I’ve been getting a lot of calls lately regarding “How do I bend a wooden handrail?” Bending handrails, even for some of the most experienced carpenters, causes fear and fear. Well fear not!

Here are some basic tips to get you started:

If the net length of the rail you are bending is 12 feet, a 14 foot bent rail is best to ensure the ends are pulled around the desired radius to maintain their shape when you remove the rail from its clamps. If you have 13 “rungs or steps”, you are safe with a 14 foot bender for an inside radius. If an outside radius goes up a ladder, calculate 2 feet per step. Rail flex is understood when you envision a standard handrail profile cut into thin strips and joined together (tongue and groove joint to create alignment). The bend form must also be included as it is molded into the outside profile of the handrail and is used to sandwich the handrail to allow for clamping without damaging the handrail itself.

Weldwood’s Plastic Resin Glue (a DAP product) is perhaps the ideal glue for bending handrails. It has a 24-hour cure time, allowing plenty of time to bend the rails without feeling rushed. It also sands easily once dry and works on stains. The best place to find this product is a True Value Ace hardware store. I understand they bought the rights to sell this product, which took it off the shelves at every Home Depot and Lowes. It comes in a one pound plastic container and is mixed with water until thick. Apply it to both sides of the bending rail braces, tape or wrap the rails together, and you can start bending!

When considering steam bending, it is best to apply Weldwood after the handrail has been steamed and bent over the forms. Remove it from the forms once it is dry, apply Weldwood and reattach it to the forms. The smoking handrail, for most styles, is not an option unless your bend rail is less than an 18-inch radius. For some handrail styles, the minimum before steam may be a 24-inch radius.

One key to preventing stress points on the rail shoulder from cracking or breaking is to apply vinegar to the stress areas of the wood. The vinegar reacts with the wood fibers to relieve stress. Do not use bleach! Will permanently stain some hardwoods black.

Once a handrail is bent, use an orbital or belt sander to finish the job. Make sure all the glue is sanded down properly, otherwise one will have spots where the stain can’t penetrate as the glue acts as a sealer.

C-clamps or bar clamps are the two best handrail bending tool options.

Also, as a helpful hint, there is a book called “The Stair Builder’s Guide”, by Coffman Stairs, which has a whole chapter on bending handrails (with pictures!). The book is no longer in print, but copies are available. Available through Amazon.com.