How It's Made: Copper Coil Alcohol Heaters - A (as an anarchy symbol) Guide v1.2

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Guide_to_Building_A_Copper_Coil_Alcohol_Heater_2022_v1.2.pdf

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---- Last updated 2/23/22 ----

Table of Contents

Introduction

What’s up nerds. This digital zine covers our upgraded copper coil alcohol heater build process with various improvements to make these heaters more efficient.

That's Real Hot

A complete heating kit will include:

Current cost: approx. $10 per heater

Improvements @ v1.2

This build of the alcohol heater incorporates the following improvements:

Tools You Need

Materials You Need

How to Build the Copper Coil Jar Burner

Prepare Copper Coil

  1. Measure and cut copper coil
    1. Using a bandsaw (or a hacksaw with a good metal blade), cut a piece of copper tubing to about 10 inches in length for the heater’s coil.
  2. Sand and file the coil’s ends
    1. With a belt sander, press each end of the coil against the sandpaper to smooth the tip.
    2. Then on the top of the belt sander, roll the edges of each of the coil’s ends to create tapered ends.
    3. Check the ends of the coil are clean and smooth.
    4. Alternatively, you can use a hand file or sand paper (60 grit should be fine). Figure 1
  3. Fill the coil with sand
    1. Put on gloves and wear your respirator. These will protect you against the fine sand in the air.
    2. Seal one end of the coil with painter’s tape
    3. Flip the coil over, and pour sand by hand into the coil.
    4. When full, seal the other end with painter’s tape.
  4. Bend the coil into coil shape
    1. Prepare your space to bend the pipes.
    2. Secure a sturdy 1” diameter dowel or similar object in a vice or similar supporting structure.
    3. Stand the coil against the dowel (see photos below) with the center of the coil resting against the dowel.
    4. Be patient – do not rush these steps.
    5. Push the coil’s ends inward against the dowel (see the photos below). The coil is stiff so push slowly.
    6. Bend the coil into a complete loop as shown. Figure 2
  5. Remove sand from the coil
    1. Put the coil over a box and remove the painter’s tape off the ends.
    2. Loop the coil around one of your fingers and carefully tap it until all the sand is out. This takes a while.
    3. If you think you have it all out, continue tapping it a little more to be sure.
    4. Use an air hose to spray the remainder of the sand out.
  6. Drill lids
    1. Using the ends of the coil, mark the entry points on the jar lid where you will need to drill. You can use a Sharpie marker or something similar. For “Pur” lids, you will drill through the “u” in the “Pur” and then the middle of the ___/___/___ at the bottom of the lid as shown below. You do not need to be exact as the coil can still bend.
    2. In your drill, insert and secure the 15/64” drill bit.
    3. Drill two holes through the lid. If you are using a hand drill, put some scrap wood under the lid so you can drill down safely.
    4. Go slow, let the drill cut the lid for you.
    5. [Optional] Using a pair of needlenose pliers, pull off the little tag(s) left under each cut hole in the lid. Figure 3
  7. Drill the fume hole in the coil
    1. Using a screwdriver, spread out the coils to give your drill easier access to the point at which it will drill the fume hole.
    2. Using the center punch, mark where the fume hole will be drilled in the coil. As shown below, this is at the midpoint of bottom of the center coil, facing upward. Push the center punch down until you hear a click.
    3. Insert and secure the 5/64” drill bit into the drill.
    4. Put a piece of scrap wood on either side of the coil and secure the coil in place under the drill.
    5. Line up the drill with the center punch hole.
    6. If using an electric drill, start it in slow speed and cut the hole in the coil as shown. Don’t force the hole, let the drill cut it.
    7. If using an electric drill, always shut it off when done.
    8. Using a pair of pliers (such as channel locks), push the coil together again to undo the spread you made with the screwdriver. Figure 4
  8. Solder the tube to the jar lid.
    1. Wear your respirator.
    2. Cut 2” of solder from the spool for each hole in the jar lid (two cuts).
    3. Wrap each piece of solder around one of the coil tubes that will go into the jar lid, slightly above the point at which they will go into the jar lid. Figure 5
    4. Slide the coil ends through the holes you made in the jar lid. Leave a little space between the solder and the lid.
    5. Secure the coil and lid between two scrap wood blocks as shown. Figure 6
    6. Turn on your propane or butane torch – keep the end pointed up. Otherwise you risk melting the lid seal.
    7. Touch the flame to the curve of the coil over the solder – do not apply the flame to the solder itself.
    8. The solder will bubble. Remove the flame immediately, and wait for the solder to settle. It should appear as shown below.
    9. Repeat for the other piece of solder. Figure 7

