Lens discoloring my heat sinks

robincnn

robincnn

Well-Known Member
I have seen discoloration on COB side of pin heatsink that is exposed to air. Also saw discoloration under COB. You can even tell that cob I used on this one. Anodized layer has changed, takes a while with sandpaper to remove the anodized layer
IMG_20170131_142305.jpg
Have not seen any impact on Heatsinks/cob performance due to this discoloration.

I have seen similar discoloration on extruded heatsink for boards. Again on led board side on areas exposed to air. No discoloration on backside. It's odd because both sides of Heatsinks has same temps with the boards.
Happens over time even on heatsinks that run under 50C. Must be anodization black dye oxidizing.
 
sixstring2112

sixstring2112

Well-Known Member
robincnn said:
I have seen discoloration on COB side of pin heatsink that is exposed to air. Also saw discoloration under COB. You can even tell that cob I used on this one. Anodized layer has changed, takes a while with sandpaper to remove the anodized layer
View attachment 3889849
Have not seen any impact on Heatsinks/cob performance due to this discoloration.

I have seen similar discoloration on extruded heatsink for boards. Again on led board side on areas exposed to air. No discoloration on backside. It's odd because both sides of Heatsinks has same temps with the boards.
Happens over time even on heatsinks that run under 50C. Must be anodization black dye oxidizing.
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thats crazy man,you can almost count the dies in that pic,looks like a vero shit all over the back of that heatsink lol
 
zangtumtum

zangtumtum

Well-Known Member
knight mare said:
They are using cheap black anodising that is not light fast so the light and heat make it fade.
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Hard anodizing produce 30 micron layer if you respect the righ time of the process, if you are under, near 5/10 micron, probably too fast process, and a thin layer in teory can do that type o damage on prolonged exposure to heat and light.
 
The Dawg

The Dawg

Well-Known Member
zangtumtum said:
Hard anodizing produce 30 micron layer if you respect the righ time of the process, if you are under, near 5/10 micron, probably too fast process, and a thin layer in teory can do that type o damage on prolonged exposure to heat and light.
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I Concur below Is My Cxb 5000K Mother Light That Has Been Ran At 100 Watts 25 Watts Each For 24 Hours A Day For The 4 Months And No Discoloration. Its Does Show Sloppy Tim Work Though. Now We Can Keep An Keen Eye On These Heat Sinks Cause This Light Is Being Turn Over To My Beloved Vero29 Gen 7 B Version.:hump:

IMG_5470.JPG IMG_5471.JPG IMG_5472.JPG
 
Pulpit_

Pulpit_

Well-Known Member
zangtumtum said:
Hard anodizing produce 30 micron layer if you respect the righ time of the process, if you are under, near 5/10 micron, probably too fast process, and a thin layer in teory can do that type o damage on prolonged exposure to heat and light.
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Makes sense, I also suspect it's the light intensity as well as heat. Not all grades of aluminum anodize properly, I would guess these were made from 1100 or 3000 series aluminum which is not recommended for hard coating. it's basically pure aluminum (very soft) and unalloyed, but it is the best grade for electrical conductivity. I have seen some crazy results from customers anodizing product and the results can change from using different billets.
 
G

goofy81

Well-Known Member
goofy81 said:
Cheap anodize dye?
Probably heat + light intensity?
That being said, one of my heatsink is like that because it was next to a metal halide. The entire side of it changed to that color. It wasn't even close enough to cause it to heat up. So in my case it was likely the heat source.
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Sorry. Must have been stoned. But I actually meant slight ir?uv? At the end
 
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