VermiTec Weblog

The weather has turned bitterly cold but the worms are happy. It’s not Hawaii for the them but the bin temps are in the preferred range of the worms.

The OSCR plans call for an electric heat cable but I felt that there was too much material in the bin that’s potentially combustible. Paper and cardboard make up a good portion of what we feed the worms. These materials are normally wet, but we have seen them dry out and we didn’t want to take a chance. So, we decided on installing a hot water heating system.

We felt that a 5 gallon plastic bucket would be sufficient water to circulate and the buckets will take temperatures that are pretty high. We started out with an aquarium heater in the bucket but it didn’t heat the water very fast nor very hot. We found the following on sale at our local Southern States:

We happened to have a high volume aquarium pump that we planned to use for brewing vermitea.

We bought 9′ of heavy wall plastic hose. There was no specific structure in the plans to accomodate the hose. We wanted it to be stable and still allow the contents of the bin to continue to settle without hangups. Here’s what we came up with:

securing the heating system in the bin

We attached a 1×3 at each end of the bin and drilled holes to hold 1/2″ emt pipe. We drilled two holes in the bin so that the hose could be inserted just under the emt.

This is what it looks like from an end view:

We then secured the hose to the emt with electrical ties:

The hoses were attached to the pump after drilling holes in the lid of the bucket as shown here:

This is what it looks like after adding some insulation and an electronic thermostat:

The thermostat has a probe. A hole was drilled in the bin to insert the probe which was positioned in about the middle of the bin between the emt pipes. As the contents of the bin have settled we have had to dig around a little to raise the probe a couple of times so far. We don’t want the probe to go too far down or we won’t be taking readings in the right area.

The heating system has been working well. The outside temperatures today are in the teens with wind chills around zero. The thermostat is set at 70 and the compost thermometer is showing temps in the 60’s. The probe’s reading fluctuates around 70 within a degree or two at most.

We are very happy with the heating system. If we build another bin in the future, we will likely make some minor changes with the design.

Back again …. Other modifications made on the OSCR plans were to line the bed with black plastic. Again, I had read that the wood rotted out after a few years of servce for others. Plastic is cheap, much cheaper than replacing the wood in a couple of years, not to say anything about the hassle.

I wanted to preserve the wood as much as possible and found 3/4″ washers that would fit over the emt pipe. They are sold by the lb at our local Tractor Supply. The washers cost me about $5.00 plus the cotter pins of about $1 as shown in this picture:

Use of black plastic to line the bin and use of washers and cotter pins on emt pipes

The plans call for a lot of ventilation holes. I’m guessing that my perfectionism caused me to search for alternatives to the cheaper window screening recommended to be installed over the vent holes. I found 2″ and 1″ aluminum siding vents (louvers) with screens online. I bought some. They were about $1.50 each plus s/h. Here’s a photo:

Aluminum Siding Vents with screens

I used the sliding action noted in the plans. These vents are 2″ diameter. 2.25″ holes were drilled into a 1×4 and into the plywood of the bin. The vents are held in the 1×4 with screws though there’s not much of a lip and a couple fell out until I tried a couple of times to secure them.

It turns out that the bin lid is open most of the time so the vents don’t do much. I have the bin in my garage for now. When I put it outside the vents will become more important.

The final step was to apply paint. I picked up a gallon of primer and a gallon of latex paint at Lowe’s. I chose the color ‘taragon’ as you probably noted from some of the pics. The only thing I’ll say about painting is that putting on two coats of primer and two coats of paint to the inside and outside of the bin takes a LOT of time.

The next installment will be about heating the bin. I’ll get to that hopefully in a day or two.

Oops! I wanted to add a picture of the tek screws so here it is:

tek Screws in emt pipe

And, a tek screw added to each pipe OUTSIDE of the bin to be used when I build a crank handle to turn the pipes -

OSCR Bin showing emt pipes with tek screws

Sorry, it’s hard to see. I’ll take some closeups. More later ……

In October 2009 I decided to build an OSCR bin. I had purchased the plans months before but never had the time needed to work on it. I’m glad that I had time because it takes a LOT more time than one would think it would. In all, it took me part of a three week period. I worked on it whenever I had time. I estimate that it took about 70 hours in all.

Basic Bin, not yet finished