UKC

What is the easiest way to remove anodising from ally, caustic bath?

In reply to 3leggeddog:


Have you Googled it?

I typed in
"how do you remove anodising from aluminium"

And I got LOTS of hits.

Brilliant as this lot are, the worlds experts on anodising, are unlikely to be on a climbing forum , but I could Ve wrong.

In reply to 3leggeddog:

Sodium hydroxide will remove anodising along with a layer of the aluminium.

In reply to 3leggeddog:

Dishwasher did a pretty good job on the ally spoon I had. It left it all chalky in texture.

I bought a new one..

Craig.

In reply to 3leggeddog:

Take it climbing and place it repeatedly over the course of several years?

In reply to 3leggeddog:
Carry it around in your pack for a few years with all the other gear. The anodising will disappear.
Remeber if you use any caustic or acid treatment to remove anodising you will compromise the strength of the article. (Caustic works the same as sea salt, and will attack the grain boundaries. Leave it in long enough and you will have a crumbly mess. Acids attacks the grains themselves and usually the resulting products either dissolve into solution or become insoluble crystals.)
Very very fine emery paper would work, but just stay with the colour, or buy un-anodised gear.

In reply to 3leggeddog:

Out of interest, what are you trying to remove the anodising from and why?

In reply to johncook:

Exactly. ANY method to remove anodizing will weaken it (even sanding it off as will create micro scratches which act as stress concentrations).

One should not f*ck about much with ally climbing gear unless you really know what you're doing. I have modified and even made my own climbing gear; but almost exclusively steel items (such as beaks, nut keys and picks etc). Only ally item I have modded is an ice axe shaft.

In reply to 3leggeddog:

Any anodising company and many plating companies will strip it for you, that´s the easiest way.

In reply to crayefish:


Which is why nuts need to be discarded and replaced with new ones the instant they get scratched at all. Though if you post on here there's a chance you may find some reckless lunatic willing to take them off your hands.

In reply to deepsoup:


This is hilarious. You don't know what you are talking about deepsoup. You must throw away all your gear, because someone on the internet told you that "MICRO-SCRATCHES" will compromise the strength of your gear.

Crayefish, I will talke a 50/50 cut with deepsoup and provide postage for all your gear that has scratches on them. Today is a good day.

In reply to deepsoup:



That can't possibly be true. That would make each nut a use once product.

In reply to neilwiltshire:

This is one of the reasons why sport climbing has grown in popularity during the recession. Trad is rich mans game.

In reply to neilwiltshire:

Afraid so, I wrap mine in a little bit of cling film to stop them getting scratched.

In reply to neilwiltshire:

Gosh, you're right. I hadn't thought of that! :O)

In reply to johncook and crayefish:

You guys are funny. You made my day. I'm still laughing.

You do realize that to anodize aluminum it is dipped in a HOT alkaline bath, rinsed, etched in sodium hydroxide, rinsed in an acid bath and then anodized in a sulfuric acid solution?

And you're worried about scratches and sanding? The interwebs sure is entertaining. LOL

In reply to FreshSlate:
Clearly scratches on nuts are not a problem! But scored binners are... My scored binners are used for gear racking, not for dynamic loading.

You only need to tensile test a sample (much longer than it is wide... like a binner spine) to see how much micro cracks can weaken it. As an engineer I have done a lot of this and seen things fail at 70% of their previous strength!

Also one must consider warranties... if you remove anodizing from a binner lets say, then it fails and you hit the deck, it is only you at fault. All gear modification completely invalidates warranties and the manufacturer's liability.

In reply to FreshSlate:

Sarcasm alert!

In reply to crayefish:

Micro cracks! Wonderful! Not heard this one before! Lucky the aluminium on nuts is the special kind that doesn't form micro cracks. Too many lose there lives resting on sport climbs as a result of scored bolt-end carabiners. We must stop this injustice, and stop using carabiners made out of this brittle crack prone material.

In reply to deepsoup:

You need to flag your humour better.

In reply to 3leggeddog:

Christmas Troll. I collect 5 pounds... god damn it you lot... you need to stay on your toes.

In reply to wivanov:

Is it OK to scratch my nuts in the bath?

In reply to Turdus torquatus:

Yes, but it must be a hot acid bath and you've got to rinse them in acid again afterwards. Then they'll change colour and be safe to use. It will get rid of the crabs too though, so you need to think about that if you want to keep those.

In reply to crayefish:


My guess is that any life / injury insurance would also be invalidated.

Modifications do not just affect warranties, for example my daughter was puzzled when she had an additional charge on her insurance as her car was 'modified' from the original.

After much scratching of heads, we discovered that it was because she had a sticker advertising her company added to the door ( she was already covered for business use)

Any get out clauses will be exploited by insurers, so I would be reluctant to use any ' modified equipment', the ramifications could go further than you might expect.

In reply to nniff:

Thanks. That helps. Will they still retain their purple hue?

Lol... got to love assumptions based on zero engineering knowledge!

Admittedly aluminium is particularly good at resisting crack growth (it has a rather long critical crack length) but that doesn't mean stress concentrations don't affect strength.

Yeah... a scored binner is very unlikely to fail, but why encourage it just for the sake of changing the colour? Small risk but no gain.

In reply to crayefish:

Oh dear... The microcracks myth comes back from the 90's to haunt us all yet again... Someone please think of the children

In reply to JJL:
I was trying to be subtle.

In reply to crayefish:


Yes I do. That's why I love the micro crack scare stories. You're not the first and you won't be the last!


Starting to get somewhere here! Good. However stress concentrations cover so much though, the whole anatomy of the carabiner is designed around this. Of course the shape of the carabiner affects strength so it is kind of redundant saying this. You're talking about the existence of unseen micro cracks caused by sanding or removing the anodising.


Not really sure what he's trying to do and/or why. It could easily be an art project for old gear.

In reply to mike kann:

and to think they're still going. the mind boggles :P

In reply to 3leggeddog:

Oven cleaner works. Don't leave it on too long because it actually dissolves the aluminium. There's loads if you search google.