Question (WOODWEB Member) :
I have a curved jamb to do for an exterior door. Someone told me it's possible to glue many stripes 1/4" thickness in order to easier for bending them and after that, to put veneer on the edge, so the stripes don't show. I think veneer is not going to work for exterior and is better to work with many curved solid pieces, as always the problems are the seams. Does anyone know what the least expensive method is to do this?
(Architectural Woodworking Forum)
From contributor L:
It depends on your equipment. We've got a band resaw and can saw 3/16", then wide belt and glue up on an adjustable form rack. Just use a board thick enough to get all your strips out of and keep them in order. No need to veneer the edge.
If you are not familiar with any of those three, then things will not be inexpensive. The lamination of thinner plies implies a springback that may or may not be an issue. If glued correctly, then the edges are fine - they will not show as laminations. The bricklaid method will have butt joints that show on the inside faces and discontinuous grain. If stained, this may be viewed as a problem. If painted, the joints will still telegraph. As popular as they are, there are a lot of curved head doors out there, and some are pretty poorly made. There is more to it than meets the eye, so be careful. The curved jamb is just the beginning.
Sometimes I see two basic ways to work wood - a large thing cut down to make a smaller thing, or smaller things glued/joined together to make a larger thing - subtractive or additive. Both have their advantages and disadvantages, and some applications may be better than others. Plenty of room for lots of opinion, though. We band saw segments of the curve at the desired inside radius, then add a curved fence to the bandsaw and saw for width. Then we square cut the ends to butt up well, and then stack them on a jig with the radius drawn on it and clamp them to the line. Once dry, the assembly is removed and the facing - usually a 1/8" x a bit over the width - is added with cauls and clamps (per photo above). We have made curved jambs over 12" or wider this way. These can even be fed thru the planer to get to a final width if need be.
Now there are two variations to the above: Sometimes we make our segments over wide and they are roughly sawn to the approximate radius. They are glued up -bricklaid and then the final inside and outside radii are drawn and the assembly goes through the bandsaw again, for final, accurate curves. This is for narrower jamb parts, exterior type with a curve rabbet section and a curved 'fat jamb.' The other method involves the use of the Curvulator - a jig I made for accurate bandsawing of parts, from about 12" radius on up to about 96" radius. This is basically an adjustable center point with two pivoting arms that end in points that will hold the piece as it travels in an accurate arc through the saw. It makes flawless curves with no skill. These can then be bricklaid and faced as in the other methods.