Cedar Window Box Fabrication - Woodworking Talk

bookie203 · 06-09-2008, 02:16 AM

Want to make some window boxes out of cedar for a local customer I have. What is the best way to join some cedar planks together to support that kind of weight? Should I use screws, or maybe just some brad nails with gorilla glue?

Also how do I best protect the inside of the window box from rotting? Is there something I can do to prolong the life of the box? Thanks for your comments.

joesdad · 06-09-2008, 08:34 AM

A good locking miter joint and some water-proof poly glue like the one you mentioned would work. Window boxes need to stand up to the weather and constant pressure of 20lbs (guessing) of wet soil constantly putting pressure on the joints outward. If you want to skip the fancy joint and just fasten face to edge, I'd recommend stainless steel trim head screws and the glue. I'd allow some sort of exit for the water though, not just a couple weep holes, they'll just plug up.

My father built a couple window boxes out of red cedar about 25years ago that were hanging beneath the windows of his shop. They finally fell apart this past year...not bad eh? They got a lot of sun exposure vs. a shady location that would have rotted out a lot faster.

cabinetman · 06-09-2008, 08:36 AM

It would be easy for woodworkers or furniture makers to over think the process. The window boxes I've seen locally are made simply and very quick, using Cedar, Cypress or Redwood. They are usually just nailed or screwed with galvanized fasteners, some are even air stapled or pin nailed. Exterior glues like epoxy, Gorilla glue, or TBIII could conceivably be used.

For interior protection, formed trays are used and some are fiberglassed. I would guess an epoxy based coating could also be used.

Big Dave · 06-09-2008, 09:19 AM

I made some window boxes once for a customer and used the methods described by Cabinetman. I told the customer though that they would last longer and look just as good if they would put smaller flower pots or boxes inside and put the plants in them. From the road they look just as good and once the flowers have bloomed and covered the top of the box you'll never know what is inside anyway. Some even put fake flowers in them so they don't have to maintain them. It's easier to clean out for winter also. Just grab the flower pot or box and pull out of the wooden one.

bookie203 · 06-09-2008, 10:20 PM

Wow, you guys are good. I appreciate the quick responses and the help with the window box info. I've made several out of PVC and used PVC glue which fuses it like nothing else. I've been interested in making them out of wood, but not sure how to fabricate them so they would be strong. Thanks for all the info. I feel better now about trying to make some of these and not worrying about them falling apart in a few months under the stress.

Gerry KIERNAN · 06-10-2008, 12:13 PM

Hi bookie

Welcome to the forum. If you want to place something inside the window boxes to keep them from rotting the plastic window boxes would work well. If you find you can't get plastic trays the right size you could have galvanized metal trays made up at a local sheet metal fabrication shop. This might cost more, but it would work. The other possibilty is to buy some uv resistant roll plastic like they use for greenhouses, and line the boxes with that.

Gerry