Cutting notches accurately

[Keith]

I'm building a pergola. I plan on using 16 foot cross pieces that will lay across two by tens sistered to a six by six post.

I've got to cut 48 total notches. I was thinking of using my 2 HP router with a template to cut the notches so that I get the location and depth accurate.

Squaring: I'm not sure as to how to sqaure off the edges as this is 1.5 inch thck stock and if the router idea makes sense.

I do want to note that I am also trying these ideas as a means of building skills like making and using templates.

I've drawn the shape on my PC and I plan to use a printed 1:1 scale of the template. What I'm not entirely sure of is how far back to space for the template following bearing. I know it depends on it's diameter and I cannot recall what I have.

Keith

[Andy Dingley]

Big chunky hand-held circular saw, with the right sort of blade for cross-cutting One of those big Stanley adjustable triangular squares (or similar) as a guide. A honking big wide chisel and something lumpy to hit it with.

Saw the edges of the housing, paying attention to which side the kerf goes. Then freehand cut more cuts between this until you have a load of short-grain wafers left behind. Bonk them out sideways with the chisel and crudely pare the bottom of the housing clean. Use a cheap #78 to clean up if they're wide enough.

Remember to rot-treat the exposed endgrain before asembly.

I really wouldn't want to rout this. Long router bits are horrible things and it would take much longer anyway.

[Keith]

Hi Andy,

I hear you in regards to the large router bits. The circular saw and chisel technique is one that is tried and true and used a lot by the pros.

I think most helpful was the size of the wood chisel. I know for example, that Stanley tool makes carpentry chisels and I have several hammers. I think there is a chisel like this with a guard on top so I don't smash my hands.

Thanks for the quick reply. I just cannot get 16 foot boards into the baseent shop or I'd do it on the table saw.

Keith :)

Andy D>

[Stephen M]

No hand-smashing reqired.

Once you snap off all of the "wafers" you will make a paring cut with the chisel. That is, you will be cutting in the same plane as the wood fibers, not (chopping) across it.

Paring cuts are made with your hands guiding the chisel, not a mallet.

DAGS "scary sharp" to learn how to get your chisel ready for this. As for Stanley, it's not the quality of the chisel, It's the edge that *you* put on it.

-Steve

[Mortimer Schnerd, RN]

Back in my days of working construction, we'd just cut the notches with a circular saw set to cut to the desired depth of the notch. Then you'd just smack the wood between the defining cuts with a hammer. If done smartly enough, the waste wood would break off cleanly leaving you with the notch. You could always clean up the notch to be prettier with a chisel if you needed to but it usually was good enough for our needs framing.

[Andy Dingley]

Pros do all sorts of stuff, some of which you really shouldn't emulate!

Best thing for this job is a timber framer's slick. However they're hard to find and often expensive.

A slick is a couple of feet long and is just by hand. If you cut the wafers thin enough, you can pop them apart with the bevel of the chisel as a wedge, or even your fingers. A slick then gives you enough leverage to get it up into your armpit and pare the surface smooth by leaning on it.

For a softwood pergola, just buy the widest "affordable" chisel you can that's still narrow enough to fit down the housing.

I wasn't aware of that. I thought they made paint can openers, because that's all the one's I've seen lately have been fit for. Personally I barely own any English chisels under 50 years old -- I would much rather resurrect some junkyard dog than buy a modern one, and I get a better result. Where I do buy new ones, they're the weird stuff that someone is hand-making in small batches.

I can, but I wouldn't. If I can't lift the timber one-handed, I'd rather bring the saw to it than try to feed it through the saw.

PS - You'll find two or three simple trestles a great boon for working at this scale. Even more useful than a workbench.

[J T]

Mon, Jan 15, 2007, 9:47am (EST-3) [e-mail] (Keith) doth sayeth: I've drawn the shape on my PC and I plan to use a printed 1:1 scale of the template.

Drawn what on your PC? A template for a notch? Ever think about a framing square, and a pencil? Some of you guys carry this plans think waaay too far.

JOAT I do not have the huge amount of faith needed to be an Atheist.