Mortar/Concrete Calculation

[jadyn]

I want to set a rotary clothes line ground spike into a builders bucket full of either mortar or concrete and I'd like some advice on the quantity of mix I need.
I think that a standard builders bucket has a capacity of 14 litre and I'd like to know what weight of sand/cement mix I need to fill the bucket to the the top when combined with the water. I don't want to mess around mixing sand with cement to make the mortar as its a one off job so I'm thinking of buying either a bag or bucket of combined sand and cement.
I don't know if it would be better to get a bag of ready mixed concrete for the job. I'll be mixing it all by hand either way. Would I need a different weight of combined sand, cement and aggregate for the job? Would something like postcrete be cheaper?

Thank you

[The Builder]

Postcrete, Jadyn. (Concrete for posts)

https://www.diy.com/departments/blue-circle-ready-mixed-postcrete-20kg-bag/35713_BQ.prd?gclsrc=aw.ds&ds_rl=1272379&ds_rl=1272409&;gclid=Cj0KCQjwhr2FBhDbARIsACjwLo34YdbF-iaQsugO5c32_CS9wxpfRMjDvBt8j6eVn_l3UWMBnMPWW3waAocJEALw_wcB

1 bag is approx. 12.5 litres
Place the spike, stuff the (ready)mix around it, and add water.
Most fencing contractors use it :o)

For the price of it, it's not worth mixing your own.

[sddsddean]

I was going to suggest a bag of 'postcrete' before I got to the end of your post. That will be ideal and cheaper than buying small quantities of cement etc.

[woofgang]

its brilliant stuff....just make sure you have a method of moving it as its quite heavy.

[jadyn]

Thank you all for your advice. I'm very grateful.

[Atheist]

Wolfgang, postcrete is as heavy as dry sand and dry cement. Postcrete bags are (I think) 20 Kgm. One postcrete bag is enough for jadyn's needs.

[THECORBYLOON]

The instructions say to pour water to a third the depth of the hole and then add the dry mix.

[woofgang]

Atheist yes it is....maybe I should have said that ALL solutions are going to be heavy to move?