Attaching copper pipe to aluminium plate

Bajr · Post by **Bajr** » Mon Aug 31, 2020 9:40 am

I’m new here so apologies if this has been dealt with before.
I’d like to make a water-tight seal between 22mm Cu pipe and Al plate. It’s an out-flow from a ally tank pond to a copper cascade and rill.
I don’t think welding would work, but what about brazing/soldering/epoxy or just rubber gaskets and bolts. What’s my best bet?
Many thanks from a newbie.

Bob225 · Post by **Bob225** » Mon Aug 31, 2020 10:58 am

for ease would use a 22mm bulkhead fitting aka tank fitting, i take its a water feature and doesn't have any fish

seal with a bit of silicon or 2 rubber washers (one either side) sometimes supplied with the fitting

https://www.screwfix.com/p/compression- ... 22mm/36982

Someone-Else · Post by **Someone-Else** » Mon Aug 31, 2020 10:59 am

Just asking, you have said it will go from a pond to a rill, then presumably back to the pond?
Question, does this pond have any fish?

Oh and pictures would be nice.

ayjay · Post by **ayjay** » Mon Aug 31, 2020 11:00 am

- but he beat me to it.

Something like the outlet fitting for a cold water storage tank would fit the bill.

Bajr · Post by **Bajr** » Mon Aug 31, 2020 5:03 pm

Thanks all three of you for your eminently sensible replies. Much better and more straightforward than faffing around with a solder or glue.
I’ve just got to be careful as there’s a slight curvature to the tank wall - it’s a half cylinder, radius 45cm.
Wasn’t planning on having fish, probably too small. I guess there’s issues of toxicity with the metals?
Photos will follow soon
Thanks again.
Ben

Razor · Post by **Razor** » Mon Aug 31, 2020 8:43 pm

You will almost certainly find the vessel will deform slightly due to the clamping pressure and seal just fine. It's going to be under negligible pressure. If you can't get it to seal there's always the more expensive option of an Essex flange which is made exactly for this:

https://www.bes.co.uk/22-mm-compression ... nge-17541/

wine~o · Post by **wine~o** » Fri Sep 04, 2020 2:35 pm

Razor wrote: ↑Mon Aug 31, 2020 8:43 pm You will almost certainly find the vessel will deform slightly due to the clamping pressure and seal just fine. It's going to be under negligible pressure. If you can't get it to seal there's always the more expensive option of an Essex flange which is made exactly for this:

<span class="skimlinks-unlinked">https://www.bes.co.uk/22-mm-compression ... 7541</span>/

Just a warning, the Essex flange being brass will cause the aluminium to corrode over time (assuming the circular section is the aluminium part)

Copper attached directly to aluminium will also cause corrosion.