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I've been reading what I can about finger joints on the web and here. My project does not require finger joints, as those the wood was fine on the areas that had finger joints. I was thinking about joining some interior wood in the rear for fun. However, it appears as though the options for creating them are somewhat unclear. 

 

1. Jig-template: I have the Porter Cole jig that is designed for box joints, but can be used for end-to-end square tooth finger joints. While they are not the nice, narrow fingered joints that are seen on the cars, they can work and are pretty easy with that jig. 

 

2. Finger joint router bit: I have not used these before. I have been reading about them and it appears there are a few problems-

    a. people appear to have difficulty with getting the joints to match up properly. I have seen the use of thin pieces of plastic to raise the second piece of wood to properly form the joint, although this takes some trial and error. 

    b. raising the router bit by a small amount to create the adjoining joint in the second piece of wood. Apparently this adjustment can be very, very small. 

    c. there is concern for the safety with some of the adjustable bits, which some people have said have come apart in some instances

    d. The maximum heigth of these bits appears to be 1.5 inches, which would limit the width of the joint that can be used. 

3. Using a table saw and a jig

4. A commerical finger joint machine: appears to be cost prohibitive for the small amount of time I would be using it. 

 

Rather than experiment with a process that would lead to failure (and expense with a dead end project) I would rather pursue the option that is most reliable and used by those of you who have performed them successfully and start to practice/get experienced with that method. 

 

Any thoughts would be appreciated!!!!

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Posted (edited)

After talking to Dave (New old wood), who has a tremendous amount of knowledge regarding finger joints and has himself a spiffy finger joint machine, I have concluded that a bush leaguer like me should probably stick to using a jig to create joints, if one is going to pursue finger joints. Dave is additionally a very nice guy (runs Simply Southern Woodworking) for any of you seeking to have parts made or an entire woodie rebuilt. I will ALWAYS rely upon an expert like Dave when I want something to look super spiffy or there is any degree of three dimensional curvature, but doing the wood on simpler stuff is just fun to do (not to the extent that Tom Boehm does either) for amateurs. 

 

Porter Cable has a nice jig that clamps the wood in place very nicely and allows one to make end-to-end finger joints (although it is made specifically for box joints in making dovetail drawers and boxes) using the jig and a straight or v-groove router bit. The depth of the "teeth" using that method is maximally one inch, given the maximal cutting depth of the router bit with either the straight or v-groove bit. 

 

Of course, one cannot achieve the nice, long, narrow "teeth" of the old finger joints that were made on most of the woodies originally. I am somewhat lucky, in that the International I am doing now had very few finger joints. Those that were present were intact with the original wood (thank you barn storage and lack of voracious termites). Apparently there is not a cutter/router bit available to use mortals that can create such finger joints. The best approximation is a true finger joint cutting machine and blade system, which is prohibitively expensive (and big) unless you are going to be doing those joints on MULTIPLE projects. Most of us are probably only going to restore 1-2 woodies during our lifetimes, which makes such a purchase somewhat impractical. 

 

The router finger joint bits as well as using a dado blade on a table saw requires very small adjustments and quite a bit of trial and error to achieve a product which looks good and useable. 

 

The finger joint jig and use of a straight or v-groove router bit to make shorter "toothed", yet easier and more readily reproducible finger joints appears to be the route for your standard idiot, like myself, who delves into such things for amusement and not self torture. My project really does not require finger joints not already in place, but I wanted to add some ash pieces on the rear interior walls which would look cool with finger joints, thus the interest. 

 

Feel free to disagree/scoff/laugh or whatever; however, those are the conclusions I have drawn which would make finger joints with the least hassle, reproducibility and frustration for one who does not routinely make them. Like Clint Eastwood said, "A man's got to know his limitations"!

Edited by blind pew (see edit history)
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Here is another idea you might like. My car did not have finger joints originally. The original joinery used what I call spline joints. I used a dado blade on a table saw to make the slots for the splines. You have to do it with precision but I did not think it was that hard to get good looking joints. It is important to have a method of clamping so as to fully pull the two halves together when gluing. Look at the temporary clamping blocks on the upper right corner on New Old Wood's latest post. 

