Removing Anodising

TGR

Old School Grand Master
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Evening all,

I know this has been covered numerous times but i want to check what lye is and how i should mix it. Is it caustic soda? This is an extract of some instructions i was given -

Removing anodising is really easy. You need only about 10-15% lye solution. Here in Finland you can buy suitable lye solution from the grocery. This solution is normally used to clear slow running sinks. Then put the part which you want to strip to solution and it helps little bit if you brush item little bit. There forms some hydrogen gas so this is best to do in well ventilated area. Lye is also very caustic so good rubber gloves are needed. Stripping doesn't take long time, if you leave aluminium part in the lye for too long time it will will dissolve totally in it. So keep the part only for example in 20 secons or so at first and take it out and wash in fresh water. It is quite easy to see when anodisation is stripped off. When anodisation is stripped it is vey much easier to sand scratches off and polish item.

I wish i had a better memory, i know the alternative is oven cleaner - again do i use it all in a bag or just some?

Thanks all, hope you are enjoying the good weather (even i was out on the bike today!!),

Richard
 
Lye is pretty nasty stuff, I have used the oven cleaner bit, of course it is nasty too. Why do you need to remove the anodizing?
 
HI Steven,

I am removing deep scratches and polishing a stem.

Richard

p.s. it is sunny here - are you coming over?
 
Hi Richard

I've never tried it, but 'somewhere' on here 'someone' posted a really good photo guide to removing anodising with Oven Pride, oven cleaner. I've had a quick search but can't find the post at the moment.

It would be good to get all useful diy tips collected in one place :)

Hopefully someone will turn up with the link!
 
I also used a lye solution, but much stronger than the one you used. I put in a scratched DA 7700 crankset, but unfortunately the anodising didn't come of well at all. It came off in some areas and it didn't in others. I ended up leaving it in the solution for a longer period of time, hoping it would get better over time. Unfortunately the solution eat away chunks of the cranks.

Quite a few people seem to have better results with oven cleaner. You do need one with lye in it though, which most oven cleaners in The Netherlands don't have. Easy-Off oven cleaner apparently works miracles, but it isn't available here.
 
TGR":2svalznz said:
HI Steven,

I am removing deep scratches and polishing a stem.

Richard

p.s. it is sunny here - are you coming over?


Not this summer, although I came home from work and Grace had checked out Fodor's Guide to Ireland from the public library!
 
Steven,

A good sign, does the book mention sunshine at any point? It really is unusual. We are now into a spell of 14 days without rain - last time that happened was 7 years ago!! It is almost too warm to be in the garage - really it is that warm!!!

Richard
 
Why bother looking into what 'Lye' is when there are products been used and fared well on RB.

By the way Richard I've never heard of Lye! Stick to stuff you know works well like that polish you got me.

Ian.
 
Lye = Sodium (or Potassium) hydroxide, known here in Blighty as Caustic soda - if oven cleaner isn't strong enough, get some drain unblocking stuff :)
 
Couldn't have put it better myself Elysarian. I recently stripped a seatpost using a kids placky fishtank and caustic soda solution. You can buy bottles of caustic soda crystals from B&Q. For god sakes though, remember to add crystals to water, not vice versa. The reaction when they mix is extremely exothermic :shock: .
 
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