mickael wrote:

I need to do a few joints in work surfaces, a couple of them right angles.
Any advice on the way to do these joints would be greatly appreciated. I
understand the principal of the long screw bolts and assume that I router
out the grooves for these. My main concern is the cutting of the work
surface

a) can I use a circular saw?


Its not a very good finish, even with a straight new fine tioothed blade.


These days I cut over size and finsish with a fine pass from a router
set at pull depth. Packing tape over the cut surface allows lines to be
easily drawn and helps prevent surface chipping.



b) for a 600mm surface at right angles do I cut a straight line for , say,
580mm and then a 45 degree cut for the remainder?



From memory, its a bit less than 20mm. More like 10mm - just enouh to
get proper mating on teh curved front edge. Its not pssible to rout the
internal angle, so a very fine fretsaw and chisel is used to clean up
the angle.



c) in addition to the bolts pulling the surfaces together I have also seen
biscuit joins in some situations - how important is this?


The only important thing is to get teh two bits immoveably clamped
together and a watertight seal. I have often done no more than screw a
batten underneath. I tend to use car body filler to glue them together
as well -waterproof, and suits my usual dark grey finishes well. If the
units are well mounted, and won't move, and teh tops are screwed down to
them, the batten is enough to stop the halves wobbling apart. If you do
have the routing jigs for the more complex ways - well why not sue em. I
think teh biscuits are there to senure vertical alignment so there is no
ridge. In my case, the join is suaually over a cupboard or void, and the
batteen does the same.


Any minor imperfections can be filled, by the way, with coloured epoxy
filler.