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How to Make a Paint Can Propane Forge for Blacksmithing

Blacksmithing is both a hobby and a useful skill. I initially planned to forge knives, but smaller projects are easier when first learning.

Learn if blacksmithing is for you.

Learn if blacksmithing is for you.

Making a Paint Can Propane Forge

Making a paint can forge is a great way to learn if blacksmithing is right for you. It allows you to begin blacksmithing without too much time and effort. A homemade paint can forge can be made quickly and easily. Most people will have the necessary tools on hand, or they can be purchased at most hardware stores.

The steps used to make this small forge can be easily adapted to make a coffee can forge. Both paint cans and coffee cans act as an exterior metal shell to protect the insulation and contain the heat of this small forge.

Steps to Make a Paint Can Forge

  1. Prepare the Paint Can
  2. Cut Holes for Legs
  3. Add Legs
  4. Cut Insulation to Size
  5. Cut Hole for Torch
  6. Place Insulation in Forge
  7. Seal Insulation/Apply Mortar
  8. Paint/Protect

Materials Needed

  • Metal paint can (shell of forge)
  • Step drill bit (used to cut holes in paint can)
  • Power drill (for use with step drill bit)
  • BernzOmatic torch (heat source)
  • LP or MAPP gas (fuel for torch)
  • Ceramic wool blanket insulation (forge insulation)
  • Rigidizer (seals ceramic wool—optional)
  • Refractory mortar (additional insulation, sealant)
  • 4-inch bolts x 4 (to create legs of forge)
  • 8 nuts to fit bolts (to hold bolts to forge)
  • Mask, gloves, eye protection (PPE to protect yourself)
  • Paint stirring stick (to spread refractory mortar)
  • High-temp paint (to prevent rust/corrosion)

Step 1: Prepare the Paint Can

Most paint cans have an inner lining that should be removed prior to additional work. Using the hand torch, burn off the lining by heating the exterior of the paint can. Work appropriate PPE and work in a well-ventilated area.


Step 2: Cut Holes for Legs

Stand the paint can upright. If you plan to leave the handle on it, orient it horizontally from your left to right so that the handle is at the 3 o'clock and 9 o'clock positions. Drill a hole about 45 degrees from the 6 o'clock position. This should be near the lip of the can. In other words, drill a hole halfway between 7 o'clock and 8 o'clock. Drill a second hole between the 4 and 5 o'clock positions. Drill a third and fourth hole straight down from these two holes, near the base of the paint can.


Step 3: Add Legs

Thread one nut on each of the four bolts about 1/2 inch. Insert one bolt into the hole you drilled into the paint can. Thread a second nut onto the leg and tighten so that the bolt is secured to the can. Repeat this for each hole. These four bolts should hold the paint can off the ground and keep it from rolling.


Step 4: Cut Insulation to Size

Stand the paint can on the corner of the ceramic fiber blanket. Trace a circle upon the insulating blanket, using the paint can as a guide. Remove the paint can and use the razor to cut out the circle you just drew. Attempt to cut just inside the circle, as the inside diameter is slightly smaller than the outside. Do not worry if it isn't perfect.

Cut a strip of ceramic blanket that is the height of the paint can. You can measure the height with a ruler or tape measure, or use the paint can as a guide.

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Measure the height of the paint can, which should be slightly taller than 11 inches. Mark this on two points of the ceramic blanket. Draw a line with your marker and then cut upon this line. A sawing motion with the razor seemed to be the easiest way to make progress cutting the ceramic blanket.


Step 5: Cut Hole for BernzOmatic Torch

The size of the hole needed will be variable based upon the size of your bernzOmatic torch tip. Drill a hole slightly larger than the torch tip so that it can be inserted into the forge, providing heat. Placement of the hole should be based upon how you are going to be supplying your propane, and how it would be supported. Optimal placement would be at about the 10 or 11 o'clock position but aimed directly downwards.

Step 6: Place Insulation in Forge

I found it easiest to put the circular portion of the insulation into the back of the forge and then add the strip along the side, top, opposite side, and bottom, overlapping slightly on the bottom. This overlap will help support a piece of firebrick that will function as a shelf to place the pieces of metal you will work on. When applying the strip, press the ceramic blanket slightly into the portion of the "feet" sticking into the paint can. These can function as anchors to help keep the blanket in place before you seal it in. Using the plastic blunt end of your marker, poke a hole in the insulation for where the torch will enter the forge. Support the inside of the ceramic blanket while you poke the hole.


Step 7: Seal Insulation/Apply Mortar

If you have it, use rigidizer on your ceramic blanket. Otherwise, you can seal it with your refractory mortar. Using a paint stirrer, or other spreading tool, mix your refractory cement as stated in the instructions. The cement will likely be the consistency of a thick paste or cake batter. Using your spreading tool, spread the cement along the inside of your forge. Take care to cover all the exposed blanket, as well as the inside of the torch hole. Multiple small coats will likely provide better coverage and insulation. Make sure to read and follow any directions on the cement for more specifics. Most mortars will need drying time before you can use your forge.


Step 8: Paint/Protect

Most paint cans are not protected in any way from rusting. If you plan on using this forge for any length of time, you should use a high temperature paint to cover the outside. Spray on grill paint would be my first choice, as it is easily available.

Propane paint can forge for blacksmithing

Propane paint can forge for blacksmithing

Your Paint Can Forge Is Complete!

You have finished your first forge. This forge will work for smaller projects, and figuring out if blacksmithing is right for you. Save any extra cement to patch any damage that exposes your insulation blanket, as well as if you want to build a larger forge in the future.

Forge linings will slowly be damaged and break down, especially if you are using flux to attempt to make pattern welded/Damascus steel or forge weld.

Want something bigger? Try a larger propane tank forge.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2020 Devin Gustus