The primary reason for this was to keep the new dog in after a few breath holding moments with him running into the road.
I've yet to treat the gates with wood preserve yet (waiting on a sunny day) but after i do, there will be chicken mesh put across the bottom so he cant get through the gap. Might keep the cats out too.
To start I measured the gate width and height of the granite posts already in place. made allowances for the hinges (not enough really as in the end they only just fit in with a bit of modification)
Step 1: The Frame
The upright posts, made from the bottom rails from a pallet, were cut to the same height as the granite ones meaning when hung they would protrude just above. The angled top is for water run off (modified later for a better look)
The top rail was cut and a Tenon joint was cut each end. Use a circular saw set to the right depth make lots of thin cuts along the the wood to be taken away. This makes chiseling much easier.
Break off the cut sections and clean up using a chisel. Its better to use a wider chisel than pictured as it is easier to get a flatter cut. Make sure the chisel is VERY Sharp. This is much safer and more accurate than a blunt one.
Mark out and cut where you want the mortise joint to be. Measuring the tenon and cutting to this size will give you a nice tight fit. I Started cutting these using a tank cutter on a pillar drill but switched to a flat blade cutter when i found them (sooooooo much easier)(last picture)
Use a sharp chisel to clean and square up the mortise joints.
For the two bottom rails i used the flat slats from the pallet. Marked where i wanted them and cut the mortise to fit the size of the slat. Test fit all the parts and get it square, put some holding screws in place. This will keep it square as long as you don't try to move it too much.
(EDIT: as pointed out in a comment below, the way i built the angled peice is wrong. The brace should go from the bottom of the hinged side to the top of the latch side. Although i have changes the wording the pictures remain wrong. Please bear this in mind when following the steps below.)
The diagonal brace, made from a pallet slat, will fit from the bottom of the hinged side to the top of the other side. this is to stop the gate sagging under its own weight over time. Measure and cut the Slat and make the angles cuts at each end. Mark the top bar where it is crossed by the diagonal.
Cut the angle on the top bar (setting the saw to the depth of the pallet slat) Remove the excess wood with a chisel to give you a nice slot for the brace. Shown below the brace fits in flush. (i replaced this piece after the screw split the end. Avoided later by drilling a pilot hole)
Assemble the Gate ensuring it is square. drill and bolt. I used dome headed stainless steel bolts making sure the domes were on the outside) I added extra screws in mine for strength but screwed them in about 1cm so when the wood swells these will get hidden
Two gates complete. In the last picture you can see i chopped the top on the angles just for appearance sake really.
Fixed using a hook and eye set up. Available at most DIY stores or farm supply shops.
Anchor bolts keep the hook firmly in place.
The eye part is adjustable and although you cant see it in the picture it does has nuts on each side. (one is countersunk due to my earlier mistake with width measurement.)
As i say the only things left to do are treat the wood, Apply the mesh and maybe put in some gate latches to hold them back when open. May even go posh and have electric gates one day. But not right now.