Friday, September 27, 2019

Chapman Fermenter - Closed Transfer Modification

The plastic fermenters in my brew room are nearly ten years old and ready for replacement. They still produce a good quality beer but they're not likely to support closed transfer keg filling. Using Co2 to push beer into a keg under pressure without having to rely on gravity solves two problems. Not having to dead lift fermenters out of a fermentation chamber will eliminate back strain. And pushing beer into a keg using Co2 will keep the beer fresher by preventing oxygen absorption.

Low Pressure Test Of Co2 Closed Transfer To Keg

The ported Chapman seven gallon UniVessel Tank with ball valve best fit my budget and needs for a stainless steel fermenter. They are well made and sturdy enough for use in low-pressure transfers. However, a few modifications will need to be made to their lids. The center hole needs to be blocked to seal the tank. Holes for a gas ball lock and thermowell weldless bulkhead fittings need to be drilled.

Co2 Ball Lock and Thermowell Weldless Bulkhead Fittings

Tool List:
  • A spray can of no-stick cooking oil 
  • 3/16 inch drill bit 
  • 1/4 to 7/8 inch step bit
  • 3/8 inch electric drill
  • Ruler, center punch and hammer
  • Channel-lock pliers or adjustable wrenches

Mark Center Of Hole Location And Dimple With Center Punch and Hammer

Cooking oil is a food-safe lubricant and perfect for drilling holes in stainless steel. It is easy to wipe off with a paper towel and remove with OxiClean.

Before drilling the 3/16 inch pilot hole spray cooking oil on the lid at the location of the hole. Apply downward pressure on the drill while quickly turning the motor on and off. This will prevent the drill bit from overheating and dulling it.

Slowly Drill Pilot Hole In Lid

Next, coat the step bit with cooking oil. And slowly use it to enlarge the pilot hole to a 1/2 inch diameter. Wipe off any excess oil and drill shavings from the lid.

Increase Hole Size From 3/16 To 1/2 Inch Diameter

Then turn the lid over and carefully remove any sharp edges using the step bit. Using a slow drill speed and minimal downward pressure of the drill motor. Care should be taken to remove any sharp burrs without making the hole larger than 1/2 inch in diameter.

Fermenter Lid With Gas Post And Thermowell Installed

With the holes deburred and all cooking oil removed the weldless bulkhead fittings can be installed. By hand start the threaded fittings into the holes in the top of the lid. Use a wrench if needed to thread the fittings all the way into each hole. Screw the lock nuts with washers on from the lid bottom. Snug the lock nuts up to the fittings hand tight. Then use a pair of wrenches to firmly tighten the lock nuts and fittings. Avoid over-tightening the fittings at this point. Squeezing the washers too tight may cause the fittings to leak or damage the washers.

#10 Rubber Stopper With 5/16 Inch Bolt, Nut And Washers

Stainless Steel Hardware List:

  • 2 - 5/16 x 2 inch hex bolts
  • 2 - 5/16 inch fender washers
  • 2 - 5/15 inch flat washers
  • 2 - 5/16 inch hex head nuts

To seal the 1 3/4 inch hole in the center of the lid with a #10 rubber stopper. Drill a 1/4 inch hole down through the center of the stopper. Then thread a 5/16 x 2 inch bolt with a fender, flat and lock washer into the narrow end of the stopper. Push the stopper into the center hole from the top of the lid. Add a fender, flat, lock washer and nut to the bolt end and firmly tighten them together. This will compress and expand the stopper in the hole creating an airtight seal.

Modified 7 Gallon Fermenters In A G&E 7 Cubic Foot Chest Freezer

When fermenting a Kolsch style beer using 1/4 inch inside diameter blowoff tubes connected to the gas posts. The 5.25 gallons of wort inside the 7-gallon fermenters left plenty of headroom for fermentation without fear of clogging the blowoff tubes. When fermenting a heavily hopped beer using a larger diameter blowoff tube is a good idea. Just unscrew the gas posts and clamp 1/2 inch inside diameter silicone tubing to the threaded end of the bulkhead fittings. The larger diameter tubing will further reduce the chance of clogging. But as far as this batch of beer goes primary fermentation is nearly done and everything is working out perfectly.

