Dying aluminum

[atharp]

I was looking for alternatives to powder coat and paint to add color to my saber. I came across this tutorial
NEW LINK SHOULD WORK
http://www.observationsblog.com/scie...t-battery-acid

I was wondering if anyone knew morw about this. Lime can you control what part of a piece gets anodized? And if so what do you uae to keep the rest safe. Can you uae vinyl like when you salt etch?

Please any help would be nice

[San Tala]

That link isn't working for me

[atharp]

I edited the link should work now

[Sevinzol]

looks like a great opportunity to do some experiments. just remember Sodium Hydroxide (NaOH) is used to dissolve organic materials (i.e. melt skin and eyes) so be DAMN careful (gloves, goggles, etc.). The article uses RIT dye (liquid). I used it once to turn some old sheets into black robes for Halloween, I was very disappointed, as the sheets turned out a dove gray , no where near Black. anyone I've talked to about rit dye says its very muted colors.

what do you uae to keep the rest safe

second to the last line in the article says:

I have tried Sharpie and Krylon clear acrylic spray with some fair results

My suggestion:
Rio Grande is a jewelry wholesale supplier. I found this on their website.
http://www.riogrande.com/Product/Etching-Resist/118104
They only sell to businesses so you need a sales tax and use number to buy from them.
It says its Asphalt based. so maybe driveway sealer would work

[atharp]

Thanks for the info. I was also looking at the option of just painting the parts I want since they are mainly the recessed sections of the parts.

[Sevinzol]

Try this, looks like anodizing. should be able to find this stuff at an automotive store
MetalCast by Duplicolor

I used it on an external hard drive case. Worked nice but you have to do many light coats otherwise it will pool and orange peal.

[atharp]

Try this, looks like anodizing. should be able to find this stuff at an automotive store
MetalCast by Duplicolor

I used it on an external hard drive case. Worked nice but you have to do many light coats otherwise it will pool and orange peal.

that looks interesting.I never thought to look for automotive paints or supplies

[anne]

I was looking for alternatives to powder coat and paint to add color to my saber. I came across this tutorial
NEW LINK SHOULD WORK
http://www.observationsblog.com/scie...t-battery-acid

I was wondering if anyone knew morw about this. Lime can you control what part of a piece gets anodized? And if so what do you uae to keep the rest safe. Can you uae vinyl like when you salt etch?

Please any help would be nice

This is anodizing. RIT dye will color it, but for darker more vibrant colors you can get dye's specifically made for anodizing. For what you are describing, I mask portions of pieces selectively with red masking lacquer which can be bought through art stores, jewelry making suppliers and manufacturing/plating/anodizing suppliers (while your at it buy the lacquer stripper-- it'll make removing the lacquer easier after anodizing). Generally you want to anodize towards the lower voltage range for the piece if you want best color acceptance (which is why I use a variable regulated voltage, variable regulated current power supply called (inaccurately) a "rectifier" in the jewelry making field). You can DIY your own power source with a car battery, battery charger, a huge rheostat, and a bunch of 12v light bulbs for motorcycles. Since I do etching, electroplating and electroforming as well as anodizing aluminum and titanium I just bought stuff made to do it rather than trying the DIY route.
I have no experience substituting swimming pool PH lowering chemicals, so I don't know how that will effect the process, but when using a sulfuric acid solution 6V is about right if you want good color. Without going all techie, increasing the voltage decreases the size of the hexagonal aluminum oxide matrix (you can actually see it with a magnifier loop) which makes a piece with greater surface hardness, but smaller pores that don't take dye as well. There are a lot of places that sell the supplies. I buy mine from Rio Grande and Caswell (those have always given me good service)

Safety notes:
Doing this with a battery charger or car battery WITHOUT any form of voltage or current regulation is dangerous/stupid
Battery acid (sulfuric acid) can eat through human tissue and produces hazardous fumes, provide adequate ventilation and wear protective clothing

[anne]

I'm curious if you have tried the DIY approach to anodizing. The surface area of saber parts are small enough that you could use a car battery or other sealed lead acid battery for power. A link for reputable instructions for DIY voltage and current control can be found at http://support.caswellplating.com/in...ce-for-plating . With the process I use (30% sulfuric acid solution) a battery should handle it well (For example a 6 inch hilt section has approximately 27 - 1/3 square inches area on the exterior - I would anodize it at 6volts - 4 Amps(0.1 - 0.15 amp/square inch) if I'm going for maximum color saturation or 12V at 1.2 amps (.03 - .04 amp/square inch) if I'm going for maximum surface hardness for 20-25 minutes . As a general guideline I'll vary from 6v @ 6A/sq. ft to 15V@3A/sq. ft depending on the balance between Surface hardness (scratch and scrape resistance) and color intensity after the piece is dyed. Although when using sulfuric acid the best indicator as to time is when current flow stops falling on an ammeter. This is the point at which the acid is eating the oxides (an insulator) as fast as the anodizing process is creating them. I don't know if any of the voltage and current guidelines will hold true with pool chemicals.
On a safety note (of course use all safety equipment: gloves, glasses, respirator, apron, etc.) the gloves should be rubber but NOT latex (sulfuric acid and some of its derivatives breaks down latex rubber) rubber kitchen cleaning gloves work fine.
The most important (and time consuming) aspect is surface preparation. First, sand the area with finer and finer sandpaper to a mirror finish (then wire brush or rough sand a weathered surface back in if that is the look you want). Wearing gloves so no oils from your skin get back on the piece degrease (acetone, lacquer thinner or other degreaser). Now, clean with Softscrub, scotchbrite pad and distilled water. You should perform a "water break test" - distilled water should "sheet", not "bead" if your part is clean enough (There are youtube videos that show the difference). (Various chemical and electro-chemical processes can be substituted for these steps, but that would require buying equipment (like a plating rectifier) and chemicals (like lye) beyond typical DIY needs/budgets). PREPARATION IS IMPORTANT. This will effect the quality of your final results.
To selectively color you could mask and selectively anodize (what I usually do because I have the materials to make doing this easy) or you could anodize the entire part and then selectively apply dye with a brush (This might be easier in a DIY situation because you don't have to mask the part (just tape up the threads, end and holes).
If you have any questions about anodizing feel free to ask I've done quite a bit of prop, jewelry and small part anodizing. I have not done DIY power sources or substituted swimming pool PH lowering chemicals for sulfuric acid (I can't give any advice based on experience in areas that I have none).
--Anne