Bracing the top: preparing and glueing the braces

I prepared the braces for the top by making a series of ‘sticks’ (as my better half calls them). I used a piece of spruce that was wide enough to make all the braces and as tall as the tallest brace. I made sure it was quarter sawn for maximum strength and stiffness.

I started by planing the bottom of the spruce piece flat. Then I creating a perpendicular side using the plane by laying it on its side on the workbench. Using a band saw, I sawed a brace off the spruce piece, taking it off the side I’d just planed. The sawed edge on the brace was planed flush, resulting in a brace (a stick) with three smooth sides. The top of the brace didn’t really need to be flush, but had to be reasonably flat as this was going to be carved to shape later on. To make the next brace, I planed the the newly exposed edge of the spruce piece and sawed off the next brace. I repeated these steps until I had a stack of braces (‘sticks’):

The spruce braces for the soundboard

The spruce braces for the soundboard

The glueing surface of each brace had to be perfectly flat. Only the lower cross brace curves up slightly at each edge. This is to give the top a slightly domed shape. Apparently, not doming the top gives it a slightly concave appearance. I’m not sure if this step is performed just for aesthetics, or if doming the top also has advantages for the sound and strength.

Since the fan braces pass over the bridge plate, I used a chisel to carve a slot in each brace and made sure they fit snugly before glueing:

Shaping the fan braces to fit over the bridge patch

Shaping the fan braces to fit over the bridge patch

I glued the cross braces and the fan braces down first. For the fan braces I used a home made ‘go bar’ deck. This was made of two planks separated by four long screws. The go bars themselves were made of thin wooden slats:

Glueing fan braces with a go-bar deck

Glueing fan braces with a go-bar deck

In my next post I’ll be glueing the remaining braces and doing some carving.

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4 thoughts on “Bracing the top: preparing and glueing the braces

    • it was shop made: two wooden planks separated by four long screws. this works fine if you’re glueing onto a flat surface, although if you’re going to glue braces into an archtop you might need to come up with something clever to place the arch onto while glueing the braces. For a flat top this works fine, although i recommend doing this _before_ glueing in any arched braces…

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