Author Topic: Adventures in Anodising (Read 43734 times)

Avro · « **on:** February 22, 2017, 11:59 AM »

I have been messing around with anodising this last few weeks and thought I would share my early results. It was with some trepidation that I embarked on the adventure. You Tube videos make it look so easy and the results perfect; I knew it would not be like that! My apologies to anyone who actually knows what they are doing where anodising is concerned! That said I am happy to make mistakes and have a bit of fun with the process. Here is my set set-up in the kitchen, or rather what I now call 'The Lab' (you can probably guess that I am not married!!):
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...and here are the first victims, Suntour SCII pedal cages form a set of pedals I am restoring for my Laserlite:
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They have been stripped in a caustic soda solution. I have sanded then with 400 grit, then 800. It is a balancing act I think, how much metal to remove in order to get a reasonable finish whilst maintaining detail. The stamping on the ends is not very deep. After they were sanded I dipped them again to clean them and to remove the more stubborn areas of anodising, in particular where the screws have been. From now on it is rubber glove time. After this they are dipped in a nitric acid solution to to clean off any impurities from the surface of the metal.

Now we come to first major mistake. You have to suspend the item in the anodising tank by aluminium wire. I had read that where the wire touches the item to be anodised there may be left an area where the anodising has not taken. I wanted to avoid this so I just hooked the wire and hung the parts that way ERROR. All that happened was that the the electical connection was no where near good enough and the wire just spark eroded away and the cages fell to the bottom of the tank after a few minutes.

Take two and I wrapped the wire around to give a better connection. As it turns out you need a VERY tight connection in order for the process to work. I ended up crimping the wire tight in the end to avoid the spark eroding, I was thinking sparks and hydrogen are not a great mix. I future I will use nuts and bolts to make the connection, if any one has some M5 or M6 aluminium nuts and bolts I would be grateful for a few.

Anyway, here are the cages in the tank all wired up and bubbling away:
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After an hour I took them out and rinsed them off. They do not look a lot different at this stage, just the metal has a dull lustre to it. On the hob I had a pan with a solution of black dye at 50 degrees centigrade. Plop in go the cages for 20 minutes or so (I have recorded all the timings at every stage so that I can tweek things as I, hopefully, advance). The temperature is kept constant, too cold and more time is needed, too hot and you risk sealing the anodised layer too early:
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When the colour looks about right the cages are dumped into a pan of near boiling water for 1/2 hour or so to seal the dye in.
Here are the results of my very first experiment in anodising:
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Not too shabby although the picture flatters them somewhat. They are a bit patchy in colour but on the whole I was encouraged. I will redo them next week when I have some time off work.

Andyboy77 · « **Reply #1 on:** February 22, 2017, 12:05 PM »

Nice one Peter! Thanks for sharing this!

Ady · « **Reply #2 on:** February 22, 2017, 12:12 PM »

Thats amazing results mate..
Nice bit of kit looks expensive but rewarding to do.
You must be single or an understanding missus .
My other half would kill me..
Top work mate..
Cannot wait for the next episode..

Midschoolfool · « **Reply #3 on:** February 22, 2017, 12:19 PM »

Boiling up the awesome sauce

Nice job man.

Avro · « **Reply #4 on:** February 22, 2017, 12:29 PM »

I have done a little more work on this. I have had a set of Dia Compe MX900 calipers, with centralisers, for some time; originally for my Raleigh Aero Pro. The Aero Pro has now moved on but the calipers are perfect for my Laserlite. However they are raw and no evidence of any anodising what-so-ever. For the Laserlite they have to be black. So into The Lab!

The brake arms have been stripped and sanded with 800 grit, then 1200 then 2000. I then gave them a light polish. Same process as before. The first results were poor, patchy and uneven so I did not seal them and simply dumped them back in the caustic soda solution. I gave them another sanding, careful to try and achieve a consistent finish, back in the etch, back in the nitric acid, rinse, and start again.

It is difficult to calculate the amps required, I am using the fixed amps method, as you need to know the surface area of the parts. I decided to up the amps over what I used for the cages and see what happens.

Here are the brake arms prior to dipping:
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...and after:
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I have not polished these yet but I am thrilled! I think they are going to be good enough to use, I am really rather chuffed.
Hopefully there will be more adventures in anodising to come.

griff · « **Reply #5 on:** February 22, 2017, 01:18 PM »

Nice work Peter

Always good to see kitchen equipment being abused in the name of restoration

dancetothedrummersbeat · « **Reply #6 on:** February 22, 2017, 01:38 PM »

Great work! Well done

deeman · « **Reply #7 on:** February 22, 2017, 02:41 PM »

Great work mate...you will likely have a flood of pm's asking for this! It is about time the forum had someone reliable for anno

CustardLips · « **Reply #8 on:** February 22, 2017, 03:34 PM »

Good effort... looking pretty good them mate.

rooski · « **Reply #9 on:** February 22, 2017, 05:07 PM »

Dead good that, A bit of home Alchemy, love it!

