Cutting a Miter Gage Groove in Plastic Laminate

[Scott C. Williams]

To prevent plastic laminate from chipping when cutting a groove for a miter slot is it better to cut the groove with a dado set, a router, or cut the groove with a dado set in the base material prior to lamination then follow up using a router for the plastic surface? I don't have a high quality dado set therefore a bit hesitate with this method.

[Jim Kountz]

I use my dado head but its a good 'ern so it leaves a nice finish. The last method you mentioned will probably yield the best results as long as your flush trim bit doesnt bottom out in the groove.

[John Jendro]

I used a router with a 1/2" bit and a straight edge. Two passes to get the right width and depth, worked great. Seemed like it was going to be easier to tweak the size of the slot with a router.

[Dale Lesak]

They make a special bit to do the dado grooves. it's a regular trim bit with a short rub guide on the bottom. I Made mine by cutting a regular bit off on the end. just left about 1/4 rub to guide the bit. had to use a diamond cut off tool. as mine was sold carbide.

[Joe Scharle]

A spiral bit (3/8 or 1/2) and a jig is what you'll want sooner or later. Doesn't have to be self clamping like this, but along the same idea.

http://www.ncwoodworker.net/pp/data/194/Rabbet1.JPG

[Scott C. Williams]

Joe,
Assume you would route a groove in both the laminated plastic and base MDF base together at the same time.

[Danny Thompson]

I used a 3/4" straight router bit in a simplified cousin of Joe's dado jig. Laminate and MDF together in 1 pass. Worked beautifully.

[Joe Scharle]

Yes, works in one pass. I normally use downcut spirals for dados. Recenty tried a compression bit and it cuts a little faster and throws out more of the dust in the dado. I hook up my Fein to keep the dust level down. Clamp a piece of ply on the end of the jig and you've got stopped dados. That pic was taken to show another WWr the setup for cutting a top edge rabbet on an 8' piece of ply.

[pat warner]

Can be routed with solid carbide (http://patwarner.com/images/404_b.jpg), not a lot of technique sensitivity here.
Saw blades are more than acceptable too.

[Cliff Rohrabacher]

For years all any one ever used to trim laminate were straight bits in routers.

[Mike Wilkins]

Use a utility knife to score a line where the miter groove will be located. I have used this method before on laminate and melamine. If you are going to use a dado blade to make this cut, try using masking tape along the cut line, and use a steady feed rate. It may not eliminate all chip-out, but it will greatly minimize any.

[Howard Acheson]

If this is for a router table, let me suggest that a miter gauge slot is not necessary. And, it can actually weaken the table allowing it to get out of flat.

The only practical use for a miter gauge slot is to mount a featherboard. However, featherboards can be just as easily mounted with a clamp.

What router operation would you do where a miter gauge would be used?

You can always put a miter slot in later. Try your table without on and see if you ever need it.