[Cherryville Chuck]

FJ vs BJ...

.

Also known as finger joint and splice joint. You'll find more references, especially older ones, referring to a box joint as a finger joint since it appears as if you laced your fingers together. If your criteria is to name according to the application as in calling the finger joint a box joint then you should also call the one that splices lumber end to end a splice joint. Unfortunately there is no consensus as of yet. Maybe in a few years. The trend seems to be moving towards what Stick said but be cautious as the historical norm is otherwise. Other terms include tapered finger joint instead of just finger joint and splice joint.

 

[1fizgig]

Gah! Sorry Chuck, I appreciate the info, really I do. But nobody seems to want to answer my actual question.
Can anyone explain why several of you are proponents of the table saw rather than a router table for this job?

 

[CharleyL]

When making box joints with the box joint router bit shown above, your box height will be limited by the height of the bit and number of cuts that it makes. It might be possible to flip the board and repeat the cut from the opposite edge to double the board height, but the board height and bit settings will need to be very accurate, or your center box joint won't go together.

Using a straight router bit or spiral bit will let you cut one at a time and using a jig like the photo posted, you increment the board however many times is needed to cut the box joint all the way across the full width of your work piece, so the height of your box can be anything that you desire.

I prefer using my table saw to cut box joints because it's easier to make the cuts with reduced tear out of the edges of the cut, and I can make a box of any height. The table saw blade teeth only cut the joints in one direction, but the straight router bit cuts forward on one side of the bit and backward on the other side of the bit, at the same time. Avoiding tear out of the cut edges is very difficult because sacrificial edge protection is required on both sides of the work piece. The table saw only requires the sacrificial edge protection on one side of the work piece, and it can be re-used, because the blade to sacrificial strip position is the same for every cut made during that setup.

Charley

 

[Stick486]

Okay, yes, I get the difference. What I'm asking is if the box joint router bit be used to create the joints required for the new box, why would you use the table saw over this method?

THAT'S the question I want answered

I said yes you can but it has size limitations..
the bit is only so tall and that's the controller of the width (not thickness) of the board you want to or can use ... (the max will/can be only twice the height of the bit w/ a bit of work)

we want KISS/MISS here...

 

[Stick486]

Gah! Sorry Chuck, I appreciate the info, really I do. But nobody seems to want to answer my actual question.
Can anyone explain why several of you are proponents of the table saw rather than a router table for this job?

the TS gives you a wider range of joint sizes and widths of material..
easier set up, less waste, work and breakage...
did I mention mega cheaper too...
way more cuts w/ a TS blade then ever possible w/ a router bit..
hence.. TS for production... RT for occasional shallow use....

however the router bit is a 1st choice asset if you had, say, a really wide slab of 4, 5, 6 or even 8/4...
use your bit on the end grain 1st and then resaw the slab into slats...
cutting the slab to to slat length to start is a big plus...
it'll be just like down town...

 

[Cherryville Chuck]

Excactly the reasons Charley gave. To expand on what he said a bit and to help explain why the router wants to tear grain: the widest part of the bit is through the dead center. So as the bit goes through your wood when the bit gets to its widest part at the middle the force the bit is exerting on the wood is 90* to the point of contact. On the left side of the bit that's straight towards the wood but on the right side it's 90* away from the wood so there is nothing on that right side to resist the shear forces on the grain unless you are using a sacrificial facing board. The opposite happens on the way out. The shear forces are 90* on the left side. As Charley said the force exerted by a table saw are straight back so the chances of ripping part of a finger off are reduced to close to nothing and the cut is usually cleaner.

That's why I always use a table saw for that joint and as Stick pointed out it's cheaper to use a TS than a router. The above explanation also applies to other routing jobs like rabbeting too. The closer you come to having half the bit into the wood the more likely you are to experience tearout. In physics whenever you have rotary motion the force applied is always tangent to point of contact.

 

[1fizgig]

Thanks guys, now I understand. I knew we'd get there eventually!
I now also understand better use cases for the box-joint bit, not that I'm likely to be working with larger pieces and resawing at this stage.

Hm, so I'd have to be very accurate still with my TS jig when making it though, right? That's one of those things I get more nervous about.

 

[Stick486]

thanks guys, now i understand. I knew we'd get there eventually!
I now also understand better use cases for the box-joint bit, not that i'm likely to be working with larger pieces and resawing at this stage.

hm, so i'd have to be very accurate still with my ts jig when making it though, right? That's one of those things i get more nervous about.

what for...
Just follow the directions and don't get all worked up over it...

 

[DesertRatTom]

Well, let's toss in one more. I chose the ibox jig, which adjusts to the blade's total width. You can use a dado stack of any width you wish. You fit one side of the jig "feeler" to the blade, then turn a small knob until the opposite feeler just kisses the other side of the blade's teeth. This pretty much eliminates the setup hassle. You use a backer board for tearout. You could also get one of the blades that cuts either 1/4 and 3/8ths box joints with ease and you can use just about any width board you intend to use. Box joints are cut a little deeper than the thickness of the board you're using. Then you sand or saw off the slight excess. Japanese pull saw is best. Here's a pix of the jig: You can also use it on the router table.

Here's a video.

Here's one using a router table:

 

[PhilBa]

Yeah, that looks like a good way to go.

By the way, you can use a flush trim router bit to cut off the fingers that stand proud. Works really well.

