Welding a tank connector to aluminium

  1. hotponyshoes Member

    Messages:
    1,841
    Location:
    Somerset. Uk
    I have never tried the "brazing" type wonder fix rods but they might be ok?
    As above, watch some videos and see what you think.
    You could just buy enough parts to make one pipe and try it. You must have a mate you can borrow a blow torch off?
    Do you already have a drill and a tap/tap holder for making the holes in the ends?
    If you make it in alloy you will either need something like a cold cut saw to cut the plates or some way of cleaning all the cuts up after cutting as aluminium welding is very sensitive to dirt so any specs of paint from a hacksaw blade or dust from a grinder disc need to be completely removed before welding.

    If you had a working model you could the rest made up for you. If you cut and drilled/tapped all the end plates yourself there are a few guys on here who would give you a price to weld them onto the ends of the box for you. Might work out cheaper as just buying a gas bottle can get expensive.

    I would expect you will be looking at at least £1000 for a used ac welder with the other bits you need, probably more. So that is going to put a decent dent into the profit margin although if it's a one-off project you could sell on all the welding kit afterwards and make most of that cost back but you might have to spend a bit more in the first place on some branded kit if you want it to sell again easily.

    Personally, I would make the whole thing from round copper tube as it will be easy to connect pipes to the end using easy to find fittings. If you need flat mounting surfaces either get some copper sheet and cut a square the size you need then a load of smaller steps in rectangles to make a saddle you can clamp to the tubes with some thermal paste filling in the gaps or find some square copper bar, get a radius cut into one side and solder it in, or even cut into 2/3 sides and sandwich inbetween pipes.

    Another option would be to buy some big solid lumps of copper or aluminium and drill a load of holes through it, tap the holes each end for fittings.
    You will have to loop a few of the holes together with pipe unless you get creative with cross holes and blanking plugs but that way you can adjust the amount of cooing by drilling more holes if you need them.

    Copper sheet could be soldered up into boxes, you can buy all the stuff you need for that from screwfix/any hardware store. I can imagine it will be quite tricky to solder all the way around without melting the bits that have already been done and you might want some sort of jig to hold it all together.
    You could make it easier buy having the sheet folded into a u section to give you a start.
    Or you could buy a dc tig and weld the copper sheet that way.

    Another simple option would be to get a block of wood, drill through it with the same size but as the tube, cut it in half to give you a half-round former. Take the copper pipe, fill it with water, freeze it, then lay it in the half round and beat the middle of the exposed section down flat with a hammer. Then either clamp a bit of copper sheet on with some thermal paste or solder it on.

    Or copper tube, cut a section out of it and solder flat sheet in there.

    There are hundreds of ways of doing it without having to buy the kit. If you think the way you have planned will work then post up a rough drawing with the sizes on and somebody can give you a price to make it up or you will get some suggestions of ready made stuff that might be a suitable replacement .
     
  2. WorkshopChris

    WorkshopChris Forum Supporter

    Messages:
    4,717
    Location:
    South East Essex
    That's exactly what we used to do on the spot welding robots and mig welding jigs. Big lumps of copper cross-drilled all holes tapped so either blanks or tails to hose.
     
  3. James7519 New Member

    Messages:
    29
    Location:
    England
    The main reason for aluminium over copper was the massive price difference. It’s not many btus of heat it’s not like I have an amazon warehouse but I currently use 30,000 btu of AC to keep my room at ambient

    Even if I went the copper pipe with welded sheet ontop id need over 150m of copper pipe and the sheet to match.

    got a quote from China out of interest the aluminium bars 1630 usd including shipping. And they will even weld a 10mm end cap on for me. I just have to drill and tap the ends myself which I’m making sure I have the ability to do myself atm.

    the copper quote I got out of interest for 28mm copper 150m long to match the same usage of the aluminium quote with the sheet comes in at 2830 usd including shipping
     
  4. WorkshopChris

    WorkshopChris Forum Supporter

    Messages:
    4,717
    Location:
    South East Essex
    You are a braver man than me trusting them with something that will hold cooling water around a computer, QC is poor at the best as they dont care they have your money and you are 1000's of miles away. Also welding the caps before they are drilled is asking for problems technically as the air inside heats it wants to find a way out and can cause porosity or a crater as the last bit of weld finishes. (this factor will vary depending on the final dimensions of the finished part)
     
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  5. daleyd

    daleyd Member

    Messages:
    6,183
    Location:
    Wrexham, North Wales
    What kind of savings are you envisaging seeing from this system given the price of materials just for those components alone? Presumably you are going to need a fairly massive coil to sit in the pond as well as pumps, controls, isolation valves for individual servers, filters etc as well.

    Edit - didn’t mean that to come across as negative, the actual project sounds great I’m just curious as to the potential savings versus the cost
     
    Brad93 likes this.
  6. Brad93

    Brad93 M J B Engineering

    Messages:
    6,814
    Location:
    Essex
    I can’t work out if you’ve got money to throw away or if you’re hard up.

    You can get copper in thick tube and box or solid square stock.

    Personally I’d buy thick copper pipe, mill one side flat to mount your components on.

    You’ve failed to think about the fact that water tracks through pipes or vessels due to ‘thermoclines’ and weird things that happen due to turbulence dynamics.

    I mean if it was so easy to heat or cool water why do power stations have huge boilers with miles of boiler tubes, then huge evaporative cooling fans?

    Stop thinking about getting a leak proof joint joining aluminium to stainless or aluminium to brass. Whether that be by brazing or soldering. Or using lumi-weld magic Rods. They are zinc and will rot out in a matter of days.

    This isn’t a job to buy a welder to do yourself.

    Minimum of £1000 for an AC TIG welder.

    Sub it out.
     
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  7. Brad93

    Brad93 M J B Engineering

    Messages:
    6,814
    Location:
    Essex
    $0000s of dollars for crap from China. Good luck with that.
     
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  8. Pigeon_Droppings2 Member

    Messages:
    2,219
    Location:
    london
    Personally I'd use round copper tube and a standard size...because when something goes wrong (which it will) you'll be able to fix it easily.

    Using non standard materials is a recipe for disaster I reckon.

    What coolant are you using....and have you done a full risk assessment...ie what happens if you get a leak somewhere?

    Would it be possible to use an air heat exchanger to reduce the need for liquid cooling...I doubt it would completely remove the liquid cooling but might let you scale down the design to then use smaller diameter copper pipes which are cheaper because they are made in volume!
     
  9. Newlands Member

    Messages:
    166
    Location:
    Sussex, UK
    Oh look. A cpu cooler with round copper pipes soldered to a flat copper sheet. Blow me down. 8F75E783-9BAC-48A7-ACDB-8091063FB6A1.jpeg
     
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