# Fabrication of pergola beams



## fortcollinsjerry (May 19, 2009)

I'm making four pairs of special beams for a pergola over my new deck. They will be made out of Redwood 2X12's twelve feet long. Luckly, most of the wood will be going in the scrap pile as I cut away the excess wood sculpting the beams, so in the end there won't be all the weight of the original plank - maybe half (I'm guessing right now).

My delemma is how do I cut the 12 foot inverted cantenary curve on the top of the beam? The plank will be too large and heavy to put it through the band saw and I'm wondering how much trouble it's going to be trying a saber (jig) saw.

Any suggestions?


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## jraksdhs (Oct 19, 2008)

You can try a circle cutting jig on a plunge router. You'd have to first figure out the radius, but it shouldnt be that hard. I'd also use a spiral upcut bit to help clear the chips better.

jason



fortcollinsjerry said:


> I'm making four pairs of special beams for a pergola over my new deck. They will be made out of Redwood 2X12's twelve feet long. Luckly, most of the wood will be going in the scrap pile as I cut away the excess wood sculpting the beams, so in the end there won't be all the weight of the original plank - maybe half (I'm guessing right now).
> 
> My delemma is how do I cut the 12 foot inverted cantenary curve on the top of the beam? The plank will be too large and heavy to put it through the band saw and I'm wondering how much trouble it's going to be trying a saber (jig) saw.
> 
> Any suggestions?


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## Julian the woodnut (Nov 5, 2008)

You'll be just fine using a quality jigsaw, and jigsaw blade.


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## fortcollinsjerry (May 19, 2009)

Julian the woodnut said:


> You'll be just fine using a quality jigsaw, and jigsaw blade.


Looks like a trip to my favorite tool store for a new, more powerful jigsaw. The one I have now is over twenty years old. :thumbsup:

Anyone seen a comparison report on Jigsaw's lately.


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## Julian the woodnut (Nov 5, 2008)

The bosch jigsaw is the way to go. I have two bosch jigsaws that I use for work, building furniture and doing high end trim in houses. They do what they are supposed to, that is to let you do the task at hand with no problems. They are well balanced, and the new quick release button and blade stabilizer work very well.


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## TexasTimbers (Oct 17, 2006)

Our very own Big Dave went down this road too. He was cutting larger beams but I thought I'd link the thread anyway because if you do want to use your bandsaw, his method would enable you to do it, even though it sounds quite tricky I can envisage it being pretty straight-forward. 

But for 2" thick stock I have to agree with Julian, a jig saw will make quick work of it. I too have the Bosch barrel grip and swear by it. I'll never own another D-handle western style jig saw. Well I have a couple but they just gather dust. The barrel grip is like a little sports car compared to the big bulky D-handle style.


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