Walnut Mantle Advice

[Rayban]

I'm working on a fireplace surround and mantel and will be making the mantle out of walnut. Problem is, the mantle needs to be 9 - 1/2 or 10 inches deep, 72 inches long and 2 inches thick minimum. You'll be able to see the top and portions of the bottom. I have a stock of walnut in different thicknesses and widths that are certainly long enough. However, I don't have any that are 9 - 1/2 or 10 inches wide. The thickest boards I have are 8/4 rough cut.

Has anyone tried gluing planks edge to edge as well as on top of each other to get a block thick enough in this length? I could glue like a long cutting board with the boards standing on end-grain but that doesn't exactly give the look I want. I could go buy a slab thick enough to use in one piece but that would be expensive and seems silly since I have around 500 board feet of the stuff in my shop. I'm thinking of planing 4 boards down to about 1 inch thick by 4 - 1/2 inches wide, and then gluing the 4 together to get my thickness and width. At that point, milling a trim band to go around the edges and hide the seams so that it finishes off the slab.

Has anyone tried this and what success or failure have you had? I know expansion and contraction is a concern but it will be free floating off the front of the fireplace surround and only attached near the back. Thanks for any comments, suggestions or words of experience.

 

[Joe Scharle]

I've never been able to successfully glue walnut laminate without the glue lines showing either, so I'd build it as a box with mitered corners.
Your plan should work, but it'll be really heavy, don't you think.

 

[SRhody]

A couple of years ago I pretty much had the same challenges. I ended up making my own moldings and layered (built from bottom up). The covering layer hid all mounting hardware and left enough of a floating space that we never had any issues with wood movement.

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[KenOfCary]

I like the idea of layering it out staggered like Stacey did with different molded profiles (great job Stacey, btw,) but if you go with the built-up solid block idea, there's no need to use good wood in the center core. You could use a secondary wood or build the core as a box of plywood and cover that with 1/2 to 1" thick walnut. That would solve both the weight problem and the wood movement problem as the ply won't be subject to wood movement.

- Ken.

 

[Jeff]

A snowy day is good for hair-brained ideas so here goes...

How about building a flat, movement free core from 2 pieces of 3/4" plywood or MDF glued and screwed together? The 6 sides can then be finished with your walnut wood as appropriate to your design.

http://www.ncwoodworker.net/pp/showphoto.php?photo=68517&title=walnut-mantle&cat=500

An exploded view of the idea.

http://www.ncwoodworker.net/pp/showphoto.php?photo=68518&title=walnut-mantle-view&cat=500

 

[Rayban]

Thanks. I hadn't thought of doing it that way. Since it's exposed on portions of the bottom as well, I could probably substitute on layer of ply with a bottom layer of walnut. Here's what I'm trying to build (provided it uploads...).