Carve inside or outside first?

[John Clifford]

Archtop builders- which do you carve first, the inside or outside arch, and why? Benedetto's book says the outside is first. That makes intuitive sense to me, and is the way I've been doing it. I know D'Aquisto started with the inside arch, but I don't know why. Does it matter? Obviously, either way you have to fine tune it on the outside after the box is together.

Thanks,
John

[Jim McConkey]

For fiddles, I was taught outside first. You want the final curves just right before hollowing the inside. If you do the inside first, you might not get a smooth outer curve if you try to hold to your thickness template.

[Randolph Rhett]

The inside arch is harder to see and feel. I don't think I would be comfortable starting there. Outside first for me.

[Brian Evans]

Outside first, unless you are using a copy router or a CNC. Then I think it would be easier to fixture the blank to carve the outside last because the rough carved inside is essentially still flat for mounting purposes on the machine. I do outside first since I carve by hand (with power tools and planes)

[Alan Carruth]

My impression is that D'Aquisto started with the inside because he wanted to get the volume of air in the box 'right', whatever that is. He may also have left the recurve thick and worked on it after the box was assembled; I know he would flex the edge to determine the correct thickness there. If you already have the outside finished it might be hard to fair in, and could already be to thin in spots by his lights. As always, the 'best' way is the way that woks best for you.

[John Clifford]

Thanks guys, that all makes sense to me. I guess I'll just keep doing what I'm doing. I do leave carving the recurve until after the box is assembled, which is also the way Benedetto suggests. But the recurve is "factored in" to my contour plan, so I know I have room for it.

[Brian Evans]

I had another thought. If you start with wood machined to a precise thickness of 1", like I do, its very easy to flatten and mark contours on the top, drill or route, and then carve the outside first. If you start with rough, un-planed wedges it might be a lot easier to leave the outside rough, flatten the inside, carve that to your planned template and then make the outside match. If you've done it a few times and developed the templates to aim for, that is.