How to join alumium and copper?
 

I'm planning my copper block/ aluminum heatspreader plan I posted about before. What I want to know is how bets to join the block and spreader. It needs to be strong enough to support the copper block and the tension exterted on the barbs by the tube.

I'm thinking plumbers solder like I use on copper pipes, but I'm not so sure how well it will work with two different metals. Any advice is welcome.

someone correct me if im wrong but you cant solder any other metal to aluminum at least not with any conventional method (here is where jaydee16 posts a picture of his old alu block with brass soldered barbs :D) , you can do alu to alu but thats it, and thats using mig, and tig

I would use a Permatex type silicone adhesive/sealant. Apply a thin layer,clamp it together. Only way I can ever get the 2 pieces apart is with heat....blow torch style. I tried blowing the block apart with water pressure,prying it,ect and couldn't loosen the 2 sides.
Permatex may also help with any galvanic corrosion as the 2 dissimiliar metals won't actually be touching.

LOL, I did it! Took several hours, burnt fingers, and a lot of patience! All I can say though is don't bother trying. The joint isn't to strong and it is a sever pain in the ass. Not worth the effort.

http://www.customcooledpc.com/aluminumWB4/006.JPG

You can also get A-LUM-RITE for welding AL to AL. http://divescoinc.com/ I got a bunch of it but never really played with it yet.

The block is all copper so thats not an issue. Any idea where I can get the stuff?

I would use some type of thermal epoxy if you want the heat spreader to actualy abosorb the heat from whatever it is attached to, or just use silver thermal compound and make some screw holes and screw it on. I tried looking up what your talking about but couldn't find anything.

if your any good with a welder there are a few welders that will bond different kinds of material. Mig and Tig would be a good start, if all else fails good old fashen arc. but your dealing with some soft metal so be precise and careful. STEADY HANDS

they make solders for dissimillar metals. ever see the guy at the flea market soldering copper fittings to an aluminum can?

"wonderod" is one brand if I remember right

Ummm... no.

What kinda flea markets do you have?


:D

huge ones that cover several acres and have no english speaking patrons :rolleyes:

as in a salesman type display?

In the HVAC world, where AL and CU are common everywhere, they use a transission (sp?) metal like steel. I have only seen it done with tubing though, going from copper transfer pipe to an AL coil.

Sounds like Shipshewana, IN (Amish = America's version of the Taliban). :rolleyes: :shrug:

Good food though!:D

Bob

Sounds like the most reasonable approach if I can't solder.

Silver thermal compound or Arctic Silver Epoxy is much better than any type of solder to transfer the heat anyway.

Yeah, if you don't mind another 8 deg C layer, in your block!:rolleyes:

The two metals should be fused together, if there's to be a heat transfer. Otherwise, I'd go with JB Weld, but the website isn't much help at confirming if it'll stick, plus we're not clear about the long term permeability of the stuff. The RTV silicone sounds best. Of course an o-ring would be ideal ;)

What? :confused: This isn't to seal a block from what I can understand. Sounds like he is adding a HS to the block. Is that not what thermal compound is for? Aiding in transfering heat from one substance to another?

Maybe I don't know WTF he is trying to do. :confused:

A link would be useful.

The first post here refers to a copper block, and an aluminium heat spreader, so I'm assuming that there's a requirement for a good heat transfer.

So how does JB Weld or silicone qualify for that over thermal compound/epoxy? You saying JB Weld or silicon is a better thermal compund than AS Compound/Epoxy? Maybe we should all start using silicone in place of Silver compound for our TIM joints on the CPU's? :confused: I have some silicon thermal compound at home from Radio Shack but it is worthless compared the Silver compound I now use.

I don't think there is any water contact with it. But hard to tell. I couldn't find what he was refering to by searching.

Read it again, I didn't say that JB weld or RTV was any better ;)

A link sure would be useful: i ran a quick search, and couldn't find the original design:shrug:

BTW, JB weld, with it's "iron" isn't even electrically conductive (!) (I checked it myself), so I'd expect dismal results, thermally.

Yeah I don't know whats going on. :D

superglue has decent thermal charateristics and adhesive qualities.

Sorry guys.

Imagine a flat alumium plate that cover the L shapped memory chips on modern AGP cards. Then get two and bolt them like a sandwich over back half of the card. Then simply attach two COPPER GPU blocks (no nasty battery effect, plus I have some 3/8 inch blocks left over).

I just want a way to connect the blocks. Right now I'm think I'll cut a slot for them and super glue them in by the sides. That or bolt them if I have enough clearance.

I'll see once I machine the thing. I'm just worried that even aluminum will be too heavy and theres no mounting holes on the 9600 Pro so it needs to be big enough to clamp together.

I think I get it. Your going to use the AL plates to attach the the memory to spread the heat and then Water cool the Al plates with Copper blocks.... So your trying to find something to attach the AL blocks to the memory chips themselfs? AS3 mixed with super glue I hear works. Try it on some scrap first and find out. Would be good to try and find a way to bolt them together though just for security sake. Wish I had a "modern card" to worry about such issues. The Old Radeon 7200 still does everything I need it to do including playing UT2003 and does it pretty well to boot. Would be nice to play it in 1024x768 though instead of 800x600. Well cards should be dropping in price soon....