Saturday, May 12, 2018


Gradients...  As I walked out to my barn this rainy morning, this rock wall caught my eye.  This is the rock facade on the bottom of my barn's exterior walls.  We're having a very gentle rain, and there's basically no wind.  Above this wall, the steel roof extends out about 18", and there's no gutter.  That means the drips from my roof fall down in a straight line parallel to the wall, but about 18" away from it.  The roof at that point is 12' high, so those drops are falling pretty fast when they hit the ground.  Every time it rains, a muddy puddle forms along that drip line, and when the drops hit, they splash.

If you look closely at the rock wall, you'll see two separate gradients.  The easiest one to see is at the top, between the wet rock and the dry rock - there's a slow transition between thoroughly wet and completely dry.  That's the natural distribution of the splashed drops – the higher you go, the less likely that any drop will reach there, so the less wet it is.  That gradient looks like a linear density change to my eyeball, but I could easily be wrong about that.

The second gradient is hard to see in the photo (though it wasn't hard at all standing next to the wall).  It's a dirt gradient. :)  Near the bottom of the wall, there's quite a bit of mud splashed up on the wall, darkening the rock more than just plain water could.  As you go higher on the wall, there's less and less mud.  Again, it looks like a linear density change to me.  I'm making an educated guess that because a splashed droplet containing mud has a higher specific gravity than plain water, it weighs more and therefore can't fly as high.

I'm sure this dual gradient has been here ever since my barn was built, but somehow I never noticed it before.  I'm planning to put gutters up there this year, so after this year I don't think I'll see it again...

The grill cabinet is started!

The grill cabinet is started!  I was able to put four solid hours into this yesterday, and I got a lot further in that time than I expected to.  The first photo below shows the four pieces of a side frame, after cutting and drilling.  The poplar is very fine-grained, saws beautifully with no splintering, and drills easily and smoothly.  It's very nice to work with.  The second photo shows a horizontal piece (with the holes) and a vertical piece clamped together and ready to be screwed together. 

My friend Mike B. warned me that I had to be careful that the alignment didn't drift apart as I screwed in the special screws, but with the clamp as shown I had no problems at all.  He also warned me that the square driver tended to pop out of the screws and into his hand; again, I've had no such problem. 

The third photo shows all four main members screwed together.  To my surprise, the squareness of the result was perfect – no tweaking required.  The fourth photo shows the same side frame with four diagonal pieces put in for strength.  That's a completed side. 

I then built a second, identical side and a slightly wider frame for the back, using the same general design.  In the fifth photo one side is clamped to the back, ready to be screwed in.  This was my first attempt at a 90° joint using the pocket screws, and it worked just as well as the other joints.  Finally, the last photo shows both sides connected to the back.  That's a nice strong frame, and the building of it was easy and fast.  This cabinet isn't going to be as much work as I thought it would be! 

I have three units to build, all similar but different in the details.  Today I'll finish the burner unit (that's the one I've started) and start on the other two.  I suspect I'll be all done with the poplar cabinet framing by Tuesday at the latest (tomorrow is ... yuk! ... bookkeeping day).  Then it will be time for the plywood tops and bottoms...