320 pounds of heat sinks....

I've read past posts but still stuck whether or not I should spend the time trying to determine what's what and then trying to separate the metals. I was originally just going to take them direct to my buyer as is but I'm thinking I could do better than the $0.50/lb he's offering. I guess I'm still confused on cast aluminum versus normAl aluminum. Could I make better money going to a regular scrap yard if I knew how to separate the metals? I wouldn't ask this question cause I know it's been brought up several times but I'm sitting on some good poundage and I'm still confused. Help a newby out. Thanks.

What sort of heatsinks? Post a pic.

Being that I have over 300 pounds they vary. All of them from computers or servers though. I'll get photos up soon.

They should be Alum extrusions. Some are flat that, i put in the sheet alum, the find or bladed ones are Ext.

I'm hoping someone will share info on the heavier based ones that I've read are copper. Extrusion...... Is that cast? Does cast pay the same?

Almost top to bottom with alum prices. Ext. pays better around .55 a lb here. and cast was at .38 last time and may be lower now. Ive never foumd a cast heat sink tho. If you think its cast alum, hit it with a hammer and it will break, not bend.

I had a bunch with the copper "plug". I pried the fins back and cut through the aluminum extrusion and steel fan bracket until I hit the copper. Then I pried the extrusion off the copper. The yard gave me "copper foundry" (their highest rating) for the plugs. That part was great, the not so great was they gave me aluminum sheet for the fins instead of extrusion.

Bill

Glad i asked. I had no clue what extrusion was, based off the prices Mechanic shared, it was the highest paying. I guess i just need to identify the copper and remove that. Is extrusion heavy? i have a bunch what came out of servers and they are definitely bottom heavy, i was hoping someone would tell me they are copper. I need to take a grinder to them i guess.

All heat sinks with fins is extruded alluminum. If they have copper on them then take the copper off. Sheet alluminum is always bent or pressed to form the shape, extruded is drawn through a die to form the piece. If you look at the end of the heat sink you can tell thieres no way that alluminum could have been bent to make the fins. Cast alluminum is always pored into a mold and most of the time you will be able to see mold marks and the inside corrners will be rounded. I hope this helps, I don't know any other way to put it without being there to show you.

Scrapcrazy. just scratch the bottom with a nail or scerw or cut the side with wire cutters or a file and see what color it is on the inside.

Mech688, Ive come across those too. they were in old sterio receivers. also Ive found a couple that were solid ext. and they were nice and heavy. have to guess around 2 lbs a piece

Thanks everyone! I have so many of them and its obvious that some are copper and I think it would be worth my time to take the questionable ones to the grinder. It sure would be nice to find some hidden copper in some of this heavy ones. This may be this weekends project. I'll keep you posted.

Alum by me is
Dirty/furnace
Transmissions
Cast
Paint
MLC
Extruded
Alum Cans
Al rims
Cu/Alum Raidators

I would also have to disagree with you happyscraper. I have seen literally hundreds of different heat sinks. Some I will buy as extrusion, some as old sheet and some as MLC.

BTW Mechanic, MLC stands for "mixed low copper clips". This basically means that it is aluminum that has a small % of copper in it. My yard uses it as a catch-all, kind of like old-sheet. The difference between old sheet and MLC is the thickness of the aluminum.

On another note...has anyone done a price analysis on whether it makes fiscal sense to seperate the copper from AL/CU heat sinks? I know some yards will pay you Cu/Al radiator prices for them. I personally don't think the copper recovery is there to justify that price, but if you come to my yard I will pay you close to $1 a lb. with the fan still on them!

Lots of alum info here by grade type... GENERAL ALUMINUM INFORMATION from Aircraft Spruce

my yards here refuse to recognize qny heat sinks as extruded, even after I show them the extrusion marks on the sides and show them it couldnt possably havr been molded, most yrds still have no clue when it comes to comp scrap.