Introduction: Hot Pipe Wood Bending

By tomatoskins
About: My name is Troy. I'm a Mechatronics and Aerospace Engineer. I make things out of wood and electronics and spend time outdoors (especially SCUBA diving).

I've always been intrigued by bent wood. However, I can't afford a steamer nor do I have space to store a steam box. I came across this technique in an old issue of American Woodworker (now shared online here). Instead of placing your wood inside a steam box, you soak your wood overnight then create steam inside the wood by the use of a heated pipe. It's a quick process that produces surprisingly great results.

If your already have a torch and scrap wood, you have 90% of the required materials for this hot pipe bending jig.

Step 1: Tools and Materials

Materials:

Tools:

  • Saw
  • Drill

Step 2: Remove Pant From Pipe

Using some sandpaper remove the paint from the black iron pipe. To be safe, I'd suggest not using galvanized pipe for this application as if it is heated too hot, it can release toxic fumes. For this process your pipe should never get hot enough to produce these toxic fumes; but again, just to be safe.

Step 3: Create Torch Rest

Cut pieces for the torch rest from scrap wood. I had some old MDF tha had been run over by my car (notice the tire marks). Secure the supports in place with screws.

Step 4: Cut Front Support and Position Hole

Cut a hole in the center of the front board two inches from the top. This will be where the end of your torch comes through. Position the front and secure in place.

Step 5: Attach Flange and Pipe

Using machine screws and t-nuts, attach the flange in place. I opted for this instead of wood screws because I didn't want them to tear out over time. I was missing one t-nut but I will add that in place later.

Step 6: PVC Torch Clip

Cut a ring from a piece of 4 in. PVC. Cut about one fourth of the ring away. Cut the profile on a piece of scrap wood that fits in between the supports then attach it to the jig with screws.

Step 7: Setup

Clamp the jig to your workbench, you don't want a hot pipe and torch to fall or move while using it.

You want the temperature to be as low as it can be with propane. The flame should just be coming out the end of the pipe as shown in the second picture. If it's loud and shooting straight out the end of the pipe, it's going to be too hot and will burn the wood.

Step 8: Bend Wood

Soak the piece of wood you are interested in bending overnight. I haven't tried anything over about 1/8 in. thick. Press the wood against the hot pipe. After a few seconds you should feel the wood weaken and start bending. Remove the wood from the pipe every 5-10 seconds and dip or spray the wood with water. This will introduce more moisture in the wood and keep it from burning. Bend the wood to whatever shape you like or need. I bend this piece of walnut into two loops. I was surprised at the ease and efficacy of this process.

What bent wood projects have you created? Have you tried hot pipe bending before? Share your stories in the comments!