All the easy stuff is done so now it’s time to go to work. Put release agent on all surfaces of your mold. Put a pipe across the mold and hang the cage in it leaving clearance top and bottom and on sides and ends. (See my previous post on reinforcing for your concrete bench mold.)

I use Quickcrete and if your dimensions are the same as mine it will take one 80# bag and one 60# bag. I add a little Portland cement to make it stronger and easier to finish. Best to use a mixer if one is available.

Mix concrete until it is workable. The less water you use the stronger your concrete will be.

Using a Concrete Mixer

Using a Concrete Mixer

Concrete Ready to Fill Bench Mold

Concrete Ready to Fill Bench Mold

Fill mold till the cage is covered and vibrate by bouncing the mold on the floor.

Filling Mold with Concrete

Filling Mold with Concrete

Vibrating Mold to Settle Concrete

Vibrating Mold to Settle Concrete

Fill the mold to the top and vibrate some more.

Filling Mold to the Top

Filling Mold to the Top

Vibrating Filled Bench Mold

Vibrating Filled Bench Mold

Now you can cut your cage hanging devises loose and get rid of the pipes.

Removing Cage Ties from Bench Mold

Removing Cage Ties from Bench Mold

Finish your work with a magnesium trowel.

Finishing Concrete with Trowel

Finishing Concrete with Trowel

Put in place the threaded inserts. They should be centered 9″ from the end of the bench top.

Inserting Connectors

Inserting Threaded Inserts

Clamp the hangers to the mold so they will stay in place.

Clamping Inserts

Clamping Insert Hangers

Tap the top of the bolt that holds the insert till the concrete works its way around the insert.

Tapping Inserts

Tapping Inserts

Wait until concrete starts to set and finish it with a hard trowel. If you want to sign your work now is the time.

Let set for 2 to 3 days. Turn your work over on boards or foam blocks. Take the nuts and washers off the mold bottom and lift the mold straight up. If the mold gets on the bolts it will scratch the finish. Take the corner bolts out and the mold edges will fall away.

A view of this finished bench can be seen at the top of this website.

Here’s another finished bench, made with a different custom-made mold:

Imagine - Concrete Garden Bench

Imagine - Concrete Garden Bench

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For reinforcing of concrete in bench top I use 3/8″ rebar ( #3) four bars the length of the top and seven bars the width. There should be 7″ between first and second short bars on each end. This will make room for the connecting hardware that will be placed in the concrete as it sets. This hardware is needed to connect the top and legs together for safety.

Rebar for Reinforcing Concrete Bench Mold

Rebar for Reinforcing Concrete Bench Mold

I use cut to length tie wire with a small loop on each end.

Tying Rebar Together

Tying Rebar Together

Pictured is the twister used to tie the bars in place.

Twister Tool for Tying Rebar

Twister Tool for Tying Rebar

When you cut bars to length you should leave about 3/4″ to 1″ clearance from mold. Put some kind of release on all surfaces of the mold and then hang your rebar cage in the mold. It should be in the middle of the mold so you have coverage top and bottom.

Rebar Reinforcing Ready for Hanging in Mold

Rebar Reinforcing Ready for Hanging in Mold

Rebar Reinforcing Hung from Pipes Laid Across Mold

Rebar Reinforcing Hung from Pipes Laid Across Mold

My bench top is 2-1/8″ thick. Do not put release on the rebar because you want it to stick to the concrete.

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I use dense pressed board 1″ thick for ease of carving the bottom of the mold ( top of bench). The top can be either plain or with a carved-in design. It needs to be in profile so it doesn’t stick up too far. ( Hard to sit on those large bumps).

If you use letters or numbers in your design be sure to remember that you are looking at a negative so everything will look backward.

Spraying Paint Over Design on Bench Mold

Spraying Paint Over Design on Bench Mold

Design Ready for Carving

Design Ready for Carving

Carving Design with Power Tool

Carving Design with Power Tool

Using Chisel to Finish Carving Design

Using Chisel to Finish Carving Design

Design Ready for Sanding

Design Ready for Sanding

After carving and sanding your work you should put on several coats of tough varnish or enamel.

Coating Mold with Varnish

Coating Mold with Enamel or Varnish

The sides of the mold I made of straight grain fir and put radius top and bottom with a router.

Sides Cut from Clear Fir

Sides Cut from Straight Grain Fir

Radius Cut in Sides with Router

Radius Cut in Side Boards with Router

Side Boards Clamped Together

Side Boards Clamped Together Before Drilling Holes for Bolts

Mold Sides Coated with Enamel or Varnish

Mold Sides Coated with Enamel or Varnish

Sand your work and put on several coats of varnish or enamel. I use hangar bolts to fasten sides to the mold. You can use the same bench sides for any of your benches.