Question about cutting half lap joints

[Al Bacon]

Good Morning

I have to construct a face frame with half lap joints that will have to resist diagonal racking. I understand that these are the strongest joint for this type of construction. However I don't have a RAS and am not going to get one (no room). So I am wondering what everybody thinks about clamping the rails together as a group and milling the joint with a router. If I mill the center lap first I could fit a stile in it to register the group for the other cuts. Then do basically the same for the styles.

Will this work? Is it a truly nutty idea? If so what is a better way to do it?

Thanks

Al

[Prashun Patel]

You can certainly mill them with a router. You can do it with a hand-held router and an edge guide, or you can do it on the router table with a coping sled.

If you use the handheld option, make sure that you clamp backer boards on the 'leaving' side of the cut, or you will blow out the sides on your beautiful frames.

[Mike Ontko]

Al, do you have a tablesaw and dado blade? You can use this combination with a miter gauge, and check the length of the half lap using a stop block set up on your rip fence. Check out this WJ article on Cutting Lap Joints With A Table Saw (http://www.woodworkersjournal.com/cutting-lap-joints-with-a-table-saw/).

[glenn bradley]

I am a big router and router table fan. For laps and bridles I turn to the tablesaw. If you don't have a good quality dado stack, you can make a jig like this in no time to assure consistency:

314510314509314512

The internal height is 1/16" less than the stock thickness to allow a single clamp operation.

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These are just some hard maple web frames but, the same technique applies. You'll notice the jig is slightly larger than the cut. This is because the jig is used with a template guide. The first pic shows the stop that is in one end of the jig to assure position. Your router's depth stop(s) assure a good match.

[Mike Cutler]

Al

Nothing at all wrong with doing half laps with a router. The jig Glenn detailed is very nice.

Here is an example of half laps in a Macassar Ebony frame I did a few years back, with router templates and a router. A lot of hand finish work too, but the router was the prinipal tool of destruction. ;)

http://www.sawmillcreek.org/showthread.php?60965-Greene-amp-Greene-Stained-Glass-Window&highlight=

[Lee Schierer]

I cut half lap joints all the time. I use my tenoning jig on my table saw. I set a stop to get the face cut in the right location, make all the face cuts, then set the tenoning jig to cut off the area that will lap. I use a ripping blade to make this cut. You can adjust the tenon jig to get perfect match ups of the rails and stiles.

[pat warner]

Done on a special router table with a sled.
Cut at 14° (http://patwarner.com/images/dovetailed-lap.jpg) so there is a little extra measure of interlock.
Moreover, very easy to assemble.
Would not rout >1 at a time.

[Curt Harms]

You can certainly mill them with a router. You can do it with a hand-held router and an edge guide, or you can do it on the router table with a coping sled.

If you use the handheld option, make sure that you clamp backer boards on the 'leaving' side of the cut, or you will blow out the sides on your beautiful frames.

I might make each side cut of a half lap joint on the table saw. This would go quite a ways to eliminate tear-out on router bit exit. If necessary make a narrow scoring cut with the grain where the bit will exit the cut. Like Lee I often use a table saw tennoning jig when the half laps on on the end of a piece. That doesn't work well for half laps in the center of a piece though. A dado blade will certainly work but I find a router cut half lap is smoother and should present a smoother gluing surface than a one cut with a dado blade.

[ian maybury]

:) Hi Pat. Impressed at the clinical accuracy and clean cuts you always seem to manage….