Walnut, 1/2", Box Joints, Router, Chip-Out

[Bill Wiggins]

Hello everyone,

I'm building a toolbox loosely based on the Gerstner design out of 1/2" walnut.

http://www.gerstnerusa.com/toolchests/w41d-b.htm

While attempting 1/2" box joints on my router with some test walnut pieces, it chips out terribly. It destroys the wood. I've tried different speeds, bought a new PC router bit, but it still destroys the piece. I'm using a "fence" similar to the concept used on "The Router Workshop" videos.

http://www.routerworkshop.com/boxjoints.html

Any ideas would be heartily welcome. I'm trying to avoid buying Dado blades for my table saw, but at this point it's looking like a better option than the router.

--------------------
Bill Smith

[Chris Mann]

Are you backing up the work with a sacrificial fence? If you're having problems with it blowing out the back that should solve it.

[Bill Wiggins]

It's happening on both sides. Yes, I tried some wood in front and in back. At first I used Walnut, then poplar. Had the same problem. Then I tried just routing about 1/3 of the final depth. After three passess for each pin, it seems to be OK. Unless someone has another idea, I'll have to adjust the router depth three times for each cut.

[Kris Koenig]

Are you using a spiral bit or a straight bit? I had the same problem trying to cut box joints using a straight bit. Nobody local had spiral bits, and I didn't have time to order one.

Kris

[Bill Wiggins]

Kris,

I am using a straight bit. Perhaps I'll try to find a spiral bit somewhere nearby. Did your problem get resolved after trying a spiral bit?

[Corey Hallagan]

The Spiral up cut bit will make all the difference. The spiral is sharper plus the top of the router bit cuts all the way across the top of the bit, that's where the rip will start from. Larger bits like 3/8 and 1/2 can get expensive but they are worth the investment.

Corey

[Kris Koenig]

Kris,

I am using a straight bit. Perhaps I'll try to find a spiral bit somewhere nearby. Did your problem get resolved after trying a spiral bit?

Actually, I just changed the joinery style. I didn't have time to order a bit, but I have no doubt that the spiral bit would have solved the problem. Just like the new spiral jointer heads, it would slice through the short grain instead of chopping. The chopping is what was blowing chunks out of the fingers.

I plan on ordering some spiral bits when I rebuild my shop after Hurricane Katrina came to visit. I have already started getting some tools, now I just have to convert the garage.

Kris

[Kris Koenig]

I also noticed that I had a lot more trouble with the long grain fingers than the end grain ones. When you cut the long grain, you automatically make a lot of short grain with the router bit hitting it on the end. The straight bit would just knock whole fingers off. Theoretically, the spiral bit would slice the wood, causing less impact. I don't remember having too much trouble when cutting fingers in the end grain of the board.

Kris

[pat warner]

Sandwich the work between 2 hardwood pieces of scrap. Now if the work is still screwed up I might be of some help. Will you check that?

Routers

[Ralph Barhorst]

I always use a spiral bit for this type of work and it works fine.

I use a 1/2" end mill. They are cheaper and work just as well as a router bit. Get a 2 flute bit if you can.

[Guy Germaine]

This may be a dumb question, but some times the easiest place to hide something is in plain sight!

Are you cutting the joints in the proper grain direction? What I mean is the long grain of the piece should be perpendicular to your router table. If not, you're cutting across the grain and even if you get the fingers cut, they'll be very weak.

Like the others have said, make sure you use a scrap backer piece.

[Bill Wiggins]

Thank you everyone, for your advice. I will probably by one of the spiral bits when I can justify some new purchases. I sandwiched the two pieces tightly between two 3/4" birch plywood pieces and built a tall fence for the router to help feed it into the router. I had no chipout.

I used a 1/2" wide x 3/8" high "fence" to guide the piece. I have to practice a bit more with the appropriate distance setting, since it came out just a bit too loose.

I had to delay the toolbox, since a variety of errors chewed up too much of the material. Instead, I'm making some boxes for a friend to keep the dogs' toys.

Thanks again for everyone's help!