Well, my project is almost complete. I added a 3:12 pitch roof which replaced a 3/4:12. Now for finishing touches, I would like to build some arches. The two supporting columns are going to be something like 8×8 permacast columns. But I’m willing to learn how to build my own columns. I would also like to learn how to build arches between columns and the house. I know I will have to build the beams out to 8″ that way the top cap on the column is flush. Any ideas and instruction would be great. Thanks guys.
Don’t know why my pics are sideways. I’m using an ipad
Replies
aspa
Find the pictures and turn them right side up. Unlike your ipad, we cannot turn the computer screen sideways and have them shown right...................
As far as the columns, structural posts need to be just that-and can be covered by any type of material you seem fit to use.
Arches can be made up the same-a "box beam" with the curve and it's bottom and trims-mainly to bridge the distance between the columns-structural like a decorative header or just a dropped curved bulkhead.
Please try to save those pics on your computer and turn them right side up-post from that computer.
Materials?
How would I bend the trim that goes between the arches? What materials what you recommend? Sanded 1/2" plywood, 1x10 pine? Etc.
Ideal for bending is tempered hardboard ("Masonite"), but it's pretty scarce these days. And you wouldn't want non-tempered as it wouldn't stand up to the weather. Depending on the radius 1/4" exterior plywood might work OK.
What kind of radius are you looking at?
Two Support columns are going to be spaced 8ft apart. But I'm a newbie, and haven't figured radius yet. What do you think?
You can drag out the math books to figure radius, or you can cheat: http://www.handymath.com/cgi-bin/rad2.cgi?submit=Entry
(Not that you really need to know radius, but we'd like to know if you're thinking a "tight" radius of a foot or two, or something really broad, like a 16-foot radius, or something in-between. The 16-foot radius is a half foot of arc in 8 feet.)
aspa
I have used "bendable" plywood (4x8) with good success. The plys are oriented so that the sheet bends easily and is not deformed.
Also used various solid stock, kerfed on the backside (same depth and evenly spaced). Too tight a radius and you risk cracking/splitting.
PVC which bends easily and stays if heated prior to bending. (see Azek bending instructions). You can also bend the 3/4" stock easily in a gradual arc. Hold the center of one of the pvc's and you'll see how easily both ends flop down.
In most cases the smoothness of the bend depends on the substrait you are fastening to. If you use just blocks spaced too far apart-there's a good chance the bend will appear faceted. If you fasten to the bottom of the faces of the finished arc or a smooth curved frame within, most of the above products will look real good.
Take a look around ThisIsCarpentry.com for some info on drawing an arc http://www.thisiscarpentry.com/2012/03/30/drawing-an-elliptical-arch/
or perhaps you can scribe what you want using something that evenly bends to make a template.
The second method usually works and involves no geometry.................
How's this?
Thanks for fixing the pictures.
I forgot about PVC, which would be a good choice if you don't want a tight radius. (But note that PVC will twist on you unless you're careful to back it up somehow.)
If you have the time to wait for the material to dry out, it's generally ok with inspectors to laminate framing material with a structural adhesive to the dimensions of the structural post required. After the framing material is glued it has to have time to dry out before the final shape is cut and sanded. No kiln dried wood is not dry - it's still 16% moisture.
Cutting round columns from laminated framing material takes an hour or two per column with a relatively simple router lathe setup made from 3/4" ply. When I need a solid wood column (or mdf column to veneer) it takes about an hour to make the router lathe box and another hour or so to be making wood chips.
As for the arches, what it's made of depends on the look you like. Some situations, like stain-grade work, it's better to laminate thin layers of solid wood. Sometimes plywood is easiest. Personally I like three ply 3/8" for paint-grade stuff - it's fairly thick, yet bends easily in one direction, normally across the sheet.
Forget radius formulas and whatnot. Cut a thin strip of wood and use a lightweight ratchet strap to adust the bend to what looks good to your eye. Nothing beats looking at an arch in place, short of drawing it to scale.
If you want something more fancy than a simple arch, my favorite source of information (and all the formulas you want) is Circular Work in Carpentry and Jointery (or something like that) It's a reprint of a very old book and gives half a dozen ways to get the arch you want. Mine was ordered from woodcraft.
Thanks for all the advice!