# Need help with cutting large lap joints



## jnbrown (Apr 14, 2013)

I am cutting some large lap joints in Cedar 2x6.
I am going to remove most of the wood with vertical cuts on a saw and then chisel.
I don't think I have good enough chisel skills to get the bottom flat and clean so I plan to use a router to finish it off. I have a really old Sears router 315.17492 that only accepts 1/4" shank bits. What would be the best bit to get a flat clean bottom cut?
I am also looking at getting the Infinity Tools Universal 7" acrylic base because the one that came with the router is anything but flat and the 7" diameter will help span the large joints.

Thanks!


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## DaninVan (Jan 1, 2012)

Hey, Joel; somebody will be along shortly to explain the router ski concept, but since I got here first ...heh...I'll just clarify what you're doing, and make a suggestion.
Are you talking about a full dimension 2x 6 ie rough cedar, or S4S (1 1/2" x 5 1/2")?
If rough my usual ploy is to use my builder's saw and, starting at the end of the plank, cutting across it, make successsive closely spaced cuts of the exact depth I want. Then after cutting out maybe an inch or so, I run the saw along the length of the cut perpendicular to the direction of the blade...basically using the bottom of the blade like a router. If you're careful you'll get a pretty decent rabbeted bottom; just carry on along the full width of the lap.
This technique's limitation is what you want it for. If you were building a fence or pergola, it's perfect. If you're building a dining room table; maybe not so much.


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## jnbrown (Apr 14, 2013)

DaninVan said:


> Hey, Joel; somebody will be along shortly to explain the router ski concept, but since I got here first ...heh...I'll just clarify what you're doing, and make a suggestion.
> Are you talking about a full dimension 2x 6 ie rough cedar, or S4S (1 1/2" x 5 1/2")?
> If rough my usual ploy is to use my builder's saw and, starting at the end of the plank, cutting across it, make successsive closely spaced cuts of the exact depth I want. Then after cutting out maybe an inch or so, I run the saw along the length of the cut perpendicular to the direction of the blade...basically using the bottom of the blade like a router. If you're careful you'll get a pretty decent rabbeted bottom; just carry on along the full width of the lap.
> This technique's limitation is what you want it for. If you were building a fence or pergola, it's perfect. If you're building a dining room table; maybe not so much.


Yes that is what I am doing. It is for some gates on the sides of my house. The cedar is smooth not rough. I don't have a builders saw and even if I did not sure I would trust myself with it to do that manuver. I am using a sliding miter saw to make sussessive cuts using the depth stop. It is pretty fast and easy to remove the material between the cuts with a chisel. I might just be able to hit it with a sander after the chisel to get it flat and smooth. Just thought the router might be more percise.


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## roofner (Aug 1, 2010)

This is where much maligned RAS comes in with a dado blade and gauge blocks. You can set the depth of cut up with gauge blocks and scrape stock being used to make the joining pieces. You then can use the fence on the Ras to align with your pencil mark for the end of the half lap the hard part of the cut. Then just move the piece to make successive cut to finish half lap.


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## Cherryville Chuck (Sep 28, 2010)

The router is more precise. The saw method produces a moderately smooth surface but the router will produce close to dead flat. Also, using the saw is fairly slow compared to the router, especially if you have a few joints although scoring cuts every 3/4 inch will speed things up as it makes it easy for the router to get rid of the waste. I would use at most a 3/4" bit for this because you are limited to 1/4" shank. The trick with the router is to start at one side and finish at the other and prevent the router from tipping while you are eating away the waste. It helps to have a larger base or an offset base like Pat Warner makes ROUTER WOODWORKING scroll down and check the right side of the page.


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## jnbrown (Apr 14, 2013)

Cherryville Chuck said:


> The router is more precise. The saw method produces a moderately smooth surface but the router will produce close to dead flat. Also, using the saw is fairly slow compared to the router, especially if you have a few joints although scoring cuts every 3/4 inch will speed things up as it makes it easy for the router to get rid of the waste. I would use at most a 3/4" bit for this because you are limited to 1/4" shank. The trick with the router is to start at one side and finish at the other and prevent the router from tipping while you are eating away the waste. It helps to have a larger base or an offset base like Pat Warner makes ROUTER WOODWORKING scroll down and check the right side of the page.


Turns out Pat Warner lives not far from me. I will give him a call.

Spoke with Pat, he told me my Sears router isn't up to the job and I should consider a PC 690.
Amazon sells then for $125. Didn't want to buy a new router but I think he is right.
He will make me a wood base for around $50 and Acrylic for $75.


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## DaninVan (Jan 1, 2012)

Aside from the current project, you really really want a builder's saw! 
Walking around with an 8 1/4" Dewalt, and a baseball cap, will get you brownie points with the missus, especially if you actually make something...


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## jnbrown (Apr 14, 2013)

Scored a PC 690 on Craig's List for $65. Made in USA!
Came with an extra base attached to a large piece of MDF that might work for my project.


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## harrysin (Jan 15, 2007)

A 1/4" router is certainly not the right tool. Using a 1/2" router with template guide and a simple jig is one of the methods that I use.


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