Installing SS HERMs coil in HLT

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

I have my heating element installed in my HLT and just did a water test for 2 hours to make sure it was leak free, success.

I am now ready to tackle HERMs coil installation. My coil is 7 1/4" high and I have located the hole placement for lower HERMs bulkhead. I think I am going punch that hole, install and test the bulkhead and then dry fit my coil on the bulkhead. I will manipulate the coil to see if I can get the 2 bulkheads to line up in a vertical line. If it doesn't go well at least I'll be able to locate where the upper bulkhead will need to be placed. I am using street elbows to attach the coil to the bulkheads at 90 deg. to the kettle wall.

More to come......

rosenjm · Joined: 21 Dec 2010 Posts: 249 Location: Ballston Spa, NY

Or you could just cut the end off the coil so the 2 valves end up in a vertical line. Loosing a few inches of length of tubing isn't going to affect its performance any.

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

Installing the coil did not go well. I am having trouble getting it lined up to mate with the compression fitting no matter what I try. It needs about a 7 or 8 degree bend about 3" from the end of the tube but the force needed in that exact location causes a kink, which I have done twice, resulting in another foot or so of tubing lost to the effort.

I got frustrated and gave it for the evening. I am looking again at Kal's pictures. I am not sure at this point rather to continue on with the elbows or attempt a perpendicular connection.........

I work today at my LHBS and I'll ponder the situation some while at the shop.

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

Kal, I think I've asked this before, but what thickness of steel tubing did you use? I got mine on ebay from nybrewer, which is 0.020". I just find it incredible that so many people have struggled with this, yet it was relatively easy for you. I realize you're a capable guy, but surely someone else must be able to repeat what you've done? Maybe your coil was thicker walled, or you have a few superpowers you've not told us about?

**kal** · Posted: Sat Apr 02, 2011 11:42 pm Post subject:

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

Thanks for the details kal - in the absence of superpowers, I wonder if thickness is the key - your tubing is nearly twice as thick as mine, and what I guess others are using too.

When I kinked my tubing, I cut it off - and it looks incredibly thin. I'm no expert, but from a layman's perspective it doesn't seem surprising that it kinks so easily looking at how thin it is. I'm taking a guess here, but I also would expect that doubling the thickness has a non-linear increase in strength, because of the shape, so your tubing could be 3-4 times stronger.

rmessick · Joined: 20 Feb 2011 Posts: 123 Location: Turners Falls, MA

I sourced my coil from the same place as crush and also have the 0.020" wall thickness. I haven't tried to bend it yet, but am spending more time planning the technique as I hear more "kinky" stories. At this point, my plan is to either fill the coil with water or granulated sugar and cap the ends off before trying to coil it (I've done that successfully with copper coil to build my current HERMS coil). For the actual bending, I'm going to build a roller bender like MillWerks described in this discussion: http://www.theelectricbrewery.com/forum/viewtopic.php?p=284387#284387

There has to be some way to bend this thin walled stuff without kinking it (otherwise, they wouldn't sell it). Have others been filling the coil with water or sand or sugar before trying to bend it?

The form that rosenjm used (also discussed in the thread mentioned above) looks very promising, too - did you bend the 0.020" diameter coil with that, rosenjm?

-Dick

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

rosenjm · Joined: 21 Dec 2010 Posts: 249 Location: Ballston Spa, NY

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

Rosenjm's frame is a great idea. For me, coiling the tube wasn't a problem using Kal's foot and hand technique and plenty of zip ties, but bending the ends so that they were perpendicular to the kettle was really difficult and brought out the kinky side of the tubing. I eventually got a good tight bend by pushing a corny keg into the tube, but if you have the 90 degree elbows, I would recommend that.

Nixbesser · Posted: Thu Apr 07, 2011 11:59 am Post subject: Me too

I had the same problem with the SS tubing...Wasted 80 dollars.I went to Lowes and purchased a coil of copper and now life is good. I would have rather used SS as Kal did, his logic is sound regarding the ease of cleaning and durability.

rcrabb22 · Joined: 23 Dec 2010 Posts: 462 Location: Illinois

rmessick · Joined: 20 Feb 2011 Posts: 123 Location: Turners Falls, MA

**kal** · Posted: Thu Apr 07, 2011 3:08 pm Post subject: Re: Me too

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

Dick,

The 0.020" tube is really delicate - just look at it funny and it kinks.

