I don't think you'd go horribly wrong with any of them, Kenny, although like you said, the Forrest will leave your wallet pretty light.

About the biggest factor I've found regarding a clean cut with my Incra IBOX is to always make sure you have uncut backer board behind the cut when you start a new project.

If I were choosing, I'd probably go with the Freud, but that's not based on anything but brand preference and price.

 

Thanks Rich. I totally agree on having a fresh backer on the jig. I forgot to slide it over one time and that was a lesson well-learned ;-) My thinking is pretty much along the same lines as yours - Freud has always treated me well and their price is as good as any. The only reason I'm not just going that route is that the higher tooth count on Oshlun caught my eye…

 

Personally my first go to are dovetails on my Leigh D4R.

For smaller quick dirty, I have a vino and then reach for my Incra box. Then my preference is the router table,

using the router bit with a decent sacrificial backing board gives me the best cuts… I use an 8mm TCT spiral cutter.

for best results.

If the router table is configured for another job, I use a Freud SBOX8 Box Joint Cutter set,

which does both 1/4" and 3/8" joints…. and is bloody easy to store in a drawer and loose amongst other tools,

(had trouble finding it for this photo shoot).

Hell, I should keep my answers short…. Looks like Rich and you have already sussed out the Freud...

 

You want dead flat bottoms, perfect sides and easy to set up width (no shims) then use a router table. You can even gang cut all four side at once for fast and accurate cutting.

Have made tons of box joints this way.

Most important is to get your material an even multiple of the joint size so everything ends on a full notch or finger. No half teeth as they complicate the fit and look odd.

 

You want dead flat bottoms, perfect sides and easy to set up width (no shims) then use a router table. You can even gang cut all four side at once for fast and accurate cutting.

- Madmark2

That's what these blades are designed to do. My personal preference is the router table too, but not because of any false notion that blades are an inferior performer.

One thing I will say regarding blades versus bits is that with the router bits, you need to be careful to keep the board from moving when the bit starts to cut. It will want to move sideways. Like I mentioned in my blog post on the Incra IBOX, I added a strip of 220 grit paper for added friction. I doubt that would be needed if using a blade.

I gotta say MM, I'm shocked, SHOCKED I tell you, that you don't have an Incra IBOX. You being the Incra fan that you are.

 

Cutting on the table saw is just faster and I prefer it for the reason that Rich points out about the wood wanting to shift. Also, I like being able to tweak the joint size with shims in the stack so I can fit the joints to the material and not visa-versa.

Which brings me to an issue I forgot to address in the OP… I plan to be able to tweak my cuts using shims between the two blades when I don't want exactly 1/4" or 3/8". I assume there is no issue with this but please correct me if I'm wrong!

 

Did. Found my sled was bigger & better & easier to clamp. It's about the only tool of theirs that got tossed under the bench.

 

Which brings me to an issue I forgot to address in the OP… I plan to be able to tweak my cuts using shims between the two blades when I don t want exactly 1/4" or 3/8". I assume there is no issue with this but please correct me if I m wrong!

- HokieKen

Since their teeth overlap in the middle, I can't see any problem with using shims.

 

You want dead flat bottoms…
- Madmark2

Yes, but the way I drink and the missus feeds me… it'll never happen.

Now for the shims… when using the iBox and a 1/4" or 3/8" blade, I can't understand why you need to shim… surely that 1/10000000th. of a mm would not make too much difference…

'gree with the router trying to toss the wood around if you forget to hold it… but I can get my gut around the router table easier than the tablesaw… The worst thing you can do is have options (router of TS?)... they play with your head and if they start playing with mine, I'm in more trouble than worrying about my "f(l)at bottom".

 

The only issue I've found with shims (and this falls under any dado stack) is their propensity to get hung up in the root of the Acme thread of my Unisaw spindle. for the sake of experimentation (potentially dangerous experimentation) to get true flat bottomed grooved, I have tried using chippers only without the side blades cutting bat wings at the edges of the grooves. I knew this would cause tearout so I had well clamped waste wood at the entrance and exit of the grooves. Much to my surprise it worked well but I had fixtured everything in such a way to ensure I wouldn't become collateral damage if something flew apart. I'd do it again for onesies, twosies but I'd be shopping for a proper solution like you are if I was planning on any quantity.

 

Now for the shims… when using the iBox and a 1/4" or 3/8" blade, I can t understand why you need to shim… surely that 1/10000000th. of a mm would not make too much difference…

- LittleBlackDuck

It's not a matter of the size of the cut being that precise, since the jig is designed to be adjusted TO the cut. The one time I could see shims is if you wanted to tweak the finger sizes to get a better layout along the joint.

 

Now for the shims… when using the iBox and a 1/4" or 3/8" blade, I can t understand why you need to shim… surely that 1/10000000th. of a mm would not make too much difference…

- LittleBlackDuck

It s not a matter of the size of the cut being that precise, since the jig is designed to be adjusted TO the cut. The one time I could see shims is if you wanted to tweak the finger sizes to get a better layout along the joint.

- Rich

Exactly. I'm just thinking if I wanted to do 5/16" fingers instead of 1/4 or 3/8. Or if I had 2-3/4" boards, I might want .275" fingers etc.

 

The only issue I ve found with shims (and this falls under any dado stack) is their propensity to get hung up in the root of the Acme thread of my Unisaw spindle. for the sake of experimentation (potentially dangerous experimentation) to get true flat bottomed grooved, I have tried using chippers only without the side blades cutting bat wings at the edges of the grooves. I knew this would cause tearout so I had well clamped waste wood at the entrance and exit of the grooves. Much to my surprise it worked well but I had fixtured everything in such a way to ensure I wouldn t become collateral damage if something flew apart. I d do it again for onesies, twosies but I d be shopping for a proper solution like you are if I was planning on any quantity.

