Had a long day is all, on site for 7.30am, afternoon meetings - developers talking rubbish for hours on end - self-employed = freedom? Yeah, like having eyes put out with sharp sticks = partially unsighted.
Anyway, try this.
1 scribe both worktop backs into walls for good fit ensuring that both worktop back corners fit into the corner you are jointing. NB both worktops must have their back corners right into the angle of the two walls.
2 establish which worktop will be routered from underneath (router into the profile from left to right) this is the one you will router first (hereafter worktop A).
3 lay A over the top of the other worktop (B) in-situ, using an offcut of worktop to support the opposite end of A and therefore keep it level.
4 mark profile A with a Stanley blade where it meets profile B. To do this accurately, rest a set or adjustable square on the top of A with the ruler pointing downwards and flat against the front profile of A. Move it into the corner where the profiles meet, and when the front edge of the ruler comes against the profile of B, make your mark on the profile of A using the edge of the ruler as your guide. 10-15mm mark top to bottom in the centre of the profile is fine.
5 put A on your trestles upside down, loosely clamp your jig onto the worktop in a diagonal line from your profile mark to the back corner of the worktop.
6 fine position your jig until it is set 9mm behind the profile mark, and 9mm off the back corner. You can test how close you are to the mark by putting your router guide bush against the jig, plunging the cutter to your profile mark and rotating the cutter by hand (make sure its not plugged in please - don't wish to be sued) until one of the blades is against the profile . This will tell you whether you need to move the jig back/forwards to get the cutting blade right on the line. A tap on the jig with a hammer is as good as anything for fine adjustment.
7 when you have your jig set 9mm off front and back and you're happy, tighten your jig clamps and start routing, 2-3mm pass first and then without moving the jig, cut off the excess worktop with suitable saw. 4-5mm passes thereafter. 5-6 passes should get you through the worktop.
8 put A back on top of B and line up the profiles using square method described above, your routered joint in A should now meet profile of B with the back corner of A in the intersection of the walls. Run Stanley blade carefully along top of B right against joint in A making 10-15mm marks at a time - front middle and back.
9 pull B out and place on trestles right way up, set jig up 9mm back from Stanley marks, clamp tight and rout away.
10 put worktops together admiring how closely they match and mark them both underneath for your bolt keyholes.
11 invite mates neighbours family round to show them how skilled you are, and offer them your services for about £50 a joint.
You can make you're own mind up which method to use.
Very best of luck.
PS Not mass - CofE
Lapsed in any case. I stopped trying to live up to my name 30 years ago
