Aleph-X Heatsink Requirements

Status
Not open for further replies.
Jump to Latest
#21
gl said:
Aluminum anodizes almost instantly when cut and exposed to air. The layer of oxide is extremely thin buts it's there and protects the metal from oxidizing further. Anodizing uses electric current to build the oxide layer up. The oxide is harder than the bare metal so it's a bit less prone to damage. Anodizing also presents the opportunity to color the metal. It doesn't make that much difference to the heat radiating properties of the sink.

There is no need to paint the bare aluminum to protect it. Bare aluminum will, however, pick up fingerprints quite easily and these are a pain to remove. Painting, however, is a good cosmetic thing to do when WAF is important.

As for black paint being a better radiator of heat than bare aluminum - well I'm not sure. I build big heatsinks and for class A operation I haven't noticed a major difference one way or another. So I take the lazy way out and apply paint only in the places where it keeps things looking nice.

Graeme
Click to expand...

Building on Graeme's comments... Paint and anodized surfaces have a slight insulating effect (more so with paint), whereas powder coating supposedly does not. Thought I'd bring this up since the thread discussed www.conradheatsinks.com MF350 product which is powder coated. Power coating will not oxidize like bare aluminum nor turn purple over time like anodizing.

Personally I'd avoid painting, since it can chip and act as a thermal blanket. . As Graeme mentioned earlier leave it off the radiating surfaces at least.

-David
 
#22
> Paint and anodized surfaces have a slight insulating effect (more so with paint), whereas powder coating supposedly does not.

That is new to me.

Thermal conducitivy values:

aluminium oxide (anodising) 26 W/m/K
powder coat (polyester) 0.24 W/m/K
paint 1.45 W/m/K

I expect normal anodising layer to be less than 20um thick, and maybe 0.2mm or more for paint and powder coat ??


Patrick
 
#23
gl said:
I buy .187 aluminum sheet stock from onlinemetals and cut it up on the table saw to make my own DIY sinks. This has always worked well for me. The biggest advantage is the lowered stress of knowing that I have unlimited supplies of sink material available off-the-shelf and at the lowest possible price.

Graeme
Click to expand...


I would not mind seeing a DIY heatink using this method.
Graeme, could you visually share some of your work?
 
#26
Graeme brought his monobloc's to BAF 08. It was great to see them in person. BTW, Graeme is a heck of a guy and very talented as well.

Below is are links of Nelson's prototype amps given away at BAF 08. Have a look at the heatsinks which are made from tubular square aluminum! Very easy for the DIYer to make low c/w rated heat sinks to cover a variety of builds.

http://home.comcast.net/~burningamp/BAF_2008/My_Albums/Pages/TheEyeLady_images_from_BAF2008.html#7

http://home.comcast.net/~burningamp/BAF_2008/My_Albums/Pages/BAF2008_-_Vladimir.html#55

-David

Edit: Graeme, Vladimar, and me after talking about these monobloc's at BAF.

http://home.comcast.net/~burningamp/BAF_2008/My_Albums/Pages/BAF2008_-_Vladimir.html#74
 
#27
dw8083 said:
Graeme brought his monobloc's to BAF 08. It was great to see them in person. BTW, Graeme is a heck of a guy and very talented as well.

Below is are links of Nelson's prototype amps given away at BAF 08. Have a look at the heatsinks which are made from tubular square aluminum! Very easy for the DIYer to make low c/w rated heat sinks to cover a variety of builds.

http://home.comcast.net/~burningamp/BAF_2008/My_Albums/Pages/TheEyeLady_images_from_BAF2008.html#7

http://home.comcast.net/~burningamp/BAF_2008/My_Albums/Pages/BAF2008_-_Vladimir.html#55

-David
Click to expand...



Thanks Graeme for the link,
My metal working skills are terrible, but that doesn't stop me from trying. I'm really trying only to impress myself anyways.

Yes, the bus like wiring underneath looks like an atomic 300B amp, cleaner than Sukuma like wiring. Someone mistook the breadboard for a real PCB, so that's elegant work.

Anyone's work who makes it beyond clip leads and smoke is doing great in my book!
 
Status
Not open for further replies.
Top Bottom