When making an L shaped kitchen worktop, it's necessary to a join at 90° or at 45° (using an inserted corner). It's also good to know the proper procedure, have the right jig, tools and accessories as well as enthusiasm before joining the worktops. This article will explain the proper procedure of joining at 90° in detail.
Step by step procedure:
Before we start working, it's best to settle which desk is the main one and which is the connecting one. The main one will have the inner part of the joint and the connecting one will serve as the outer part of the joint. I always begin by routing of the main worktop board, the inner part of the joint.
The IGM FK650 jig will help you achieve a precise connection along with a hand-held router, a 30 mm guide bush and a router bit of 12 mm. These parameters (guide bush and router bit) are important for the final form of the connection.
If you do not have a 30 mm guide bush on your router, you can buy the IGM FGB guide bush and connect it with your router using an IGM FRB universal clear router base. We can begin when everything's good and ready.
Making the inner part of a 90° joint
Step 1: Placing stops and an IGM jig onto the worktop
The IGM FK650 jig is supplied with three cylinder stops which help you to centre the jig onto the worktop properly. To position the jig properly, two stops have to be inserted into holes labelled C and one stop into an opening securing the height of the worktop. In our case, that's the opening number 60. Now we must place the jig over the worktop so that the C stops touch the front postformed edge and the stop in the 60 opening touches the cut off edge. The stop in 60 opening determines the length of routing and the depth of the following worktop. I work with a worktop 60 cm in depth.
Step 2: Routing the joint
Secure the positioned IGM jig to the worktop using clamps. I recommend using quality clamps that provide more pressure to secure proper hold to the worktop when routing. Before routing, make sure the revolutions of the tool cut into the postformed edge and cannot damage the front edge. Should the revolutions of the tool move out of the postformed edge, it would be necessary to turn the worktop upside down and clamp it the jig again from the front side of the postformed edge. Now we can start routing the inner joint. Set the speed of the router to 16 thousand rpm. And gradually remove the inner part of the joint. Remove the 28 mm worktop on three passes and the 38 mm on four. Guide the router using a bushing along the remote cutout edge in the jig. Remember that the router is only partially supported so you need to perform the cut on several passes. Excessive removal means an equal resistance from the tool and a possibility of an uneven cut.
Step 3: Routing holes for connectors
After removing the excess material, release the clamps and IGM jig, flip the worktop over and place the stops into the openings labelled D ( for connectors of 120 or 150 mm). If you're using 65 mm long connectors, use openings labelled D. Insert the third stop into the opening labelled B and place the jig over the worktop so that the D stops touch the routed of edge and the B stop is touching the rear edge. Secure the IGM jig using clamps. Use the same diameters of the tool and guide bush as in the previous steps. Set the depth of routing according to the height of the connectors. Now you can begin routing the two openings for connectors. When you're done, release the clamps and remove the jig. Now your inner part of the joint is complete.
Making the outer part of a 90° joint
Step 4: Placing stops and an IGM jig onto the worktop
Now grab the desk that will fit the completed one. Since we routed the first worktop from the upper part of the desk, now we will obviously cut from the lower part of the desk. Place the worktop face down, mount stops into B slots in order to fit the IGM jig on the worktop. These stops will ensure the right angle of the jig. Now we will place the IGM jig over the worktop so that the stops hold the postformed edge and the jig covers the whole worktop. Make sure to draw the length of the worktop before securing with clamps, that way, you don't have to shorten the worktop later. Count the length this way. Length of worktop (postformed edge of the main worktop) 300 cm + inner part of the joint 2,3 cm - 0,9 cm (shift of the cut edge towards the copied one), the final mark will then be 301,4 cm from the edge. The mark designates the edge of the jig cutout or the copied edge. Move the jig along the postformed edge up to the mark and clamp down.
Step 5: Routing the joint
Before routing, make sure the revolutions of the tool cut into the postformed edge and cannot damage the front postformed edge. Should the revolutions of the tool move out of the postformed edge, it would be necessary to flip the worktop and clamp it the jig again from the front side of the postformed edge. Now we can start routing the joint. Set the speed of the router to 16 thousand rpm. And gradually remove the outer part of the joint. Guide the router using a bushing along the remote cutout edge in the jig. Remember that the router is only partially supported so you need to perform the cut on several passes. Excessive removal means an equal resistance from the tool and a possibility of an uneven cut.
Step 6: Routing holes for connectors
After removing the excess material, release the clamps and IGM jig, flip the worktop over and place the stops into the openings labelled D ( for connectors of 120 or 150 mm). If you're using 65 mm long connectors, use openings labelled D. Insert the third stop into the opening labelled B and place the IGM jig over the worktop so that the D stops touch the routed of edge and the B stop is touching the rear edge (wall edge). Secure the IGM jig using clamps. Use the same diameters of the tool and guide bush as in the previous steps. Set the depth of routing according to the height of the connectors and begin routing the two holes. When you're done, release the clamps and remove the jig. Now your outer part of the joint is complete.
Finishing up and glueing of the joint at 90°
Step 7: Routing slots for Lamello biscuits
To simplify glueing and completion of the joint, rout three slots into the connecting edge, this will hold the worktop in place. Turn both worktops upside down, measure the pitch between the biscuits and draw it on both worktops. Fit your router with a slot cutter. Set the height so that the slot is approximately in the middle height of the board. The depth of the slot is secured by a bearing on the bit. After routing the slots, check the whether they are the right size.
Step 8: Finishing the edge after routing
The grain will have a tendency to face a certain way after routing, these can get in the way when glueing and setting the joint. Sand these away to secure a straight and finished surface. Make sure not to scratch the surface and edges of the worktop when sanding, this could influence the look of the completed joint. The joint is very susceptible to precision and even a slight dent can offset the final results.
Step 9: Setting the joint and glueing
To secure proper and tight hold, use a D4 water-resistant adhesive, we recommend Titebond III Ultimate, and sanitary silicone, ideally in the colour of the worktop. Apply the glue to the lower 2/3 of the joint and then apply silicone to the upper 1/3. The glue secures the joint while the silicone tightens and protects. Before the glueing itself, place the worktop on your cabinets and see if all fits. If everything's in order, apply glue and silicone and immediately clamp the joint using connectors. After pulling the worktops together, carefully place them onto the cabinets and screw them in.
When the glue sets, you will have completed the joining of worktops at 90°. You can also use the IGM jig to join worktops at 45°, to round over a corner of a worktop, cut at 45° or to cut out holes for sinks or stoves. The IGM FK650 jig will simplify your work.