Always a bit of trial and error involved in this type of thing, think I might have been tempted to use an old knackered part to begin with!

insectbones · « **Reply #10 on:** February 23, 2017, 08:38 PM »

Brilliant

Keep at it and keep posting as you go!

oldschoolace · « **Reply #11 on:** February 23, 2017, 09:10 PM »

That's ace

Would avoid taking on any work thought. A fickle process and fickle customers does noť a happy avro make

rodriguez · « **Reply #12 on:** February 24, 2017, 01:09 AM »

Another dimension

midschooljon · « **Reply #13 on:** February 24, 2017, 07:25 PM »

Nice work. This type of restoration work is really rewarding. Reading this makes me want to give it a try myself.

BMX1973 · « **Reply #14 on:** February 24, 2017, 08:36 PM »

They look great.

Avro · « **Reply #15 on:** March 24, 2017, 04:53 PM »

I have six days off work and had planned a spring clean and BMX restoration/build work. I needed the down-time after a hectic few weeks at work and was looking forward to it. My hopes were dashed this morning with a recorded delivery letter from my landlord to leave; two months notice given. I have often wondered if a casual view of my kitchen would instill visions of a meth lab but I have no knowledge of the landlord being in the flat of if he/she is a Rad member (giggles). Truth is I am a private tenant who dare not ask why.

Two months will fly by I know so I will have to look for a place asap, but also look to progress threads I have posted here. This may seem odd to some but the whole BMX thing has become a retreat, an indulgence and something I have enjoyed.

Therefore my hand was forced and, notice the leave letter in hand, I thought lets have a go at those pedal cages! I had already atempted to anodise the cages, my first ever attempt, and the results, were not too shabby. Some very rudementary lessons learned and a lot of experience gained along the way. Since my last post in this thread I had decided to put a lot more effort into preparation work, being that any paint job, or similar work, will always reflect the preparation time put in.

So here goes. This is actually my third attempt with the cages. To recap, the first attempt had the cages arcing with the suspending wire and eventually falling to the bottom of the tank due to erosion. The second attempt was very encouraging although patchy and revealing of underlying finish issues.

I stripped the cages again in caustic soda solution and desmutted for good measure. I then decided to prepare the metal more aggressively than before. I bought a palm (mouse) sander and a plethora of papers to begin the refinishing process, I also bought a plethora of wet and dry papers to work towards a finished patina. I used the papers from p80 to p120 to p240 with the palm sander until most of the scratches were gone or very faint. Deeper scratches, and one cage had several that would have to stay; they were either too deep or traversed stampings. Once a consitent patina was achieved with p240 I moved on to hand sanding with wet and dry, lubricated with water and a tiny amount of fairy liquid. The hand sanding went from p400, to p800, to p1200, to p2000 and finishing with p2500. Hours or work but goal orientated. I decided to leave the cages at p2500 and not polish; thinking this finish looked very consitent and acceptable (deep scratches excepted that to remove would have destoyed the cages).

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Avro · « **Reply #16 on:** March 24, 2017, 05:00 PM »

....so I then connected both cages to a length of aluminium wire and then dipped in to caustic soda solution until a uniform brown/black appearance was evident. Then they were dipped into a nitric acid solution (desmut) where the impurities are removed and the metal surface returned to a uniform aluminium lustre (more dull than what p2500 delivered). Throughly rinsed in de-ionised water and then into the anodising bath.

15 minutes in and the voltage has ramped up to 16.6v maintaining 1.17amps
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30 minutes in and voltage at 16.3 - 16.6v maintaining 1.17 amps
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1 hour in and 14.9v (close to optimum) at 1.17 amps; really good fizz from both cages.
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1 hour 15 mins in 16.9v holdign 1.17 amps; suspect one cage connection has eroded and therefore concluded the experiment although, given surface area estimates, still with in tolerance.
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oldschoolace · « **Reply #17 on:** March 24, 2017, 05:13 PM »

Love thread like this, keep it coming

Avro · « **Reply #18 on:** March 24, 2017, 05:22 PM »

...ok I am having terrible trouble putting pictures where I want them, the system of uploading pictures and then attaching seems out of whack. I will have to give up on the progression of the anodising process, complete with power outputs for the anooraks (like me). I have tried several time now and I just give up. The way you attach a photograph, and the order you upload it, makes no sense. Grrrrrrrrrrrrrrrrrr. May have to try the third persen route and use a hosting site but meh...cross.

