Heatsticks Power Distribution Board Action Shots! SNAFU

Heatstick Construction

(This article is spread across three pages that cover the three phases of construction of my electric brewing system: one page for the heatsticks, one page for the power distribution board that powers them, and one page of the system in operation. Use the links at the beginning and end of each article to move through the series. If you came here from the SNAFU website, there's a link back to there.)

Update! (20 Jan 06) After brewing a few batches with my heatsticks, one of them started developing leaks. I built some more powerful heatsticks (four at 2 kW each) for the former local homebrew shop, and we ran into some more leaks. I got most of theirs working by glopping on more silicone, but that seems like a Band-Aid solution. At this point, I'd have to say that the silicone wasn't such a hot idea.

This page with someone else's heatstick project told a similar tale of woe with sticks sealed with silicone. The solution put forth was to pot the business end of the stick in a two-part quick-curing resin. I did that with my heatsticks, but there must've still been some water in them that got trapped by the resin. I ended up rebuilding them with new heating elements and drain pipes, with the resin applied inside and out to seal them up. They've stayed submerged for 24+ hours and then used to bring some water to a boil. I've not had a short circuit yet, and I suspect I won't have one for some time to come.

I don't yet have pictures of the new, improved heatsticks (I need to find my camera first), but I'll describe the changed assembly procedure below. Once my camera comes out of hiding, I'll at least get some shots of the assembled sticks. I'll most likely end up rebuilding the homebrew shop's sticks, so that'll be one last chance to get some updated assembly pix.

I've also designed a better handle that is longer, more durable, and easier to use. You can make the handle in longer or shorter lengths to accomodate brewkettles of different sizes.

One impediment to doing more homebrewing (other than sporadic availability of a local homebrew shop, though that has since been corrected) has been a safe way to do all-grain brewing in the cramped confines of the kitchen of a one-bedroom condo. I bought some turkey fryers at Sam's Club a while back at a decent price (a total of $75 for two propane burners with 8-gallon stainless-steel pots and some other related accessories) and have even used one of them indoors a couple of times. There are a couple of problems with this, though:

Propane burners put out a bunch of excess heat, which drives up the indoor temperature considerably. Your A/C will be working overtime to keep up.
I probably broke who knows how many fire codes by running a propane-fueled turkey fryer indoors. (A cop once told me it's only a crime if you're caught. :-) )

At least I didn't kill myself by carbon monoxide (CO) poisoning. My understanding of the combustion of propane is that it shouldn't produce CO if the mixture is properly adjusted (you want no yellow in the flame); that's why warehouses and stores can use propane-powered forklifts, floor-cleaning equipment, etc. without killing everybody.

Enough about the usage of propane and propane accessories indoors, though; you're here to learn about the application of large amounts of electricity to speed up your brew session and keep the fire marshal off your back.

Some recent discussion of electric brewing on the Homebrew Digest brought up a mention of Pete Calinski's heatstick page. I had run across this before and decided to give it another look. The idea looked sound enough, and I figured I could tap into the clothes-dryer outlet around the corner from the kitchen (240 volts, 30 amps) to safely get enough power to a set of heatsticks. After a few trips to various stores, I had the parts gathered up. I found nearly all of the parts to build the heatsticks and power distribution board at Home Depot; the resin used to seal the sticks came from a local hobby shop, but I've also seen it at Hobbytown USA. This means that all of the needed parts should be available just about anywhere.

Here's a quick rundown of the parts that go into a heatstick. The power distribution board will be covered in a separate page after this. (Clicking any image will bring up a larger version to show more detail.)

120V 1.5kW water heater element:

2-kW elements that also run on 120V are available, too. If you have a 240V 40A (or greater) circuit available to power your heatsticks, you can use these more powerful elements by plugging them into a power distribution board (described in the next page). A 240V 30A circuit is sufficient for four 1.5-kW heatsticks powered through a power distribution board. Three 1.5-kW sticks are sufficient for the five-gallon batches I make, but four 2-kW sticks would be a better match for the ten-gallon brewer.
12' 14/3 (for 1.5 kW) or 12/3 (for 2 kW) SJOOW appliance cord (this stuff is rubber-jacketed and water-resistant; the first number is the wire gauge (14 or 12), the second number is the number of wires in the cable (live, neutral, and ground), and "SJOOW" specifies the type of insulation, jacketing, and other construction details)
heavy-duty 120V 15A (for 1.5 kW) or 20A (for 2 kW) plug (when I went, there were some fold-up nylon plugs available in yellow or orange for high visibility)
15" J-shaped kitchen/bath drain pipe, chrome-plated brass, 1.5" diameter
PVC coupling, to adapt from the drain pipe to 1.5" PVC pipe (solvent weld)
6" of 1.5"-diameter schedule 40 PVC pipe (you might want to go to 12" if you intend to use the sticks in larger kettles, such as a half-barrel keg)
1.5" PVC solvent-weld cap
PVC primer
PVC cement
Alumilite Casting Resin. This is the aforementioned two-part resin compound that replaces the silicone. Get the regular variety, which turns a tan color when it cures. While the other parts should all be available at Home Depot, Lowe's, or other similar stores, you'll need to track down a hobby shop for this stuff (Alumilite's website has a dealer locator). Expect to pay about $30 for a kit that makes 28 ounces; this will be enough for five heatsticks with some left over. This is a little bit more expensive than the RTV silicone I was using before, but it should be nowhere near as troublesome in the long run.
some rubber gloves and tape (the ones I had on hand were made of nitrile instead of latex, and they pulled away from the resin somewhat easily)
some nylon zip-ties

