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View Full Version : RFQ: Hard colour anodising



Mixster
01-03-2013, 11:34 PM
Hi all. I have an aluminium target archery scope. Its bare metal that i need to hard anodise in any bright colour (gold, purple, blue, rust/orange or red) so that its weather proof really or has the max corrosion/abrasion resistance possible. If any body on here offers small anodising jobs or can offer any advice or knows any person that does please let me know. Any help or advice appreciated.

Chas
02-03-2013, 08:39 PM
I do a little home anodising when the weather is suitable (ambient temps) but for proper 'hard' anodising you're going to need a specialist company. Google your local area & I can guarantee there'll be at least 5 or more . . . isn't Banbury in the F1 triangle?

You're going to have to phone 'em up & find one which doesn't have a minimum invoice charge (my regular charges 50min).

P.S. Spin 'em it's a prototype that you're considering for manufacture & 1 or 2 might even offer to do the job as a freebie :-)

John S
02-03-2013, 09:30 PM
P.S. Spin 'em it's a prototype that you're considering for manufacture & 1 or 2 might even offer to do the job as a freebie :-)

Doubt it, they have all heard that one before :loyal:

When someone tries that one on me I charged them double and tell them it will be credited when the other jobs come in. That sorts the genuine folk out.

Thought about asking Fiat for a new van and telling them I might be in the market for 10 more. Didn't work with them either, still had to shell out 14K.

Chas
02-03-2013, 10:31 PM
Doubt it, they have all heard that one before :loyal:

When someone tries that one on me I charged them double and tell them it will be credited when the other jobs come in. That sorts the genuine folk out.

Thought about asking Fiat for a new van and telling them I might be in the market for 10 more. Didn't work with them either, still had to shell out 14K.

It takes a smooth tongue from a handsome, suave, debonair, bon vivant type. But I find that sometimes the sheer cheek of it works.

I am the b#st#rd child of David Niven BTW :-)

m_c
03-03-2013, 03:06 AM
If you really want hard annodising, then it comes in Black or Dark Grey.

I was doing some reading up on it last week for some potential products, and due to the structure of the annodising, it doesn't take colours. Not that I was interested in the colour aspect, but I did find the explanation interesting.

blackburn mark
03-03-2013, 03:42 AM
i was tempted to inject liquid butane into a part to keep the temperature low enough for hard anodising, not a wise option at all considering a slight knock on the hanger wires would blow the roof off the shed.... but perfectly ok for mad science purposes :)

m_c
03-03-2013, 10:06 PM
Mark, have you got any guides to Hard Annodising?

I only had a quick search when I was looking last week, but it would be interesting to know what's actually required.

blackburn mark
03-03-2013, 11:05 PM
its been ages since I researched it, I pieced it together from various sights but most of it escapes me now.
me and another member (happy chris) had a go at the standard anodising, he was over the moon with it, I'm surprised he didn't try anodising the dog :)

I think (if may memory serves) for hard anodising you need to keep the temperature at 5*c or lower which is a tad difficult if your hammering it with a higher voltage (30v ish?)
I was after making ball sockets 50mm diameter, my thinking was to keep the bath very small, just big enough to fit the ball in and the liquid butane would cool the ball and the ball would in turn cool the acid
you could do with a none flammable to cool it but i'm not sure what?
or maybe have a closed (ish) system that exhausts the expanded gas outside?
or do some magic with an old fridge :)

Jonathan
03-03-2013, 11:35 PM
I'd try petiers for cooling the tank as they're pretty cheap on eBay. For testing you could just put the tank in a bigger tank full of ice, or just freeze some bottles of water etc, can't be that hard. Only guessing, but I expect a bigger tank is better as the current density will be more even.

m_c
04-03-2013, 01:02 AM
For cooling, I was thinking more of a coolant loop/heat exchanger running through a freezer with a thermostatic flow control.

However, the big issue seems to be finding out exact details. I've done a couple quick searches, and not really found anything definitive. I'm sure more searching will turn up more info, however it's not really a priority for me right now, and I was just wondering if anybody had any useful links/guides for future reference.

Jonny
11-03-2013, 10:58 PM
Think your nearest hard anodising place is in Nuneaton, used them a few times up to 14 yrs ago, not cheap either.
They will do most colours hard anodising but what they call gold/yellow is more like mustard colour same with other colours, they look naff.
Can even get ptfe impregnated hard anodising coloured and would only go for black or a darkish grey. All other colours seemingly look sickly.

For a scope sulphuric will be more than good enough as used on 3k scopes.
Many places will have minimum charge, Parkes in Walsall in 94 was 75+vat per colour. You might find one that will do cash but need to go in personally.
Just had some butt pad bits done in Brum today, dropped in at 8am, ready at 12.15.

Havent done any sulphuric anodising myself for at least 8 years, even done a few hard anodising jobs essentially the same with much lower temp.