I have some clear cedar porch posts, and at the bottom end, I wish to do a deep mortise, for socketing-in the steel blade of a fabricated post base and anchor.
Posts are 4×4 nominal, actual 3-1/2 x 3-1/2, and the desired mortise is 5/16 to 3/8 wide, maybe 2-1/4 wide, and 4 inches deep.
What is your suggestion for doing these? I’ve 16 to do.
Replies
You could rip them in half, dado the mortise and glue the two halfs back up. That is if you can stand to lose a curfs width. You'll hardly notice a glueline with a proper rip blade.
Andy
Why not post this question over at Breaktime? That is the construction/homebuilding chat site and there are lots of guys there who have the kind of experience you're asking about.
If you have a good eye you could use a bit and brace to make the 4" deep holes and clean the mortise up with a good chisel. The long length of the bit and handle make it easier to judge 90 degrees. Or you could flip the plate on the drill press sideways and with 2 fences and clamps drill the mortise that way.If the posts are not too long you might be able to raise the drill press high enough. James
The 4" depth seems to be the main stumbling block. Can't really use a TS unless you've got a 12" one. It also sort of rules out using a router and even finding long enough forstner bits would probably be difficult. If the mortises are just for clearance for the hardware and the exactness isn't a big issue, you could probably use a spade bit through some jury rigged jig that would slip over the end of the posts to provide a drilling guide for location and to help guide for squareness.
The only other thing I can think of - if you have a bandsaw - is a variation of AEsarte's suggestion. Make two 4" kerfs completely through the 4x4 and pop the middle section out by drilling through at the top of the cut. Then clean up with chisels (easy on cedar) and glue cedar spacers back into the slot at the outside edges to box in the hole.
Waddaya mean it wont fit through the door?
The peices are 3-1/2" and could fit in a 10" t.s. And you can rip up to 7" if you flip the piece.
Yeah, but I was suggesting an alternative to ripping the entire post and regluing. I was suggesting just cutting out the 4" slot in the middle then gluing spacers back into to the outer edges of the slot. Wouldn't work on a 10" TS.Waddaya mean it wont fit through the door?
I had to set a dozen stair newels on balconies over post and beam construction. I have a radial head drill press. I tiped it on it's side and used a forstner bit to drill a 4" deep by 2" hole. You could use pipe or solid rod instead of the bracket. A hole is much easier even if you had to make up a jig to use a hand drill. There would probably be less chance of the post splitting from a side shock with a round mortise.
A chain mortiser would make quick work of this if you could find a local cabinet shop that has one.
Gene,
I wonder why the base needs such a long tenon.. My inclination would be to cut the stubs off at about 1-1/2", and cut a correspondingly shallow mortise to fit. Once the posts are in place, where are the bases gonna go?
Regards,
Ray
Drill them and clean 'em up with a chisel. It's cedar, so it isn't a hard wood, and it's for sticking on a post anchor, not for a glue joint. The usual rules of precision joinery for hardwood M/T joints don't apply. You might consider making a simple jig to clamp on to the post with drill guide holes set in the correct place (a 1" thick piece of pre-drilled maple glued or screwed to a piece of plywood with two edge registers, and use 1 3/8" auger bit and you be stylin').
Gene I have a Powermatic chain mortiser that would do that if the length of the 4 X 4 is not too long. If it is long maybe you should see if you can find someone who builds post and beam houses. I have seen portable chain mortisers in the catalogs that clamp onto the beams from the sides, so length would not be a problem.
Did a similar operation by mounting an electric chainsaw on a plank with some spacers under the bar and screwed some guide blocks to register the posts and slid the posts into the saw chain. A poor mans chain mortiser and it worked well. Slipped a shim under the posts to widen the kerf on the second pass.
I like your thinking.
Had considered an end registered block with drill bushings,laid out so that flipping registers would halve the first series of drillings.Drill bushings prevent the drill from walking.Figured clearance was acceptable,needn't have the typical shake-free fit of M&T.
My cobbled chain mortiser was quick to set up and needed very little special hardware. A couple of holes drilled in the bar and a wooden spacer block that was simply ripped to size mounted on a 2 x 10 with a couple of cleats to hold and guide the wooden posts. Easy to quickly adjust as well and was safe enough as my hands were well out of range to feed the post. A small electric chainsaw was perfect.
So, just to see how things felt, I put a nice long 5/16" bradpoint bit in my cordless drill/driver, clamped a scrap of 2x4 in the vise, endgrain looking up, and eyeballed a series of deep holes into the end. I didn't even mark for my cut, just tried to keep in a line. One hole out of the nine or ten wandered a little bit from a line.
Used a big 1-1/2 chisel down the sides, a mortising chisel on the ends to square corners, and a shop vac to suck out the waste. In less than 5 minutes I had a reasonably good mortise 3" deep.
So, I think when I get to production time, I'll have a hardwood guide block made up with registration ears, to guide my drill.
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