Conical Plastic Beer Fermenter

Inspired by and patterened after Beershastas design

This is our conical fermenter. Based on the conical tank from US Plastics, it seemed perfect to do 10 - 13 gallon batches and the price seemed great.
The conical holds 17 gal though it is rated at 15 on the web site. Clearly marked gallon markings on the side, big top opening, easy to clean. Looked like a great place to start, now I just needed to turn it into the Fermenter I knew it could be.

I put the blowoff in the center of the lid instead of the top of the tank because I figured it would geve me a couple of extra inches clearance from the wort. I drilled the hole in the lid with a 7/8" spade bit. Was a little concerned using a spade bit but it cut the plastic beautifully.
Here are the parts for the blowoff. After the initial assembly I decided to go with a 1/2" barbed fitting for the top for the direct feed from my counterfow chiller.
Starting with a threaded 1/2" PVC coupling going to a 1/2" brass close nipple with a hose o-ring over it for the inside of the lid. I found a socket that fit the couplings ridges nicely and it made tightening easier.
Put it though the hole and add another O-ring on the outside
Then I connected the 1/2" PVC threaded elbow to another threaded coupling with a short piece of 1/2" PVC pipe. I finished it off with a 1/2" barb fitting. When the elbow is connected to the brass nipple and tightened it makes a nice airtight seal.
Then I had to do something about the gap between the plastic of the conical tank and the black screw ring the lid attached to.

First I took out the screws holding the lid on. Then, examining the gap between the ring and the fermenter I figured it would take about a tube of silicone sealer to close the gap. After checking a couple of big guy hardware stores for food safe silicone and coming up empty I found DAP 50 year silicone at my local hardware store. Pure silicone and fda approved food safe.

Rough up the ring and the body of the fermenter with sandpaper before applying sealer. Be sure not to roughen anything that will not be covered with silicone.
Lay big beads of silicone around the inside of the upper and lower lips of the ring and press it in place being sure not to line up the screw holes and making it squeeze out of the entire outside and all of the screw holes. Fill in the inner gap between the tank and the ring and press it in and smooth it out with your finger.

Don't try and smooth the silicone around the outer ring and screw holes - just let it harden in globs - much easier to clean up later. Use the whole tube - you want to solidly fill the area between the ring and the tank.

I tried a lot of things to seal the lid and finally settled on rubber foam weatherstripping. Beershasta uses another Frost King product, a solid ridged rubber weatherstrip. I sanitize it with alchohol every time I use it and change it every couple of batches.
I used a 3/4" PVC valve at the bottom reduced from the 2" threaded opening. When I did this I connected a 2" threaded pvc coupling to a 2"x1 1/4" reducer to a 45° street L to a 1 1/4"x3/4" reducer to a short piece of 3/4" PVC Pipe to the 3/4" valve
There were some major pockets in the 1 1/4"x3/4" reducer so I filled them with food safe 2 part epoxy putty and smoothed it out so that it had no nooks or crannies to catch any nasties. I put the 45° in there to make it easier to dump on a relatively short stand. If I had had a higher ceiling in my basement it probably would have been better with a taller stand and a vertical dump
I didn't take any pictures when I installed my racking arm - these are Beershastas originals that I patterned mine after. Its pretty simple - another 7/8" hole about " up from the base, Attach the copper tube on the inside with a compression fitting after bending it to the curved shape. Getting this tube bent without kinking requires a tubing bender. I bought a spring type one at my local hardware store for about $3
I increased the size of my racking tube to 1/2", Beershasta has increased his to 5/8" at this point.
Standard Zymie weldless bulkhead fitting.
My stand is simply 2 pieces of particle board cut with a circular opening and legs made out of some scrap 2x4's and 2x2's
Beershasta is mounting his in a fridge for better temperature control and lagering.
The wort gets into the fermenter from the brewpot through the counterflow chiller, down a 1/2" ID braided vinal tube into the top of the fermenter through the blowoff
Racking off into the cornie is accomplished by attaching co2 to the blowoff and draining through the racking arm into the out post of the cornie. Notice the ease of seeing the yeast cake. As the beer level gets closer to the yeast cake it is easy to turn the racking arm and get the last of it. Under 2 lbs co2 pressure it took about 15 min to fill a cornie. Just attach the black fitting to the out post and open the tank popoff.
Beershastas approach...