mattr]

If you've got any silicone sealant lying around, bung up and cover anything you don't want attacking by caustic. Pedal threads and the square taper spring to mind, and the tabs for the chainrings.......

 

[Nbike19]

You need oven pride,produced by home pride ltd,works a treat and won't eat away at your ally.

 

[mattr]

That's just a weak caustic solution. It will eat away at your aluminium, just do it slowly.

 

[FiveAlpha]

Done! I have caustic soda, so don't need branded cleaning products. Made a weakish solution, left it 10 minutes and now have some clean looking Shimano 6400 cranks! I used silicon in the pedal holes - good idea.

Now to polish, apply new decals and then lacquer.

 

[avalonian]

Have you a before and after photo ?

 

[FiveAlpha]

Didn't take any before pictures - will try and take some after ones tomorrow.