I used the keg as support for the inner side of the tube (the side that kinks when you try to reduce the diameter of the coil). The keg flexes when forced into the tube, but this is good since it distributes the pressure along a section of the tube rather than at a single point.

I did this sitting on the floor - it requires one or two feet to push the keg while you hold the coil fast with both hands.
So, sitting on the floor, coil in front of you, place the keg in the middle of the coil so the coil goes around the keg. Then position the keg away from you to the "back" of the coil, so keg butts up against the part of the tubing you want to bend. Grab the tubing with both hands, with each hand grasping the tubing several inches from each side of the keg, and using your feet, push the keg into the tubing while pulling the tubing towards you with hands to provide resistance. You can pull with your hands a little more than you are pushing with your feet, but not much. The main change in shape happens because the tube is deformed around the keg with continual pressure moving along the tube as it deforms, rather than bending the tube by pulling two parts together, which puts all the pressure at one point.

You use a fair but measured amount of force, increasing kicking and pulling pressure slowly and equally, and you'll feel the tube bend around the keg a little. Reposition the keg and bend further along the tube. The first one or two tries can take 8-15s to get the right force, but once you get a feel for it you can get the bend down to 3-5s before moving along to the next part. (Not that it's a race, but getting to the right pressure quicker seems to give a cleaner shape, and preserve the roundness of the tubing better.)

The keg does flex when you push it into the coil with your feet, but I didn't see any damage. if the flexing worries you, you might try this on an old keg if you have one. perhaps pressurize the keg a little to provide some support.

Always ensure the tubing is in firm contact with the keg by combined pushing the keg/pulling the tube. The tubing kinks with almost no warning, so it's better to use too little pressure initially than too much, with the greater pressure coming from your feet into the keg, increasing until the tube bends slightly. if you continue to use too little pressure, you may not bend the tube, but just "flatten" the inner side. It's a real balancing act on a knife's edge while riding a unicycle..or keg Very Happy

I hope that's clear, but let me know if you need more details!
Cheers,
crush

drbobdc · Joined: 09 Mar 2011 Posts: 7

I wondering if ya'll are being to anal about this coil deal, I'm cheap so I am re-purposing my old IC, it is already in a nice little coil with bends ready to connect to bulk heads. The differences are the bulk head connections are both towards the top of the HLT , no problem, and it is 25' 3/8 od, also should not be a problem as flow restriction and volume moved per surface area should more than make this adequate. At the very worse I could ramp the temp in the HLT until equalization occurs. The guy who sells the SS coils has pre-bent IC in SS that would work nicely... course I haven't tried mine yet but will in two weeks when my pumps show up and right before I install it. It works damn good at chilling so no reason to believe it won't work good as a HERMS coil.

rosenjm · Joined: 21 Dec 2010 Posts: 249 Location: Ballston Spa, NY

Nixbesser · Posted: Fri Apr 08, 2011 12:42 pm Post subject:

rosenjm,
The pictures of your SS tubing looked exactly like mine! Needless to say, a few expletives flew that day.
I too needed to get the diameter of the SS tubing to about 11'' as I'm using keggles instead of the Blichmann kettles.
I would love to have Blichmann however I struggle justifying the cost. Maybe next year...

As I'm still building my control panel, I won't know how the copper works until my rig is finished. If it proves to be troublesome, I may consider Kal's pre-made version if the diameter is tight enough.

On to the control panel build...

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

nixbesser, you'll be fine with copper. Milldoggy and possibly others also used copper, and not heard anything bad from him about it.

If I had to do this again, without getting a ready made coil, I'd either get the thicker SS coil (0.035") or go with copper. As you probably know, copper is good for brewing, and much easier to coil to a tighter diameter. The only reason to go with SS I think is the bling factor, and that it doesn't tarnish.