Solutions for 'blackenng' aluminum?

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bchampig   1 W

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Solutions for 'blackenng' aluminum?

Post by bchampig » Sep 28 2017 5:46pm

Hi,

I am intersted in some simple solutions for 'blackening' my aluminum parts...brackets, etc. I know there are various poducts that will blacken aluminum through a dipping process, but I'm wondering if anyone has any specific suggestions. I have considered the duracoat and ceracoat spray on products but would rather not deal with the fumes. Anodizing at home seems complicated as well.

Any easy recommendations?

thanks,
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Re: Solutions for 'blackenng' aluminum?

Post by Raged » Sep 28 2017 6:02pm

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Kepler   1 GW

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Re: Solutions for 'blackenng' aluminum?

Post by Kepler » Sep 28 2017 6:20pm

Professional anodizing is the best solution presuming you have an anodizer in your area. I live in Melbourne Australia and have had lots of parts anodized over the years. It actually quite cheap to have done and is only a few days turnaround. $50 gets you a lot of anodizing. The minimum charge I was getting was $30.

If you want a pro finish, certainly consider anodizing. If you decide to paint it black, make sure you give the part a good sand and perfectly clean before painting. Use a spray cleaner like Carburetor cleaner after sanding.
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Drunkskunk   100 GW

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Re: Solutions for 'blackenng' aluminum?

Post by Drunkskunk » Sep 28 2017 7:01pm

It depends on what you want the black coating to accomplish. Different solutions will work better or worse depending on your needs, and goals. Here's a few off the top of my head:


Anodizing forms a hardened protective barrier on the part. it's actually rust - Aluminum oxide that's force grown on the surface. Aluminum oxide is a clear crystal that is nearly as hard as a diamond, giving a nice durable finish to the surface. the Color is just a Dye that gets trapped between the crystals. it's below the surface and doesn't scratch off easy. But Anodized dyes often break down in UV light, so the color can fade over time in sunlight.

Powder coating adds a thin layer of polymer resin that is baked onto the surface. it's very durable and doesn't scratch or flake off like paint can. Being a plastic, it doesn't keep it's gloss for more than a couple years when exposed to direct sun, and will lose gloss over time regardless. non gloss coats tend to last much longer, but either can be durable protectants for decades.

Automotive grade paints are thick, 2 part paints that are designed to hold up to sun and weather for many years. Of the 3 listed, this will give you the deepest, glossiest black finish. With care, the finish will last decades. They are fairly chip resistant but not as scratch resistant as Anodizing and powder coating. They are also expensive.

Plasti-dip. This is a liquid plastic coating. you can dip parts in, or spray on from a rattle can. the finish is plasticy looking and a bit rubbery, but it's fairly durable. it's also not overly hard to peel off and do over if you want. it will hold up a couple years.

Spray paint. Good spray paint can hold up for many years and look almost as good as automotive paint. It will scratch fairly easy and tends to chip and flake off of un-primered surfaces.

POR-15. This is a brush on or dip in type of paint. (avoid the spray paint version) It's more of a polymer coating than a true paint, and will form a hard protective barrier. It's an industrial black color, so you aren't going to get the deep gloss and rich black color of automotive paint, but it's meant for coating machine parts to prevent rust in dirty, harsh environments.

Truck Bed Liner is a brush on or spray on polymer. it forms a thick, rough textured finish that will stand up to just about anything. The surface takes on a black textured rubber look over time. it's extremely durable and hides many imperfections.
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MadRhino   100 GW

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Re: Solutions for 'blackenng' aluminum?

Post by MadRhino » Sep 28 2017 9:57pm

I like anodized for a bike. It is not sensitive to solvents and chemicals, or the melting agents when you ride in the winter. Add clear protective tape to places that are likely to rub, and you have a long lasting finish that you can clean with anything. Not the nicest finish but sure the most convenient to maintain. Anodizing has improved a lot, now the colors are deeper and a wider variety. The problem is with frames and parts that were previously painted, for stripping and polishing is hell of a job.
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Chalo   100 GW

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Re: Solutions for 'blackenng' aluminum?

Post by Chalo » Sep 29 2017 12:12am

For quick finishing of one-off parts, you can use a brush-on patina like this, but it makes a fragile surface. For durability, you'll need to coat it with spray lacquer or the like.
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nutnspecial   1.21 GW

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Re: Solutions for 'blackenng' aluminum?

Post by nutnspecial » Sep 29 2017 12:13am

Good info, tho I thought there might be a solution that didn't involve paint ? Like maybe hook a car battery up to a black cat and the aluminum . . . or something? :mrgreen:

Adding to DS's list, (possibly), acid etch primer, and truck bedliner spray. I've been liking both for various reasons/projects, each are fairly unique and super easy/cheap.

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Re: Solutions for 'blackenng' aluminum?

Post by Dauntless » Sep 29 2017 1:06am

Powder coating works real well on aluminum, along with being tougher than paint it's probably your best idea for doing it yourself. The powder is sprayed and at first sticks because of static electricity. The object is then baked and the thermoplastic melts together. Your local Harbor Freight is a cheap source for both the sprayer and the plastic powder.

http://www.eastwood.com/infra-red-powde ... watts.html

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Re: Solutions for 'blackenng' aluminum?

Post by amberwolf » Sep 29 2017 2:20am


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Re: Solutions for 'blackenng' aluminum?

Post by skyungjae » Sep 29 2017 9:06am

I'd look into local powder coat shops. It's usually pretty affordable for small parts and sometimes free if you develop good rapport with the shop. It doesn't take much to throw in some small items with another larger order. :wink:
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Re: Solutions for 'blackenng' aluminum?

Post by Dauntless » Oct 12 2017 2:25am

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