Are these useful for brewing... or anything?

[brando]

Old mini kegs from McDonalds, used for soft serve ice cream topping flavours I believe. One has a sticker on the side saying "Chocolate".

The pickup tubes sit fairly loose - i.e. the white plastic caps lift easily. So I'm not sure how these things were sealed and pressurised?

Volume about 4L at a rough visual guess.

 

[MHB]

They sucked - the syrup out.
I have 4 of the earlier ones with a diptube and Liquid ball lock post, always thought I should weld a PRV and Gas post mounting on to them but hasn't made the top of the must do list.
I think they are 1US gallon ~3.8L probably plus a bit of head space so 4L was a dam good guess.
Would make a great party keg, have seen a couple fitted up with a tyre valve then you could use one of the bike tyre filler pistol thingies and a gun. A PRV would be a good call.
Mark

 

[Mardoo]

They're a good size for HEX housings.

 

[Benn]

Could be made into a hopback,

 

[Mardoo]

Fantastic idea! Now to source another! Or, wait, abandon the 4L HEX for the 9L from the old copper fire extinguisher...yep, that's what's happening. Thanks! God I love serendipity. Cheers Benn!