Prepare Jar

  1. Prepare wick and insert it into coil tubes
    1. Cut two 7” lengths of wick from the wicking material.
    2. Wet one end of each wick and twist it into the coil as shown. It takes a bit of time and effort.
    3. Keep twisting – eventually it will break free of the edge and slide in.
    4. Slide each wick in about 2”. The wick will get stiff and resist you when it hits the top of the coil.
    5. When both wicks are in place, put the wicks in the jar, lay the lid on the jar and screw the jar lid on tight to secure it. Figure 8
  2. Apply duct tape insulation to jar.
    1. Cut two 7” pieces of duct tape. This length varies depending on the size of your jar. You want to cover the jar completely except for a small open space with which you can see how much fuel remains inside.
    2. Wrap one piece of duct tape around the top of the jar, and the other piece around the bottom so the entire jar, except for the exposed space, is covered. Figure 9
  3. [Optional] Burn test
    1. Fill with your choice of fuel and screw the jar lid on tight.
    2. Place a dollop of hand sanitizer on the lid and light it.
    3. The sanitizer should burn off and the flame from the tube should be constant.

Prepare Safety Enclosure and Mesh Heater Cup

  1. Prepare the safety enclosure which will cover the jar and flame
    1. With side cutters, cut a mesh rectangle 8" x 16" in size, while leaving one of the 8” ends with its ends/teeth exposed as shown in the illustration below.
    2. On the bottom 16” end of the mesh rectangle, cut in the spaces indicated by the red Xs in the illustration below. These will make the feet that let the safety enclosure stand on the base. Diagram
    3. Next, you will need to bend the teeth on the 8” end inward 90 degrees, and the cells you snipped on the bottom 16” end outward 90 degrees.
    4. Put down two pieces of scrap wood on a bench and lay the 16” end with the cells you snipped on it, with the 8” end with the teeth exposed facing to the left.
    5. Using needlenose pliers, bend each snipped wire on the 16” side downward 90 degrees to make the enclosure’s foot.
    6. Next, put a terra cotta pot on the bench. Bend the mesh around the terra cotta pot. (The enclosure’s foot should be against the bench.)
    7. Lift up the mesh while holding its shape. Bend it slightly so the 8” end with the exposed teeth is one square over the other end.
    8. Using needlenose pliers, bend each tooth inwards to secure the 8” ends of the mesh together as shown. (This is tedious, be patient.) Figure 10 Figure 11
  2. Wrap the safety enclosure in aluminum foil
    1. To reduce the effect of the wind on the flame coming from the fume hole, wrap the top 2/3rds of the top mesh cage in aluminum foil, leaving a slit on the side where you can see the flame through the safety enclosure. Figure 12
  3. Prepare the mesh cup in which the jar will rest
    1. With side cutters, cut a mesh rectangle 2" x 10" in size, while leaving one of the 2” ends with its teeth exposed as shown in the illustration below.
    2. On the bottom 2” end of the mesh rectangle, cut in the spaces indicated by the red Xs in the illustration below. These will make the feet that help you secure the mesh cup to the base. Diagram
    3. Next, you will need to bend the teeth on the 2” end inward 90 degrees, and the snipped wires on the bottom 10” end outward 90 degrees.
    4. Put down two pieces of scrap wood on a bench and lay the 10” end with snipped wires on it, with the 2” end with the teeth exposed facing to the left.
    5. Using needlenose pliers, bend each snipped wire on the 10” side downward 90 degrees to make the cage foot.
    6. Next, put the jar on the bench. Bend the mesh around the jar. (The mesh cup foot should be against the bench.)
    7. Lift the mesh off the jar while holding its shape. Bend it slightly so the 2” end with the exposed teeth is one square over the other 2” end.
    8. Using needlenose pliers, bend each tooth inwards to secure the 2” ends of the mesh together as shown. (This is tedious, be patient.)
    9. Press a board on top of the mesh cup to flatten and level the feet.
  4. Caulk the 2” x 10” mesh heater cup to the base
    1. Using the knife, cut the tip off the end of the silicone caulk tube.
    2. Using the punch included on the caulking gun, puncture the foil seal inside the silicone caulk tube.
    3. Put the mesh cup in the center of the base.
    4. Caulk a solid bead on the mesh cup’s feet.
    5. Pick up and put down the mesh cup to smoosh around the caulk.
    6. Use a gloved finger to spread the caulk evenly.
    7. Let the caulk sit and cure – takes about 30 minutes. Figure 13
  5. Place the terra cotta pot on top of safety enclosure.