 

[CharleyL]

Yes it does. I usually trim off the excess this way, but I found that double sided taping a spacer under the box side being trimmed flush, keeps the overhanging un-cut ends from holding the box up off the router table and at a slight angle. This avoids scalping the box side that you are trying to cut flush. After one side of one corner is trimmed flush, I then peel this spacer piece off and move it to another side that has un-cut pins facing down. You need to keep the box side that is facing down parallel with the router table, or flat on it for the flush trim bit to cut only the excess pin length and not scalp the box side.

I'm tired, so I hope this makes sense.

Charley

 

[Stick486]

some other plans...

.

 

[Cherryville Chuck]

Thanks guys, now I understand. I knew we'd get there eventually!
I now also understand better use cases for the box-joint bit, not that I'm likely to be working with larger pieces and resawing at this stage.

Hm, so I'd have to be very accurate still with my TS jig when making it though, right? That's one of those things I get more nervous about.

You do need to be accurate or the fingers may be too tight or too loose. The first home made one I did was just a fence attached to runners that fit in the miter slots. It had no adjustability. It was also a pain to use because anytime I used it I had to get my dado stack the same thickness and I mean exactly the same thickness. I got rid of it and went to an Ibox because like Tom said you can easily adjust it to match the saw blade thickness instead of the other way around.

The way Ed Pirnik from Fine Woodworking did it with his home made jig is much easier. He made what I made but then he added another fence which he clamped to the first. That gave him the ability to change the spacing on the fingers to get the proper fit. Whether you are using a router or a table saw the jig works pretty much the same.

 

[1fizgig]

Well I have no dado stack for my table saw, so I'd have to get a flat tooth grind blade and work it a little different, but that's ok.
It's not currently on my highest priority list, so it gives me time to investigate options. I imagine at some point I will want to make some box joints.

 

[Bstrom]

So guys, why wouldn't you use a finger-joint router bit?
I understand the use of the table saw, but I'm confused as to why you wouldn't use a bit in the router? Fully adjustable, repeatable..... Yes, you'd need a backing block to reduce tearout (no different to the table saw it seems), but I'm struggling to understand they "why not"?

Seems to be some confusion between what is called a finger joint and a box joint. Two different joints for different uses.

I built a box joint jig this weekend and the plans posted were most helpful. Pretty easy as I got it right the first time...the Freud Box Joint blade set does a great job.

 

[Cherryville Chuck]

There is lots of confusion about the nomenclature. If you go back in time the square fingers were always called finger joints. The ones to splice lumber end to end were called either a splice joint or tapered finger joint. Most of the older woodworkers who have gone through woodworking schools still call the box joint a finger joint because that was what their teachers called it. When this issue came up a few years ago I did some web searching and about 4 of every 5 references to the joint called it a finger joint. I'm starting to see more references calling it a box/finger joint using both terms together so that no mistakes what is being referred to. We had one new member a year or so ago who had just purchased a finger joint router bit with the plan of making boxes with it only to find out that he had purchased the tapered type which only splices lumber together. One should never assume which finger is being referred to. I think in time we'll move to the definition you refer to Brian but we aren't there yet. I still refer to a box joint as a finger joint because that's what I learned to call it when I was a kid. Maybe the problem started when mills starting taking trim ends and splicing them together to make longer lumber and decided that you can't call both types fingers but that's exactly what they are. It's just that one type is tapered and the other one isn't.

 

[Bstrom]

There is lots of confusion about the nomenclature. If you go back in time the square fingers were always called finger joints. The ones to splice lumber end to end were called either a splice joint or tapered finger joint. Most of the older woodworkers who have gone through woodworking schools still call the box joint a finger joint because that was what their teachers called it. When this issue came up a few years ago I did some web searching and about 4 of every 5 references to the joint called it a finger joint. I'm starting to see more references calling it a box/finger joint using both terms together so that no mistakes what is being referred to. We had one new member a year or so ago who had just purchased a finger joint router bit with the plan of making boxes with it only to find out that he had purchased the tapered type which only splices lumber together. One should never assume which finger is being referred to. I think in time we'll move to the definition you refer to Brian but we aren't there yet. I still refer to a box joint as a finger joint because that's what I learned to call it when I was a kid. Maybe the problem started when mills starting taking trim ends and splicing them together to make longer lumber and decided that you can't call both types fingers but that's exactly what they are. It's just that one type is tapered and the other one isn't.

FYI: Freud refers to their square dado blade set as made for a box joint. Guess that’s where I settled on the term. As long as you know what you’re doing with the tools it doesn’t really matter, even tho my insistence on clarity ruffles at any conflicting terminology. The ‘splice’ reference makes the most sense for joining lumber longitudinally while ‘finger or box’ fits the joinery description well.

 

[Stick486]

There is lots of confusion about the nomenclature. If you go back in time the square fingers were always called finger joints. The ones to splice lumber end to end were called either a splice joint or tapered finger joint. Most of the older woodworkers who have gone through woodworking schools still call the box joint a finger joint because that was what their teachers called it. When this issue came up a few years ago I did some web searching and about 4 of every 5 references to the joint called it a finger joint. I'm starting to see more references calling it a box/finger joint using both terms together so that no mistakes what is being referred to. We had one new member a year or so ago who had just purchased a finger joint router bit with the plan of making boxes with it only to find out that he had purchased the tapered type which only splices lumber together. One should never assume which finger is being referred to. I think in time we'll move to the definition you refer to Brian but we aren't there yet. I still refer to a box joint as a finger joint because that's what I learned to call it when I was a kid. Maybe the problem started when mills starting taking trim ends and splicing them together to make longer lumber and decided that you can't call both types fingers but that's exactly what they are. It's just that one type is tapered and the other one isn't.

you contesting my father's and and his father's word???
I selling tickets to this...