Jeeeez thats a lot of copper, fair play that should have some serious cooling power when done! Subscribed
To join the radiator to the aluminium shell I'm going to use four 1/4" thick aluminium plates: One for the front top, one for front bottom, one for back top and one for back bottom. Each will have thirty-seven 50mm X 2mm X 3mm deep slits cut - one for each of the fins. Now, to join them I can either put solder paste in each of the slits and solder it together, or alternatively fill each slit with one of the strontger araldite epoxies (2010 or 2011 iirc) or something like JB weld. Has anyone got any experience of the strength of any of these epoxies? They'll be quite a few joints so the weight (30kg-ish) will be quite well-distributed when lifting it, but I'd really appreciate it if anyone has any experience and can tell me if using a strong epoxy is a very bad idea?!
I'd go with soldering it. There's a problem of whether the fins flex if weight is applied to them. If you are using epoxy, I don't think it will stick well to a flexing surface.
I don't think there's any risk of the copper fins flexing - they're 0.9mm thick and the edges are only 20mm away from the nearest solder joints where the outermost pipes connect. Solder paste is probably the more sensible option, but it means I'll have to sandblast the aluminium as well. Might not be such a downside - the pieces of Al I bought have a few annoying scratches on them so would have to be sanded anyway, and soldering will add a bit of extra cooling from the aluminium.
Oh wait... aluminum plates. Scratch what i said. You need special solder and enough heat to probably ruin the copper joints. F that. I thought I read copper plates. Go for the epoxy.
Won't there be a reaction between the copper and aluminum? I would strongly suggest a non conductive material between the copper and aluminum. This project is awesome!!!
Great work so far. Have you considered cleaning up the copper and then coating it in clear laquer to protect it. It will stay shinny for ever and cost a lot less than power coating. Heat dispersal will be the same too. Using Aluminium and Copper together you will get galvanic issues the only way to get round this is not to use Aluminium at all. You'll still get it if you use any chrome plated joins etc but to a much less extent.
The trouble is, if the mobo tray sat on the back wall the psu and cables would need to sit in front of it. Nah, I think the galvanic corrosion issue is only really where there's a conductive electron acceptor/donator such as water between the two, causing the two metals to act as a battery. But it shouldn't be an issue in any caes as they'll bw araldite epoxy between the two. I had considered that, but I think it probably would affect performance, and I'm not even sure how it could be done really - it's probably too intricate to spray lacquer between the fins. But thanks for the suggestion! I went halfway towards powdercoating - just had the initial low-pressure bead-blasting done and left out the powdercoating. Thanks for your support guys, and for the MOTOM nomination, though I don't think the worklog gap and lack of updates will/have done me any favours. It's been annoying not being able to work on this project and get it completed, though there's been quite a bit of unlogged work done since last time. So probably best I get on and give some details.....
Sorry for the delay in updating - I've been busy being a hospital minion! Time fopr a proper picture update - now has end-boxes and leak-tested. The end boxes have inner thin-walled copper boxes with thicker 0.9mm thick copper outer wall pieces epoxied on. Leak-testing was quite problematic, but it's now sealed okay. I did some flowrate testing using a 5-gallon barrel - with 2m of 1/2" tubing and an XSPC Edge cpu block it manages 1.87gallons/minute, which I'm very happy with. In the final build it'll also have a full-cover graphics card block inthe loop, and a lot less in length of tubing. Taken to be bead-blasted a few days ago - not perfect, and not shiny due to being blasted with tiny beads, but instead now a matt pink. Still, gives it more surface area I guess. Still needs some tidying up. The aluminium plates for the ends of all the copper fin ends to slot into have been cut and the ends of the copper fins slotted into place. They'll be glued into place with araldite 2011 epoxy. The plates will have steps cut to sit flush with the upright aluminium angle. Here's lots of pics - they're a bit muddled up atm, soi'll probably clean up this post a bit later....
before bead-blasting; leak-and flow-testing: The bead-blasting warped the copper wall a bit, but it'll be held to the aluminium angle upright legs with lots of m4 bolts so shouldn't be a problem when assembled. Pic showing aluminium plate with slots cut and copper heatfins sat in slots:
Thanks for the update! I was getting some stick for the MOTM nomination as you hadn't updated in a while. I can sleep at night now.
I can just imagine when installing the system " oh sh** i just dropped a screw" (into the myriad of cooling pipes)