Complete the Burner

How to Use the Copper Coil Jar Burner

  1. Remove the safety enclosure to expose the copper coil.
  2. If the heater has been used before, use a rag or tissue to clean the soot off the coil.
  3. Fill the jar with your available grade of alcohol (91% preferred), and reseal the lid.
  4. Put a dollop of hand sanitizer under the coil on the lid.
  5. Put the safety enclosure and terra cotta pot back over the coil.
  6. Slide your lighter in the exposed side of the safety enclosure and light the hand sanitizer.
  7. Remove the lighter and wait. The coil should produce a flame.
  8. Wait until the hand sanitizer has burned away. The coil flame should continue for hours, depending on the grade of alcohol you used.

Heater Safety

Diagram

Set up the heater on a flat stable place near the center of the tent or structure with nothing immediately above it. The flame is mostly contained but can still flicker out of the vent at the top of the terra cotta pot. It should not be left burning unattended. It will extinguish automatically when it runs out of fuel or is tipped over, but it is still an open flame and still should not be left unattended.

Store your extra fuel away from the heater itself. It’s optimal if you can put it in another tent or location entirely, but if not make sure the alcohol bottle cap is securely tight and put it as far from the burner as possible.

The heater can be left to burn for hours without any issues as long as you respect which parts get very hot – the jar lid and the terra cotta pot. The heater can also be used more efficiently in short 15-30 minute burns, then blowing it out and letting the terra cotta pot contain and radiate heat for about 15 minutes before relighting it.

HOT:
The metal jar Lid and terra cotta pot will get very hot as shown in this diagram. The pot heats up like an oven dish to a few hundred degrees. Touch it only with proper padding. OR simply do not touch either of these parts for 10-15 minutes after putting out the flame.
The copper loop gets very hot but cools very quickly. It will only stay hot for about 2 minutes after which it will be cool enough to touch.

WARM:
The Jar itself will get very warm or even hot as it picks up heat form the metal lid but cools down in about 5 minutes. However, it only heats up where there isn’t fuel. The liquid alcohol will act as an insulator and the glass around it won’t get hot at all. The bottom of the jar will stay cool.

COOL:
The safety enclosure stays cool to the touch. You can use it to carefully pick up and move the terra cotta pot if needed. The base used stays completely cool and can be used to carefully move around the hot heater unit if needed.

The hot copper burner has been tested as to whether it poses a hazard after it goes out by putting the hot copper part in contact with a variety of flammable paper types and alcohol fumes immediately after extinguishing the flame. Nothing ignited or smoldered. The burner appears to cool too quickly. As long as nothing touches the open flame, the risk of starting a fire is very low. It can still burn your skin right after the flame goes out, though.

Carbon Monoxide (CO):
As with anything else with an open flame, these heaters emit carbon monoxide, which can be poisonous at sufficient quantities. We've tested these heaters for carbon monoxide emissions in an enclosed backpacking tent and in the cabin of a small car. With 91% isopropanol as fuel, CO levels never exceeded 25ppm in either of these conditions, well below the 50ppm workplace continuous limit set by OSHA. Based on these results, we believe these heaters to be generally safe, but it's a good idea to make sure there's at least some ventilation.

Maintenance

Soot:
As you burn isopropyl alcohol, some powdery soot builds up on the copper coil. The lower the alcohol rating, the more soot seems to accumulate. While this isn’t dangerous, it can prevent the flame from heating the copper as efficiently, resulting in a smaller flame. When the coils is cool, clean this off with a tissue, paper towel, leaf, stick, or similar material.

Fuel:
Isopropyl alcohol is mixed with water. 70% has about 30% water. 91% has about 9% water. As the fuel burns and gets lower, the concentration of water increases, so the flame seems to get smaller as well. It will go out when there aren’t enough fumes to sustain the flame. When refilling, we recommend you dump out the old fuel and add fresh alcohol if the flame is weak.

Wick:
If the wick falls out of the copper tube inside the jar, twist it back in as we described in the Build section of this zine. If it happens more, get a thicker piece of cotton rope to replace it. If the wicking material is thick enough, it won’t fall out.

Figure 14 Back to Top