Dovetail Bit Size

[Edward Weingarden]

I'm getting ready to make some drawers with dovetail joints for the first time. The sides and back will 1/2" ply and the front 3/4" ply. I have a 1/2" diameter dovetail bit but it would seem that would be too large to use for 1/2" ply. Is my thinking correct? Do I need to use a 1/4" or 3/8" bit? Thanks.

[Ron Selzer]

what dovetail jig are you using and what is recommended in the manual?

[Edward Weingarden]

Ron:
I'm not using a jig but will do it on the router table.

[Yonak Hawkins]

Edward, since you're designing you own dovetails and not relying on a standard template, I would think the bit size is your own decision regarding how wide you want your dovetails.

[Matthew Curtis]

Good luck in not destroying your plywood. The dovetail bit may completely tear out the ply.

[Dan Hahr]

1/2 inch dovetail bit is fine for half-inch plywood. You were only using a portion of the bit approximately a quarter or 5/16 inch deep. You can increase or decrease the depth of the bit to make equally spaced dovetails fit properly. But since you were not using the full depth of the bit half inch is not too big.

Dan

[Edward Weingarden]

The issue at hand is, if I route the dove tail groove (female) on the drawer fronts with a 1/2" bit, and I use 1/2" ply for the sides and route the male component (taking off at least some small amount at the widest part of the male insert), won't the male component be too loose in the female groove (which has a full 1/2" at the floor of the groove)? Since I haven't done this before, perhaps I don't understand the process.

[Edward Weingarden]

Matthew:
Thank you for the alert. The drawers are for a cabinet in the shop, so I won't mind a little tear out. I'll do a test piece and see how it comes out. If there's significant tear out, I'll get some pine boards.

Dan:
Thanks for the explanation of how it works.

[Mark Hockenberg]

Edward - I agree with Dan. A 1/2" bit will work fine in 1/2" material. I just finished some shop storage drawers with half-blinds using all 1/2" baltic birch. With my jig the pins extend pretty deep into the fronts and backs (see photo), but came out OK. To avoid the tearout issue on the pin boards, make an initial shallow pass across the width.

408933

[Edward Weingarden]

Thanks for the photo Mark.

[Jon Nuckles]

The issue at hand is, if I route the dove tail groove (female) on the drawer fronts with a 1/2" bit, and I use 1/2" ply for the sides and route the male component (taking off at least some small amount at the widest part of the male insert), won't the male component be too loose in the female groove (which has a full 1/2" at the floor of the groove)? Since I haven't done this before, perhaps I don't understand the process.

Edward,
From your description, it sounds like you are using a sliding dovetail joint rather than the type of dovetails that others here are thinking of. If so, you are correct that a 1/2" dovetail bit is going to route a groove too wide to be filled by your 1/2" thick sides. Even if you could cut the male side of the joint so that you removed nothing from the sides at the end of the joint, which would be a very tough task, your 1/2" plywood is probably not a full 1/2" thick to start with. Use a smaller bit.
Jon

[Edward Weingarden]

Edward,
From your description, it sounds like you are using a sliding dovetail joint rather than the type of dovetails that others here are thinking of. If so, you are correct that a 1/2" dovetail bit is going to route a groove too wide to be filled by your 1/2" thick sides. Even if you could cut the male side of the joint so that you removed nothing from the sides at the end of the joint, which would be a very tough task, your 1/2" plywood is probably not a full 1/2" thick to start with. Use a smaller bit.
Jon

Jon:
You are correct; it is a sliding dove tail I plan on doing. I should have clarified that in my original post.

[Dave Richards]

Since you've identified that you are using sliding dovetails, as Jon points out, your half inch bit will be too large. A smaller bit is called for here. In addition, I would suggest that you hog out most of the waste in the sockets on the drawer fronts with a spiral upcut bit. This will make cutting with the dovetail bit easier and safer.

[Robert Engel]

Edward,

First, you need some king of jig to do DT's with a router safely.

I recommend doing through DT's. Make the entire drawer out of 1/2" material, then apply a front.

Either way is fine but I suggest doing the tails first since your dt router bit will establish the pin angles. Use a backer board on both sides to reduce tear out.

I usually make the drawer bottom grooves first, although you can do it either way. The reason I do this is so I cut the back down before doing the rear side DT cuts - just eliminates an error.

Just a note: I've really abandoned DT's in plywood. For utility drawers I use plywood but I do a rabbet on the sideds and 1/8" dowel pins or screws and plugs.

I think you're going to find for just a few drawers, the set up time and aggravation factors are not going to be worth it.

[Dave Richards]

Edward,

First, you need some king of jig to do DT's with a router safely.

I recommend doing through DT's. Make the entire drawer out of 1/2" material, then apply a front.

Either way is fine but I suggest doing the tails first since your dt router bit will establish the pin angles. Use a backer board on both sides to reduce tear out.

I usually make the drawer bottom grooves first, although you can do it either way. The reason I do this is so I cut the back down before doing the rear side DT cuts - just eliminates an error.

Just a note: I've really abandoned DT's in plywood. For utility drawers I use plywood but I do a rabbet on the sideds and 1/8" dowel pins or screws and plugs.

I think you're going to find for just a few drawers, the set up time and aggravation factors are not going to be worth it.

Robert, did you see that Edward is talking about sliding dovetails?


Jon:
You are correct; it is a sliding dove tail I plan on doing.