DIY Hardcoat Anodising

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LavaRed
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DIY Hardcoat Anodising

Post by LavaRed »

So, is there any possible way to do this in a somewhat home-setting? If so, how?
The reason I ask is because I have, of late, wanted to hardcoat anodize a few tubes and my Beretta pistol frame (which lost all of its anodising). But I don't want to settle for just painting it or just a simple sulfuric acid anodising.
So, anyone with the knowhow and experience want to chip in?

Thanks,
Lava
"There are no stupid questions, only stupid people". -MAJ MALFUNCTION
daleper
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Re: DIY Hardcoat Anodising

Post by daleper »

I've never done it, but if I understand correctly, you can do your own type III anodizing. The hardest part is keeping your solution at the correct temp as to get the correct cell size you have to stay within a couple degrees of 40 deg f or so. Warmer temps will cause larger cell sizes that are succeptable to impact breakage.
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Dr.K
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Re: DIY Hardcoat Anodising

Post by Dr.K »

It seems I read that someone used an array of 9v batts for anodizing...but I know hardly anything about the process, just what I've come across doing other research.

I've been moly coating all my stuffs lately.
Kyle O.
magnet
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Re: DIY Hardcoat Anodising

Post by magnet »

Here's a company that sells kits for hard anodizing. They explain the process here:

http://diyanodizing.com/files/DIY_HARD_ ... LS_KIT.pdf
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nutshot
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Re: DIY Hardcoat Anodising

Post by nutshot »

Are you sure you want to hard anodise type 3 ? Thats normally only used for moving parts that the cosmetic appearance doesn`t matter about .

Hard anodising has to be done at low temperatures and is very hard to colour dye. All the bits you see anodised in colours is type2 anodising which is what most people want to do .

Type 2 is great for dying and gives a nice hard wearing and corrosion resistant finish.

I only do diy type 2 anodising as I like to dye things so I`ll do you a guide for that . I`m not an expert just a diy`er so there are more complex things you can add like chillers and pumps etc but if your not doing it on a commercial basis to an exact spec and specific micron thickness this will work fine (well it does for me :) )

You need :

Large water tight plastic container . I use a tomato plant tray .
Sulfuric acid
Distilled water
Lead sheet
2mm or thicker aluminium welding wire or rod (Ti will also do)
Caustic soda
dc power supply , ideally a constant currant bench top power supply with 5 amp minimum and 20-30 volts but a car battery charger will also work.
Dye if you plan on dying the part . there is an ebay seller in the US you can get it from fairly cheap just search for anodising or anodizing dye) or certain types of clothes dye or other pigment dyes will work if the molecules are small enough
A pan big enough to fit your part in for sealing.


Here is a pic of my anodising tank .

Image

You want your acid / distilled water solution to be in the 15% region , exact isn`t the end of the world just somewhere around 12-15% should work fine. Always add acid to water and be careful your solution will get hot as you mix it so add the acid in small quantities and let it cool then add more . The more pure the acid the hotter it will get . Car battery acid is about 38% or if you can find it you can buy 98% from chemical suppliers.

Make your tank as big as you can as this will help keep the heat down.

Line your tank with a piece of lead sheet bigger than the part you want to anodise . Leave a bit sticking up above the water line to attach your negative power lead.

Thats your tank sorted

If your part is already anodised you need to remove that .

Easiest way is place your parts in a caustic soda solution and strip it off . Don`t leave it in too long as the caustic is eating your part .

From this point I`ll do it as if it was a fresh off the lathe part .

The part needs to be thoroughly degreased . I wash the part well in washing up liquid then rinse under the tap .

Next you want to attach your piece of ally wire to the part , I always scuff my ally wire with some rough wet and dry paper to remove any oxidization to ensure a good contact .
Attach your wire to your part . round parts I wrap it round then twist tight with pliers , tubes I bend it into a concertina type spring and pull it through the center of the tube . Your contact must be good . Any part your wire touches will not anodise so do it on a place that will be hidden when assembled.

Degrease again with more washing up liquid and from this point on do not touch the part with your hands as it will show in the finish . Thoroughly rinse under a tap holding onto the wire .

Put the part into a caustic solution and let it bubble for a few minutes to get rid of any oxidization . Rinse again under a cold tap to remove all caustic. You don`t want your part hot before it enters your tank.

Put your part straight into the anodising bath and suspend it in the solution . don`t let the part touch anything in your tank or rest on the bottom.

Negative lead to the lead sheet positive lead to the ally wire .

If you know the exact size of your part you can use the 720 rule to work out times and currant but you must have a cc power supply http://www.ndhsubmersiblescience.com/ano/720rule.html . Don`t worry about the volts just set them to max and they do there own thing.
My parts quite often are hard to work out the surface area and I don`t do cad etc so I take a guess but Ive done it a lot so my guess usually works .

If your using a car batter charger for power you get what your given power wise so just turn it on and leave it cooking for at leased an hour but 90 mins seams to be the best bet for average size parts like end caps and silencer tubes . If your battery charger is modern link a car battery in line or it will keep shutting down.

For dying I find as long as the tank is in the 50-70 degree f region it works . Simple dyes anything works (black , green , red etc). dyes like gold which have metal partials work best around 70-75 degrees as the pores are bigger in the ally.
Through out the process I find its best to swirl the parts about a bit every now and then as hydrogen bubbles build up on the surface and reduce the currant draw (down side of not having a circulating pump or air bubble system in the tank).

You part has now been in the tank for your chosen time . remove the part and if your dying rinse it well in a pot of distilled water (do not touch the part with bare hands) If your not dying the part and are happy with silver with a gold tinge just simmer in distilled water for 10-20 mins.

Stick part into your dye (that you previously mixed ready with distilled water) and let it sit for a while . longer in the dye the darker it will get to a point.
Your part it now the colour you want it to be so remove from the dye and get ready to seal in a pan of simmering distilled water .

For really dark parts like black I boil my part in kettle full of black dye so I don`t bleed any colour out. Paler colours I hold over the steam of the sealing pan for a few minutes to close the pores some then simmer in the water for 10-20 mins .

Remove from water and your done :)

Best if you do a few practice runs on scrap parts before doing something that needs to be right as you might have a few hiccups along the way . I know I did :lol: Different types of ally anodise differently, some better than others . 60** types work well , Ive heard things like 7075 are a bit more awkward and need less time and don`t always take dyes very well .

Heres a few bits I have anodised using the above method

Image

Image

Image

If you want hard anodising the process is the same but you need a lot colder bath (near freezing) and you reduce the acid % of the bath . Never tried myself so you will have to do a bit more research and a few trial and error tests :)
Fulmen
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Re: DIY Hardcoat Anodising

Post by Fulmen »

I have some doubt about doing real type3 hard coat at room temperature with 12V AND being able to color it. My guess it's type2 or some modification of it.
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LavaRed
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Re: DIY Hardcoat Anodising

Post by LavaRed »

Sweet! Thanks nutshot, and you all. This is exactly what I needed!
Will post progress (and more questions) when I get to this project.
"There are no stupid questions, only stupid people". -MAJ MALFUNCTION
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