Coiling the HERMS coil has proven to be one of the most difficult aspects of building our brewery for many users (see some of the failed attempts).
What size do I need?
Two sizes are available:
- STANDARD: 15.5" diameter, 7" high (measurements taken center of tubing to center of tubing). Will work in any kettle with an inner wall diameter of at least 16" such as the 20 gallon Blichmann Boilermaker kettles (or larger). The holes in the kettle wall should be 7" apart (center to center), however we recommend you wait to receive your coil to confirm before punching your holes.
- SMALL: 11.25" diameter, 9.5" high (measurements taken center of tubing to center of tubing). Will work in any kettle with an inner wall diameter of at least 11.75" such as the 10 gallon Blichmann Boilermaker kettles or 15 gallon kegs (keggles). The holes in the kettle wall should be 9.5" apart (center to center), however we recommend you wait to receive your coil to confirm before punching your holes.
The ends of the coil extend approximately 2" past the diameter to allow the user to cut to the exact length they need as every kettle will be slightly different. Cut the ends using a hacksaw and file the edges smooth with a metal file so that there are no burrs. If you want to get a nice clean cut, use a stainless steel tubing cutter instead as it will create a perfect cut without burrs.
How does the HERMS coil attach to my kettle?
If attaching to bare kettle walls we recommend following our build instructions and using stainless steel 1/2" compression x 1/2" NPT female fittings. If your kettle already has 1/2" NPT female couplers, use stainless steel 1/2" compression x 1/2" NPT male fittings instead.
First time cleaning
We recommend a good clean with PBW or similar oxygen based cleaner (recirculate with pump through coil, and a light scrub on the outside with a nylon brush or similar - do not use a steel brush or scrubby). Let it air dry afterward. The air dry allows any un-passivated sections of the stainless steel to re-passivate and prevents future rust. Once this is done, your coil will be rust free for life. (Note that the main sources of rust on tooled stainless steel comes from the use of non stainless tooling which deposits rust components into the surface of the stainless, especially around tight bend areas. These can be buffed out and re-passivated, if required.)
- Total length: 50 feet
- Weight: Approx 10 lbs
- Material: 1/2 inch OD 304 stainless steel, 0.035" wall thickness, seamless.
- Ends: Bent at a 90 degree angle to exit straight out of kettle wall, lining up perpendicular with each other.
Visit the official Custom HERMS Coil product thread in our forum.