Basic hand and power tools will suffice for assembly: screwdrivers, wire cutters, wire strippers, a fine-point permanent marker (such as a Sharpie), and scissors. A razor blade can be useful in stripping the outer jacket of the power cord, but be careful and avoid nicking the insulation on the wires underneath. You'll probably need a hacksaw to cut the PVC pipe to the appropriate length, and you'll also need a drill and a 3/8" bit.

Disclaimer: I shouldn't have to put this in here, but if I didn't and some numb-nuts got himself killed while trying to assemble or use a heatstick, his next of kin might hire an ambulance chaser to sue me into oblivion. Since we haven't yet heeded Shakespeare's advice to kill all the lawyers, take heed: This project involves wiring parts together that will connect to household power (120 volts AC). If you don't exercise sufficient care in assembly, testing, and use, you could zap yourself. Construction is fairly simple, but if you have any doubts about your electrical-wiring prowess, find somebody who is, or find another homebrew construction project that doesn't involve electricity. While I've assembled three heatsticks and (as of this writing) successfully brewed a 5-gallon batch of ESB with mine, remember that free advice is worth what you paid for it if you're not careful. I'm not responsible for your errors; if you break something, you own both pieces.

With that out of the way, start by stripping away 3" of the outer jacket on one end of the power cord. This will expose the three wires inside (black, white, and green), along with three paper separators that should be snipped off with diagonal cutters:

Strip 1/2" off of each wire. Twist the black and white wires together with your thumb and forefinger so they don't become frayed. (Don't do this with the green wire; we'll want to fan it out later.) Put a 90° bend in the black and white wires, hook them around the terminals on the heater element, and tighten the screws. It doesn't matter which wire goes to which terminal:

Pull the green wire up to one of the corners of the heater element. The cut end of the insulation should butt up against the edge of the hex-shaped part. Gather the three wires together close to the heating element and zip-tie them together. Make sure the ground wire can still reach the body of the heating element.

Unscrew the retaining nut from the J-pipe. Feed the power cord through the J-pipe and slide the nut over the heater element:

(This photo shows a rubber washer between the heater element and the J-pipe, and electrician's tape securing the ground wire. These should not be used.)

Use a flat-blade screwdriver to press the wire strands flat against the heater element, then tighten the nut onto the J-pipe over the ground wire and heater. There should be some gaps through which the resin can flow, but these photos don't show them:

Cut the palm out of a glove to get a patch of rubber about 3-3.5" square. Fold into quarters and snip off about 1/4" of the inside corner so that there's a square hole in the center when unfolded. Poke the heater element through the hole, then tape the edges to the J-pipe so that the rubber is pulled taut around the nut. Put some tape around the heating element so the cut edges don't pull too far away. Put a band of tape all around the J-pipe about 1/2" behind the nut.

Mix up 5 oz. of casting resin (2.5 oz. of each part) in a plastic cup. Stir for about 30 seconds until it gets the color and clarity of hot tea. With the open end of the J-pipe pointing up, pour in the resin. Turn the J-pipe so the open end is now almost sideways (but still angled up a little bit) and the heating element is pointing down, and start tapping on the bend with your knuckles. This should get the bubbles out. The resin should flow down around the threaded part of the heater element to make a tapered seal. Some resin might also work its way up through the threads between the J-pipe and nut.

The reaction of the two parts of the resin during curing is exothermic, so the bend in the pipe will get pretty warm (enough that you wouldn't want to hold it there). The fumes from the uncured resin are also fairly strong, so you should be doing this part of the construction outdoors.

Shine a light down the pipe while the resin is curing. After about 3-5 minutes, you should see a tan blob down the pipe. Give it another 5-10 minutes, then start removing the taped-on rubber. Hopefully, it'll pull away from the resin relatively easily. If it doesn't, give the resin an hour or two to cool down, then remove the remaining rubber with some sandpaper.