- bigblockyeti

Interesting, I've never had that problem with shims in my dado stacks. Using the chippers makes good sense but two teeth isn't ideal

 

I bought the Freud set shortly after they first came out (intro special at about $60 delivered). I have not compared it with other similar sets, but I consider the Freud set "perfect", at least beyond my initial expectations and far more versatile than just cutting box joints.

The teeth are large chunks of carbide and accuracy of the cut width is dead on (.250" and .375"), A single blade will cut about .200 IIRC.

Neat feature besides the perfectly smooth/flat/square dados/grooves is the exceptionally clean edges on crosscuts.

Normally when cross cutting dados, I'd often make scoring cuts with my WWII blade so as not to get any grain tearout from the dado blade. Even with the square edge, flat top, very wide cutters on the Freud set, there is no/zero tearout (this is on oak and walnut). I even have used it to cut thin channels into veneered wood (my "crazy" clock face project) without and chipping.

Versatile enough that I haven't bothered with my dado set for some time. I'll just use the box joint set and first establish the shoulder cut (on tenons), then clean up the rest by sliding the work piece away from the blade. Of course limited to 3/8" of material removed at each pass.

One "downside" is it has a different offset from the arbor than my regular blades, hence I have dedicated ZCI plates for the saw and nicks in the rails of my aluminum miter gauge fences from forgetting to check for blade clearance before cutting (Doh!)

Definitely a specialized use blade, but far more uses than just making box joints.

 

I guess doing them by handtool takes too long…....

 

Yes Bandit it sure does I enjoy hand tools but only when I enjoy them. And cutting box joints isn't one of those tasks.

Thanks for the detailed write-up splintergroup. The feedback on the crosscutting probably just pushed me over the edge. Crosscuts is another time when I despise using a dado stack.

 

Kenny - I'm with LBD - I haven't used a dado stack to make box joints since I got the Leigh D4. My biggest issue was the slight lines from the blades across the top of the cut. Plus shimming the stack was pain too, as was the indexing.

Of course, I was using a standard dado stack because I'm too frugal and don't have room for a prima donna box cutting dado stack.

 

Normally when cross cutting dados, I d often make scoring cuts with my WWII blade so as not to get any grain tearout from the dado blade.

- splintergroup

Unless you've actually experienced tear out, I wouldn't worry about extra steps like that. Those blades have a negative rake angle which ensures a clean cut, and also renders a ZCI unnecessary.

That said, your work is beautiful, so however you go about doing what you do must be right.

 

would one of those also be ok for cutting grooves for splines? i need to pick up some new stuff as well so interested in the info here.

 

Don't see any reason why not SMP. If you're tilting the blade though, you'll have to be careful of clearance with your throat insert and it's an 8" blade so you won't have as much reach. If you don't need them quite that wide, any FTG blade should work. I just like to be able to cut box joints in a single pass.

 

I do angled cuts with the box set for corner "thingies", watching out for throat plate clearance is part of the process one best never forget to do 8^)

I do angles for corner legs to better interface with prefinished box parts

Rich: The main reason I do the scoring cuts before hogging with the dado set is when the surface is veneered. My dado set (Freud 8" SD) does well, but the side cutters often will screw with squirrely grain. I'd rather do the extra work (not always guaranteed to do it cleanly) then blow out an edge that no one will ever see 8^)

 

Rich: The main reason I do the scoring cuts before hogging with the dado set is when the surface is veneered. My dado set (Freud 8" SD) does well, but the side cutters often will screw with squirrely grain. I d rather do the extra work (not always guaranteed to do it cleanly) then blow out an edge that no one will ever see 8^)

- splintergroup

That makes sense. Like I said whatever you're doing is working. Amazing stuff.

 

Don t see any reason why not SMP. If you re tilting the blade though, you ll have to be careful of clearance with your throat insert and it s an 8" blade so you won t have as much reach. If you don t need them quite that wide, any FTG blade should work. I just like to be able to cut box joints in a single pass.

- HokieKen

no just a straight cut for corner splines like this below. i only had an ATB blade when doing this , but Rich helped me pick the fill in materials. mainly i want a blade to make box joints AND be able to use it for 1/4" flat bottom splines:

 

no just a straight cut for corner splines like this below. i only had an ATB blade when doing this , but Rich helped me pick the fill in materials. mainly i want a blade to make box joints AND be able to use it for 1/4" flat bottom splines:

- SMP

In that case, a box joint blade would definitely be what I would get SMP.

...
I do angles for corner legs to better interface with prefinished box parts

...
- splintergroup

That's a really cool joint for the 3-piece corner. I'll have to remember that one

 

Now for the shims… when using the iBox and a 1/4" or 3/8" blade, I can t understand why you need to shim… surely that 1/10000000th. of a mm would not make too much difference…

- LittleBlackDuck

It s not a matter of the size of the cut being that precise, since the jig is designed to be adjusted TO the cut. The one time I could see shims is if you wanted to tweak the finger sizes to get a better layout along the joint.

- Rich

Still find the shimming is like shimmying up a greased pole (no malice intended for the Polish nation). Better layout for box joints? Sheesh… Nice layout and detail is what Moses and Mr Leigh invented dovetails for… if they used box joints for the ark, half the animals would have refused to board.

If you have shim issues, try a freud dial-a-width.