Laminate Seaming

A quick lesson on achieving a tight, clean laminate seam. June 10, 2006

I am laminating a site built countertop and need to seam laminate for a large L shaped top. How do I get a tight seam on the job site?

Forum Responses
(Laminate and Solid Surfacing Forum)
From contributor T:
Overlap the two pieces slightly. With a router running down a straight edge cut through both pieces at the same time. Make sure the lam doesn’t shift, so clamp or tape the lam to a sheet of pb or ply.

From contributor C:
I use 2 4" x 1/4" x 40" straight edges and sandwich one piece laminate in between. Use a sharp flush trim bit to run along the bottom straight edge. Repeat with the other side. File the bottom edge or the laminate back a little to help the fit. Keep glue off the edge of the seamed edge to help keep the joint tight.

I glue the whole thing up at once, lay one piece on dowels and align, then stick. Lay the next piece down and stick the seam first. Roll the seam to make sure it doesn't move, them leave one 1/4" dowel 16" back from the seam and continue sticking the rest of the sheet. This leaves a bubble in the sheet. Look at your seam and see that it is straight but still has a black line. Remove the dowel and roll the bubble out toward the seam, it will all but disappear. It is possible to cause the seam to lift, so make sure you roll the seam before the bubble, and make sure you are 16" back, or the bubble is too big.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor P:

I agree with contributors T and C with slight variation. Rough size your laminate pieces then lay them on a piece of MDF 20-30 inches wide. Now clamp a straight edge on each side of seam using a router, centered on the seam, to establish the spacing. Use a dovetail bit set about 1/16th deeper than the laminate and make a cut along the seam between the straight edges. Use a sharp 1" chisel laid flat on the laminate to shave the surface burr and a sanding block to clean the back of the laminate.

Apply the laminate as explained above with the rolled out bubble. The dovetail bit gives the edge of the laminate a slight bevel which allows the face to touch before the back which when rolled out as explained gives an amazingly tight joint.