On the last heatstick I built, the resin didn't fill in all of the area around the threads. You can fix this by mixing a half-tablespoon of resin and pouring it into the void. The smaller amount of resin can be helped along in its cure with a heat gun aimed at it from maybe 3" away.

To seal the threads between the nut and J-pipe, mix up a half-tablespoon of resin. Hold the heatstick so the heating element is pointing down and carefully pour the resin in a ring around the nut (you probably won't get all of the resin in). If you have a heat gun, you can use it to speed up the cure of this relatively small amount of resin.

Take apart the threaded end of the PVC coupling. Slide the nut and washer over the power cord and onto the straight end of the J-pipe as shown:

(This picture shows a different coupling than is now specified. It shouldn't be on the J-pipe at this point.)

Drill a 3/8" hole in the center of the cap. The power cord will pass through this hole later. Apply PVC primer to the mating surfaces of the coupler, cap, and pipe. Apply PVC cement to the mating surfaces of the pipe and jam the cap and coupler onto the ends with a twisting motion to get the cement evenly distributed. Let the completed handle sit for 15-30 minutes so the cement has a chance to do its job.

About 7-8" from the end of the J-pipe (or further away if you made longer handles), wrap a couple of zip-ties around the cord so that the "blocky" bits are on opposite sides. These will serve as a strain relief.

Thread the power cord through the handle. Jam the coupling onto the end of the J-pipe and hold it in place with the nut and washer. Hand-tighten as far as you can go.

(Before you make a batch of beer with your new heatsticks, I'd recommend using them to bring 5-6 gallons of water to a boil as a kind of "shakedown cruise." Tighten the nut holding the handle on again. When the stick cools down, you probably won't be able to loosen it. This should be a Good Thing, as liquids hopefully won't get past the washer.)

At the end of the cord, strip the outer jacket and insulation according to the strip gauge given for the plug (it can either be molded into the plug, as it was with mine, or it could be on an included leaflet or on the package). Connect the green wire to the green screw, the white wire to the "silver" (usually plated) screw, and the black wire to the remaining (plain brass) screw:

Close up the plug according to its instructions.

Assembly is complete. The resin should be fully hardened. Testing in water should be OK within one hour. Just to play it safe, I'd allow 24 hours before using the heatstick to make beer, but this probably isn't entirely necessary.

If you have an ohmmeter, you can do some simple electrical checks to make sure the stick will work. Measuring across neutral and live (the two flat terminals on the plug) should yield a reading of about 10Ω (for a 1.5-kW element; it'll be closer to 8Ω for a 2-kW element), while measuring between live and ground and between neutral and ground should read ∞. For safety reasons, you also want to make sure that a reading between ground and anywhere on the J-pipe and heater element (that's not covered by silicone) should read 0Ω. If a short circuit should somehow develop, you want the excess power to go through the ground wire, not through you.

Since wort is made up mostly of water, you should always plug heatsticks into GFCI-protected outlets. Kitchen outlets in newer homes should already be so equipped; even the ones that look like they aren't most likely get their power from outlets that are. (To verify this, plug a lamp into an outlet. Press the test button on the nearest GFCI outlet. The lamp should go out.)

Never plug in a heatstick unless the heating element is fully submerged in water (or wort, or mash). If you "dry-fire" a heatstick by powering it up with the element up in the air, it will burn out fairly rapidly.

Each 1.5-kW heatstick draws 12.5 amps when in use. Residential power outlets handle up to 15 amps, and the wiring between them and the breaker box usually handles no more than 20 amps (an older home might be wired for only 15 amps per circuit; check your breaker box or fuse box). Don't try to plug two heatsticks into outlets on the same circuit; you'll trip the breaker or blow a fuse.

If you built 2-kW heatsticks instead, they draw 16.67 amps when in use. Unless your home was built with 20-amp outlets (which is rare), you shouldn't try to run them off your wall outlets. Only plug them into a power distribution board built to deliver 20 amps per outlet.

If you can find two or three separate circuits in your kitchen and you can get to all of them, you could run 1.5-kW heatsticks off of them. That'll work well enough for testing, but it'll be inconvenient on brew day. What you'll really want for convenience is a distribution box that can power all of the heatsticks from a circuit that can deliver the needed power. Other brewers have set up circuit subpanels in their brewing areas (basements and garages, usually) that can feed several heatsticks and other electric gadgets, but I don't have a basement or a garage. The laundry closet is just around the corner from the kitchen, though, and it has an outlet that'll deliver the goods (240V x 30A = 7.2 kW, four times what regular outlets deliver). Construction of the distribution box is covered in the next article.

Heatsticks Power Distribution Board Action Shots! SNAFU