Avro · « **Reply #19 on:** March 24, 2017, 05:43 PM »

....sorry for the lack of progress photographs, I like to see them so assume others do. The end result is 'puffs out chest, praised mathematics and chemistry, clears throat and declares 'SUCCESS'.

'puffs out chest a little more' the black colour is completely uniform. It is also very hard. I had previously anodised some brake calipers and they looked good but truth is I managed to scratch off the black surface with my nail on the edges of the casting. The coating on the cages is solid, like it should be given it is similar to sapphire.

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These are as they have dried out of the final rinse in de-ionised water. Once polished they will look like new. Sorry to sound so triumphant but I am thrilled. I guess I knew it was all about the preparation, and that is where all the time is. It makes no sense financially but the sense of 'omg' is high, at least when you first see the part out of the rinsing water.

griff · « **Reply #20 on:** March 24, 2017, 07:19 PM »

Great work

Possibly a daft question, but I thought with anodising that the polishing was done beforehand, won't polishing them now rub the finish off?

Avro · « **Reply #21 on:** March 24, 2017, 08:19 PM »

Rubbing down to p2500 is very like polishing by a different name. P2500, and of course even finer papers, is polishing.
You rather prempt my next experiment! I have a set of MX900 calipers that I need to be black (used in earlier experiments) that I have re-finished in the same way as the pedal cages. However, the brake arms are much more complex in shape.

The brake arms were my second victims for experiment, and initially my first success. They looked good but the black finish was superficial on the shape edges. I rubbed down the brake arms through the same process as the pedal cages, coarse with the palm sander and then by hand. However, the contours of the brake arms meant I had to be careful not to soften them. Having rubbed down to p2500 it was still clear that areas immediately after high spots, that is the low spots, where left differently texturally; like when you sand guide coat a car wing or door. I had noticed that when I first anodised the brake arms that the underlying finish had effected the lustre of the anodising. With is in mind I have gone beyond p2500 and polishehed the brake arms starting with Autosol and finshing with Finesse It: the later being what I have used before on car body work.

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This is a picture of the brake arms after p2500 paper and paste polishing. The finish is not only finer but more consistent as the paste polish is far easier to get to reach the complex contours of the brake arms. With the pedal cages, a consistent finish was achieved with p2500 alone and I felt that any brushed finish effect, if one should remain, would be wholly consistent and therefore acceptable even desirable. As it has turned out the finish to p2500 on the cages is excellent and, yes, a polish will only enhance the finish and give a shine. Hope that helps. I am still learning myself and loving it.

griff · « **Reply #22 on:** March 24, 2017, 08:24 PM »

I only asked because Jay (the lady who used to do a lot of radsters' ano stuff) told me that she had stuff polished before going in the tank. No idea if there was any post-ano polishing done, but just assumed that anything abrasive might fetch it off

Your stuff looks good though, keep it up

Avro · « **Reply #23 on:** March 24, 2017, 08:56 PM »

Polishing beforehand will give a better result no doubt, but polishing is only the abrasive action to a given surface it just depends on the degree of polish. I felt that the pedal cage finish was perfect, a final polish with a 'finishing polish' will only enhance this. The brake arms required a paste polish due to the contours demanding it. I am sure that if I had used a paste polish on the cages they would have been better out of the box as it were, but that was not the deal with those (there were deep scratches that I could not remove as too much metal would be consumed and detail lost).

I have polished the brake arms to a near mirror without loss of detail and expect the results to be good without loss of detail. I am still learning and experimenting.

I read the anodising thread in the stickies and very early on messaged the poster for a price for some anodising but received no reply. I have subsequently read on the forum a little as to the circumstances why this may have been the case. I hasten to add I am no professional, I do this in my kitchen! I am experimenting that is all. The brake arms have been 'polished' and I hope to anodise them in the next few days *crosses fingers*. I am sure it is all about the preparation as you say, same with any finishing work.

Super questions just bear with me, I am having fun and experimenting and improving with every experiment.

MartyC · « **Reply #24 on:** March 25, 2017, 08:07 AM »

Great work, those cages have come up great. I love stuff like this but have never tried it myself, good on ya for giving it a go

Author Topic: Adventures in Anodising (Read 43734 times)

griff

rodriguez

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