The maximum pressure rating of the Chapman fermenters is 3 psi. Use care not to exceed 2-3 psi when leak testing or using the fermenter under pressure. Failure to do so can cause the fermenter lid to become disfigured. Other than that as per Steve Chapman "The fermenters hold up just fine for pressure transfers, and many other uses."

Thursday, September 26, 2019

Stainless Steel Heating Element Upgrade

High Gravity 5500 Watt Stainless Steel Heating Element

After four years of regular use, I starting seeing small black specks of what I thought were burnt wort at the bottom of the kettle. On closer inspection, I saw that the hard insulator around the heating element was deteriorating. The rubber boot covering the 220-volt wire connections to the heating element had become brittle some time ago. And the electrical tape added as a quick fix didn't appear to be waterproof or safe. It was time to replace the heating element. 

I submitted a service request to High Gravity Supplies describing what happened to the original heating element. That day I received an email from owner Dave Knott letting me know what replacement options were available. The first option would be to replace the original water heater type element with a newer BoilCoil element. This option would require more rework of my kettle than I cared to. Having a removable power cord would make cleaning in place a thing of the past. But it would require drilling a new hole to allow clearance for the taller BoilCoil. Then plug the original hole used by the old element. And drilling holes for the bolts that hold the basket above the BoilCoil.

The second option would be a direct replacement of the original heating element. There would be no extra holes to drill or plug. Just remove and replace it. I decided to go with this option. The newer element design addresses issues with insulator cracking and flaking. It also replaces the rubber wire connector cover with a sturdy stainless steel cover. All of which are improvements over the original design.

The third option was to replace only the heating element. It meant rewiring the replacement element and reusing the original power cord. It was the least expensive option but not the best one. Not without having a fix for the element insulator and connector issues.

Unscrewing The Existing Bulkhead Fitting Was A Challenge

With the necessary parts ordered and waiting to be delivered, the next step was to remove the weldless bulkhead fitting. I gave the kettle an overnight soak of Powdered Brewery Wash mixed with few gallons of 170F/68C water. Hoping the combination of cleaner and heat would make unscrewing the fitting easier.  It didn't. I soon learned how difficult a four year build up of burnt wort would make this seemingly simple task.

Using two large channel lock pliers to grip both ends of the fitting and all the strength I had the fitting did spin. But to unscrew it from the kettle one end had to be prevented from turning. I sprayed both fitting ends with vegetable oil spray. I tried it again but still no luck unscrewing the fitting. Although now it was easier to spin in the hole.

Finally, I clamped one channel lock on the heating element itself and jammed the handles against the kettle wall to keep the fitting from spinning. With the kettle on its side, I cranked down on the pliers as hard as possible. After a few sharp taps with a hammer to help loosen the carbon build up on the threads. The element started to turn while the inside nut stayed put. Breaking the heating element in two in the process because of the force applied while holding it.

After A Few Choice Words And Some Sweat The New Heating Element Is Working Great

Aside from a few small dents on the bottom of the kettle from the channel lock pliers, the new heating element looks and works great. The new design has a stainless steel cover plate to protect the insulator from direct contact with the wort. And a waterproof stainless steel connector cover has replaced the rubber one. At 5500 watts it's a small but welcome improvement over the 5000 watt element that shipped with my High Gravity system as well.

Upgrading the heating element was a bit more challenging than expected. Replacing the old element with the newer version was definitely worth the cost and effort to install it. The entire process took a little over four hours to complete. Including setup and cleanup time needed to get the kettle ready for brewing. The food-safe vegetable oil used to lubricate the holes during drilling cleaned up easily. And checking the kettle for leaks after filling it took another hour. In all the upgrade cost about $120.00. And worth it to keep my brewing system well maintained and up to date.