Saturday, April 27, 2013

Lo-Cust Raised Beds? Part II

Perhaps the most enjoyable aspect about this project is the opportunity it presents to not sweat the details so much as I tend to do when making a piece of furniture or the like. It's a chance to just make something without losing sleep over it and to be accepting of imperfections. Very freeing really.

I had also forgotten what it is like to work with relatively green material - a dull chisel suddenly becomes a slicing weapon of unsurpassed durability. One can imagine weeks going by between sharpenings. After years of working with extremely hard woods like Jatoba, Wenge, bubinga and rosewood, and recent months of work with Burmese teak, which is a highly abrasive, edge-devouring monster, it is a relief to slice and dice material without having to think too much about edge retention, reassessment of bevel angle, and all that - whatever I happen to have near to hand in the chisel roll seems to work just fine, coming or going. I feel like I could almost pare with the other end of the tool fer gawd's sake. Okay, I exaggerate.

Today's blog entry, and the photos to follow, represent the work completed today between 9 and 5. After yesterday's joint and plane session, I lined up the boards and laid out the joinery. For this application, I am going with double-wedged, multiple mortise and tenon. In this case, I am doing the joints bare (i.e., without shoulders) as this is the simplest form and all that is really merited in this case as far as I'm concerned.

There are 2 end pieces, and 2 middle cross pieces which keep the 2 long sides together. Here's a view of the completed layout of the mortises on the long pieces:


Then it was on to hollow chisel mortiser land for a good long stretch:


The middle cross pieces attach with 2 tenons, and are a little less than half as tall as the side pieces:


A while later, the mortising was complete:


The boards are 30mm thick, and I figured a flare of 3mm was about right on each side, 3/10 giving a 5.71˚ angle of flare. I used my chopsaw to prepare a  paring guide block and tackled the next part with, er, flair?:


Two mortises have their flaring complete - another 22 to go:


Then I cut tenons on the two middle cross pieces and kerfed them for wedges - no real need for the pencil lines, but I did them on these anyway:


The end pieces also were tenoned - four tenons for these. Here they are after rough cut out:


A bit of paring and tweaking and the parts start to come together:


Down it goes, with some entertaining wood squeaks and groans:


Peekaboo!:


The middle cross pieces were likewise fitted up - you can see how the bare tenons reveal any imperfection of fit at the mortises:


Exit face:


Another view:


I gave the upper arrises of the long side and end pieces a quick chamfer with a plane, just to keep any potential splinters at bay for a while at least:


Then I took the end pieces and kerfed their seemingly endless tenons - skipping the pencil lines this time:


The upper two are kerfed:


Once the kerfing festival was over, I proceeded to assembly:



That was relatively uneventful, and the parts came together cleanly. The frame was then flipped back onto the sawhorses for wedging:


I found a piece of Jatoba which could be sliced up for wedges, made the 48 wedges plus a few spares on the chopsaw. The wedges I made at a total of 6˚ flare. Then, with the frame clamped up, I drove them in one by one:


I decided to be non-paranoid and spared the glue altogether - usually I would put glue on the wedges. we'll see how it does over time. Outdoors is going to be a harsh environment and we'll see how shrinkage and deterioration affects these joints over the next few years.

The first tenon is nearly all wedged up:


Then a row:


Once the wedges were in it was pretty much done. It came out okay, but not a piece for the fine furnishings show to be sure.

One last step was to put some latex paint on the exposed bits of end grain, which should help mitigate, I hope,  a certain amount of weather-induced degrade over time:


I'll probably trim the wedged tenons flush to the surface tomorrow. The wood will likely shrink a bit and make them proud later on. Tomorrow morning I'll pop down to the shop, finish that bit off, and drag the sucker home. My wife has been away for a few days so I'm thinking she might like the surprise tomorrow.

I'll see how the first one looks in the garden before making the next one - might want to narrow it down a bit, ya never know. This first one took about 10 hours altogether, however the long side pieces for #2 are already mortised, so it should be a bit quicker to build.

All for now, thanks for visiting.

4 comments:

  1. Dale,

    most kind. It's really a quick and dirty sorta project - and one which will even be dirty in another day or two!

    ~C

    ReplyDelete
  2. I admire you for going to the lengths that you did Chris.

    I built a raised planter for the missus and just used pt 4x4's with rebar. The wall itself is fine but the seats I put on top are pants. I used some cabot exterior stain and it's virtually disappeared and the boards are cupped.

    Lesson learned( was going to use cedar) so I'm going to plane the tops down now that they've hopefully settled and try a bit of shou-sugi-ban and see what happens.

    ps is the online group still going? I'm thinking about joining up.

    ReplyDelete
  3. Pat,

    your comment is appreciated. Yes, the online groups are going strong and just drop me a line if your thinking becomes more decided as to getting involved.

    ~C

    ReplyDelete
  4. No direct link with above but you might like this video :
    "La tradition du tracé dans la charpente française"
    http://www.youtube.com/watch?feature=player_embedded&v=8TmYdAUX6pA

    Very intersting French site:
    http://bois-de-brin.fr/

    Sylvain

    ReplyDelete

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