How to mix mortar with a premix or from scratch?

Mortar is composed of portland cement for bonding, hydrated lime for workability,
and sand for strength and bulk. Mix only as much mortar as you can use in 1 hour;
after that the mortar becomes unworkable.

For a small job, it is easiest to buy ready-mixed mortar, which comes in packages
of 10 to 80 pounds. Mix it with water according to the directions on the package.

For larger jobs, such as building a brick barbecue. it is less expensive to

buy masonry cement, which contains only the cement and the lime. Mix it with clean
builder’s sand in a ratio of 1 part masonry cement to 3 parts sand. You can also
buy portland cement, hydrated lime, and sand separately; mix them in a ratio of 1:1:6.
Masonry cement comes in a variety of colors; if you like, buy pigments for coloring any mortar.

Making the mix 

To prepare mortar, measure out the materials by the pail or shovelful in a wheelbarrow
or on a mixing board made of scrap plywood with planks nailed to its sides. For small
batches, you can use any shallow container, even a garbage-can top.

Blend the dry materials thoroughly, with a shovel, trowel, or hoe; then gradually
add water, working the mix until it is plastic and smooth. Workable mortar should
spread easily, cling to a vertical surface without smearing or dropping, and stay in
place (not flow) while stones or bricks are being placed.

To test the mortar, make a furrow across it. If the furrow holds its shape, the mortar
is the right consistency. If the sides of the furrow slump, the mortar is too wet;
add more dry materials to stiffen it. If the mortar sticks tenaciously to the implement,
the mix is too dry; add water.

Caution: Mortar is a caustic. Wear goggles, waterproof gloves, long pants, and a
long-sleeved shirt. Promptly wash splatters off your skin. Rinse clothing when you
finish working. If mortar gets in an eye, flush with clear water and call a doctor.