BSFL Bin Of Hypertufa & Plastic Tub

There's going to be many pictures in this post over a few days so if you happen upon it uncompleted, check back in a day or two. 

For this BSFL bin project we're using a free plastic livestock mineral tub, 17.5" tall x 21" diameter, from the city recycle yard and a hypertufa cement mix to make the ramps for grub migration. Comments for each photo below.

First to mark the ramp lines...

Top of the ramp to be at 16 inches.

A protracter would be nice but none on hand so I cut a piece of coroplast on the chop saw at 37 degrees for the ramp incline.  Construction paper is used for the pattern, two pieces joined with tape and the top mark is made at 16 inches from the bottom of the paper with the seam being the centerline.  My fancy angle tool is laid out and starting incline lines marked.

A straight edge is used to complete the triangle used for the ramp pattern and carefully cut out.

Hard for me to apply the pattern to the tapered inside so it's taped to the outside.  The tub taper decreases the incline a bit but that's ok. A straight sided container would not present this issue. A tape measure is used along the bottom to assure it's even on both sides ...

And a piece of masking tape aligned with the pattern edge carries it on to the tub bottom.

A steady hand could now mark the inside edge but I'm not that good haha! ...

Masking tape is applied following the see-through edge and marked with a magic marker, then tape and pattern removed from outside.

We now have perfect lines marking where to apply the hypertufa mix up to for the ramps.

Using 3/4 inch PVC pipe for the grub fall tube, 17.5 inches tall, same as the tub height.  A hole is cut in the tub bottom to fit the pipe through so 1.5 inches sticks out below since I'm planning on having a stand for this bin.  The top is held in place with zip tie.

Probably not necessary, especially if one uses reinforced portland cement that contains fibers, but I went ahead with a hardware cloth reinforcement grid, cut about one inch shorter than where the top edges of the ramps will be, also held with a couple of zip ties. 

A line is marked one inch from the tub bottom wall all the way around to the ramp ends.  This will help guage hypertufa thickness as applied.

Not sure this will work but was a thought.  Mini trowel made of wood and sanded smooth before applying paste wax.  The groove is exactly one inch from either edge and 3/16' wide, 1/4" deep. I'm hoping it will help smooth the ramp surfaces flat and apply a ridge along the side to keep grubs from falling off while migrating.

That's about it for tub preparation.  All we need to do now is apply the hypertufa mix when I can get to the hardware store for some portland cement.

Random thoughts.  Was thinking of having braided nylon rope through the sides as a wicking experiment but now I think it might be better to have the ends sticking out of holes in the tub bottom.  If it wicks & drips like I imagine it's going to then another mineral tub bottom can easily be used as a catch basin and even install a spigot if we want.  I thought I remembered reading awhile back that Black Soldier Flies would lay eggs around underneath a bin if the liquid was not contained and so we don't want that.    

To be continued...