I have to make a custom Redwood Fence. The posts are 4×4 PT wrapped in Redwood, with an external measurement of about 5×5. The design the customer selected has an additional wrap around it at the cap area of another 3/4 stock, so the overall thickness is about 6.5 x 6.5. The cap is oversize and there is some crown molding whic makes the transition to 6.5″. Overall size of the Fence Cap would be about 8×8 or greater.
Simple pyramid design, but low angle, about 15-20 degrees. I can’t make this on my table saw; my jointer is only a 6 incher. I do have a band saw. The home center has simple 4×4 caps which won’t fit this design.
Any suggestions on how to make them?
Boris
“Sir, I may be drunk, but you’re crazy, and I’ll be sober tomorrow” — WC Fields, “Its a Gift” 1934
Replies
If I understand your question, I remember Norm doing something like this a few years ago. He screwed the cap to a long board. Tilt the TS blade to the necessary angle and run the board against the fence. This cuts the bevel on one side of the cap. Rotate the cap on the board 90 degrees and cut again. Four times and the cap has a pyramidal shape.
My table saw is only 10" and the blade won't go that deep. Deep bevel cuts on a table saw scare the bejesus out of me. No way.
I am thinking along the lines of making a sled to attach to the miter guage slot on my bandsaw where it tilts about 22-30°. Then tilt the table another 45° and that gets me pretty close to where I would want to be.
Cut a block of redwood, like 8x8x5, and bevel the four sides on the bandsaw; clean it up with a belt sander.
Thats all my weak brain can figure out at this point. The lumberyard and fence supplier don't have the size I need.Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Make a small sled for the band saw. Attach a shopmade fence to the sled, set at a 70-degree angle to the table. Screw and glue an 8" long stop block to this fence, perpendicular to the table, near the trailing edge of the fence. Set your 8x8x4 block on the fence - it will be leaning 20 degrees away from the blade, just in front of the stop block. Clamp the piece against the stop block and run it through the saw. Rotate 90 degrees and repeat until you've cut all four sides.
Not sure what kind of shoulder your caps are going to have. You could cut a simple shoulder on the band saw or the table saw prior to sloping the tops.
Ah Ha! Yes, I knew I was on the right track. I like the idea of the fixed 70° sled and the stop blocks. Not sure about shouldder cuts first, though, I need a perpenticular piece to clamp to the stop block and fence. I figure your technique would work better if the shoulder cut would be done after the bevel.
But thank you very much!
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I made similar caps a few years ago and found that they were highly unstable. They stay moist on the underside and get baked bone dry by the sun on top, which caused them to cup severely and crack. If I were to do this again I'd at least use quarter sawn wood and would consider sheathing them in copper. Having seen what happens to wood caps I now understand why several companies sell metal ones.
John W.
Stained? Painted? Left natural?Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
It was pressure treated yellow pine left natural, but no finish would prevent the rapid moisture loss from the heat of the sun and the fact that, relative to the size of the cap, a huge amount of end grain was exposed to the air.
Two of the four beveled faces on the cap will be pure end grain and the sun will dry out the upper half of the blocks within an hour or two, while the shaded underside of the cap is supplied with moisture trapped in the area under the cap and moisture drawn out of the end grain of the post. Because if this, the difference between the the moisture content of the two surfaces will be huge. The five inch square caps I made curled up a half inch or more at their edges and basically self destructed over the course of one summer.
John W.
Nice post. Thanks. I do think several coats of paint would slow or eliminate the absorbtion of the end grain a tad. I do agree that end grain is like a bunch of open straws waiting to suck up moisture.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Here's my method for doing the low angle pyramids. It's based on using my 12" SCMS w/ a 100t blade and requires no sanding, so can't say it will work for you but here goes. Make a square box out of 1/4" plywood so the square blank just fits inside. Recess one end of the box about an 1" into a dado so it's square to the sides. The other end of the box can be flush. Make the box about 9" long. So for a 6" pyramid base you have a box 9" long with a 6x6 ID. Put a 3/4" hole in the recessed end and line the perimeter with self stick EDPM "P" shaped weather stripping. Punch a whole in the other end for your shop vac hose or a tube fitting if you have a vacuum source. Set your bevel or mitre angle on the chop saw, turn on the vac and put a blank in the end of the jig. Position the jig so that the bevel ends on the center line of the blank. Put a stop behind the jig and rotate the jig for each facet. It probably took almost as long to write this as to make the jig, but it's worth it, especially for multiples. With square blanks and a well fitting square jig you get a nice centered little pyramid point instead of a ridge or a off center point. The 100t FS Tools mitre saw blade leaves end grain like glass so there's no sanding.John O'Connell - JKO Handcrafted Woodworking
Life is tough. It's tougher if you're stupid - John Wayne
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