How to Steam Bend Wood

Hi, I'm Jay with Family Handyman. I just got done making a beautiful curved frame for this mirror. Let me show you how to take a straight piece of wood and bend it using only steam. Let's get to it. To start with, you need to make a box to steam the wood in. Here I'm cutting parts to make mine out of plywood, but you can make it out of solid wood, even PVC pipe. Then I cut some pieces of MDF that the bending form will be made from. Making legs for your steam box is optional. I'm making mine so my steam chamber sits just above my steam generator. Here I'm cutting dowels to create an internal shelf to keep the wood off the bottom of the steam chamber. Here I'm drilling the holes for the dowels in the side of the steam chamber. I've ganged the two sides together so the holes align perfectly. Now I'm drilling holes for two thermometers that will go in the top of the steam chamber. Here I'm just using screws to assemble my steam chamber. Remember, it does not have to be perfect. Steam chambers are expendable. Once the steam chamber has been assembled, I'll turn it on its side and insert the dowels that create the internal shelf. I'll cap them with a little CA glue just to keep them in place. A couple of the dowels were a little long, and since I'm a perfectionist, I cut them flush. The thermometers I'm using were actually meant for gas grills and have a threaded neck. I'm just threading the holes to make insertion easier. Now it's time to make my bending form. My frame is only partially round, so I'm drawing the circle only three quarters of the way around the square piece of MDF. To make the circular form, I'm going to bend my wood around. I'm using a circle cutting guide for my router. Now I could cut this by hand on the bandsaw, but using this jig ensures the circle is perfect all the way around. When routing like this, remember to take shallow passes. I only went about a quarter inch at a time. Once the first layer of the form has been cut with the circular jig, I rough cut the second layer on the bandsaw to be flush trimmed with the router. I'm using a two inch Forstner bit to drill holes into my bending form. This will provide space for the heads of the clamps that will help me bend the wood around it. Here I'm making a nice straight cut along the straight grain of my quarter sawn lumber using a track saw. And once that straight line has been established, I'll cut my strips on the table saw. Here I'm adding a door to the end of the steam chamber using a simple hinge. I drill the hole in the side of the box to accept the hose of the steam generator. Using a little glue and some screws from the back side, I attach my bending form to a sheet of MDF. Here I'm attaching some wood blocks that will help anchor the wood strip to the bending form. Once the anchor blocks have been attached, I'll mark the wood strip with a pencil for the bolt hole. I drill the hole slightly larger than the leg bolt I'm using to anchor my wood. Here I'm simply cutting the support strap to the length of my bending blank. Okay, I've got the form ready to go. The steam box is ready to go. I've got steam brewing. I'm going to wait a little while for the temperature inside the box to come up, and I'm going to put my wood in the box for just under two hours. The common rule of thumb for steam bending air dried lumber is to leave it in the steam chamber one hour for every inch of thickness. Since my lumber was kiln dried, I doubled that time just to make sure the lignans in the wood were thoroughly softened. Once the wood is taken out of the steam chamber, you've got to move fast. You've got about two minutes to get it in the form and clamped down before the lignans start to cool. Now as you can see, this really goes well when you have some helpers. I couldn't have done this alone. But now the wood's in the form, I'm going to leave it sit for 24 hours and let this wood cool back down and get used to its new shape. As the wood is being taken off of the bending form, you'll notice it wants to spring back just a little. I've anticipated that and made my bending form slightly smaller than my mirror. I chose to profile my mirror frame with some simple round over bits, but you can profile yours in any style you wish. Prior to staining, I sanded my mirror frame up to 220 grit. One of my favorite wood stains to use is one I make myself. This is iron oxide wood stain. It turns walnut a beautiful dark tone. Once that is done, I top coated with shellac. For this project, I chose an acrylic mirror, not glass. I was worried about the glass shattering. The bonus is I can glue my hanger right to the back of it. And once the mirror is set, I used a little construction adhesive to keep it in place. Well, I think this mirror frame turned out beautifully. And you know, while steam bending has been employed to manipulate wood for literally centuries, it's still in use today. Every guitar or violin you see, their sides have been bent with steam. For more great projects like this, visit FamilyHandyman.com