Replies

1. 
   ring | Aug 25, 2006 08:46am | #1

   Not sure I understand the question...You need to make an "L"-shaped countertop?  If so -

   If its exactly 90° and you have a good tablesaw it's no problem.  If your TS isn't up to it, or if you need to tweak the angle a bit, try this-

   Cut both pieces at approximately the right angle with anything, even a jigsaw.  Mock up the desired layout and clamp them in place, leaving a 1/4" gap between the pieces.  Use a guided router and straight 3/8" bit to run through the joint and make the fit perfect.

   Cut the other ends off to size after you're satisfied that the joint is right.

   DR 

1. 
   pebbles | Aug 25, 2006 08:32pm | #4

   Ring, thanx for your comments. The laminate will be applied to the substrate in place. Sounds like it's not as big a deal as I had imagined. Thanx again, Pebbles.

2. 
   mike4244 | Aug 25, 2006 06:18pm | #2

   If the laminate is already attached to the substrate, try this.Turn the top upside down,mark the miter on the bottom and backsplash if there is one. Use proper length screws to fasten a straightedge . Put a sharp combination blade with 40 teeth in saw.Where the saw will exit the cut, handsaw with a hacksaw to prevent tearout.

   Then cut thru the top. The particle board or whatever can be trimmed back very slightly with a router. Use a top bearing bit, use a slightly undersized bearing. The result will be two edges of laminate with the substrate undercut slightly. Screw and glue a piece of plywood to the underside of the top,just on one side for now. When you bore the holes for screws,countersing both sides of the plywood. Any trash from the particle board holes will fall into the countersink instead of getting trapped inbetween the particle board and the cabinet base.

   If the laminate is not glued to the substrate, do exactly like the first post said. Cut the miter , use a router and a dovetail bit to cut thru both pieces at once. The dovetail bit gives you a slight bevel, easier to get a perfect seam.

   mike

1. 
   pebbles | Aug 25, 2006 08:23pm | #3

   Mike4244, thanx for your comments they are greatly appreciated, Pebbles.

3. 
   cowtown | Nov 02, 2006 08:25am | #5

   The counter top has two surfaces of significance, the top and the front edge.

   If you want to to mitre the top edge, it gets a tad tricky.....moreso if it's a post-form countertop.

   First off, is the corner actually 90 degress.....????

   you can cut post form counter top with a sharp ine tooth handsaw, but do expect it to dull, and it is indeed a case of measure three or four times before you cut.

   Measuring an accurate 45degree angle on a post-form countertop surface is an excercise in geometry.

   You finaly mark your line and having dubble checked it, at 45 (or other angle if the corner ain't quite 90) and saw proud of the mark on one side.....by just a 1/16 inch, and then use a belt sander to sand up to your mark. Use a good flat piece of ply against yer finished edge to assess that that edge is good and straight.

   Cut the other side same way, put the two pieces together, and see where the high spots are, sand judiciously to make the two ends butt together neatly.

   This could take a lot of trial and error. There is a reason that the countertop mfgrs charge what they do for cutting mitres. And if I had my choice, I'd let them do it. ....but you did ask..

   Any openings will just be a place for water to seep in and swell the particle board and turn yer work to crap real quick, so the joint has to be real good. Sometimes a real sharp block plane is effective for trimming down little areas.

   When joining up the two pieces, don't forget the biscuits to align the pieces, nor the counter top jointers, which you will have to router in from the bottom. And don't forget to glue the joint, and apply a tiny bead of silicone from the top when yer glue is dry. Gotta keep the water out of it.

   I've had to do this a couple of times, and it's not a task I would undertake willingly.I'd rather have the mitres cut by the postform countertop fabricator than assume the risk of a mistake or a mis-step.
   And I've had to pay for a mis-step or two along the way, so they can happen.

   Most of the L-shaped countertops I encounter are "laid up" countertops and are easily accommodated with 5x12 laminate sheets. No joints. And after replacing a lot of countertops overlaid on particle board, I use fir ply substrate. Backsplash is typically tile.

   For mitres on edging, I use a shooting block, which is nothing more than a jointed square 4x4 with one end cut at a 45 and the other end at 22.5, and a narrow slot cut in it lengthwise to hold the 1 3/4" edging strips and then use a block plane to "shoot" the edges to the appropriate angle.

   Hope this helps.

   Eric