DSCN6532.JPG

Edited by Tom Boehm (see edit history)
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I agree with your assessment, unless you have the proper equipment or access to it, milling joints one at a time and adjusting the height mechanically will be a big hassle.  I've seen guys do it using a single cutter and adjusting the height using a cnc setup.  The following pictures show my set-up, which admittedly is heavy industrial quality.  The cutter itself, which I bought through an ad in the Woodie Times years ago, is a massive hunk of tool steel with a 1 1/4" bore, which I spin on a 7 1/2 HP 3 phase shaper with a sliding table.  Even at that it's the scariest thing I've ever done in 47 years of woodwork.  BTW, the cutter was supposedly made by Wisconsin Knife Works, an old, respected name in cutter knives, but when I asked them about it they disavowed any knowledge of it ever having come from their shop!  That being said, it does work great and gives me clean, tight finger joints, even though after a session with it, I'm exhausted and have a few more gray hairs!

Phil Stofanak

IMG_0145.jpeg

IMG_0146.jpeg

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Holy crap! That is quite a machine!

 

Yes- for those of you who have done (and will do) a lot of finger joints, that is something that can be very useful. For us "hackers", it is out of our league as far as skill set and expense for limited use. 

 

Tom- those are beautiful joints for a table saw and dado blade!

 

I have been practicing the last few evenings using the Porter Cable jig and a 1" and 1.5" straight cut router bit. This actually makes nice looking, easily reproducible joints with very little fuss and can be mastered quickly, which is important in not wasting tons of nice ash. 

 

Thanks for the inputs!

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I've got all my stuff at my farm, which is about 300 miles away (just left yesterday). That's where I have my woodshop and the woodie. 

 

I'll get back there within a few weeks and post some pics. 

 

Thanks very much for the input, guys!

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Hello all,  I’ve been following this discussion because I also need to make a few finger joints in replacement wood for an early Chevrolet utility vehicle. Fortunately for me, they will not show so square corners are acceptable.  I came across this YouTube video that I believe has promise at a low cost.  Rather than initially buying the flat-top blade, two stacked blades may suffice.  I did find that the flat top blades come in 5/32” and 1/4” widths.  The front fence may need to be more substantial as well.  I’d appreciate your thoughts.

Thanks, Mike

https://www.youtube.com/watch?v=P7WBeXRufWg

 

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Rexville, simple box joints, as you show have been around forever. The issue you will have is clamping your part to allow for the depth that you need to make joints like the beautiful joints like Tom shows. The more complex the part, the harder it will be to make tight joints. I have been building furniture using mortise and tenon joinery for years, but curved parts can be a real pain to clamp. I would contact Tom to pick his brain about how he did his joinery. When it comes to correct finger joints that were used on station wagons, you're talking about a different animal. I have seen production photos of the jig's that were used in the Ford Iron Mountain plant that are massive and take two people to use. The pictures of Phil's cutter and machine are no joke and I'm sure he will tell you that clamping and chucking the piece to be cut is the biggest issue.

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Thanks for the response.   I agree with all of the comments about massive cutting heads on large machines with unique clamping capabilities for the correct joints used on our wagons. When I  started researching the Porter Cable jig mentioned above, I came across the attached video.  What intrigued me was how the home made sled could be used on a table saw to quickly index each individual cut and align the first cut on the mating piece.  By limiting each groove and finger width to 5/32” or so, deeper grooves might be able to be achieved with lesser clamping forces and greater stability. A steady rest,  unique for each piece, temporarily attached to the front fence could help.  I’m going to experiment with the concept and will report back.

 

Again, I appreciate the feedback.  Thanks, Mike 

 

 

Sent from my iPad

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Rex, I don't know where you are located but in my area there are several woodworking shows that air on TV during the week. A show called the Woodsmith Shop built a jig almost the exact same as you show and plans are available from their web site.

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