Finger Joints Question

[Rjcagnew]

Hi

I am looking to join some panels together to make a wall hanging tool cabinet, I plan to use box joints to do this. The panels are 3/4 birch plywood and approx 30 cm wide. I have read about various methods for doing this, the favoured appears to be making a jig for a router table. I have a router but no table. Is it possible to create a template on some thin mdf of the 2 different layouts needed by hand and then clamp these to the workpiece and then use a flush trim bit to create the joints ? I understand I would need to square the bottom of the joint with a sharp chisel. It seems to make sense to me but have not seen this method talked about? Or is this too much hassle and should just cut them all by hand ? Many thanks Richard

 

[carlb40]

Yes. I would make the jig similar to the ones used for table saws/ router tables, make sure you add the location finger too. Clamp the 2 mating pieces together - offset the one the distance of the intended thinkness of the fingers. Also clamp a piece of timber to the rear to give added support for the router. Then rout as normal. If you do it this way, so you are effectively routing the edges, the router bit will create a flat bottom so no chiseling will be required.

If that makes sense? If not i will add a drawing.

 

[Rjcagnew]

Hi Carl Thanks for your reply- I hadn't thought of cutting them with the router "vertically" so to speak but that makes sense. I was thinking of cutting them with a flush trim bit with the router flat on the surface of the board. Trying to work out what the jig would look like with the method you have described? Thanks again Richard

 

[carlb40]

Hi Richard.

Something like this

Nice and simple. Just a piece of ply/mdf with a guide pin/ stick the same thickness as the cutter you use. The guide could be fitted where ever you want the size of the fingers to be. The more accurate you make it the better the joints will be. Something like this might work better as a sub base, ie remove the base of you router and attach this directly.

 

[MMUK]

I take it you're planning to join the boards to make an approx 60cm width board? Could you not half lap the joint and use biscuits or dowels? Much easier.......

 

[carlb40]

I take it you're planning to join the boards to make an approx 60cm width board? Could you not half lap the joint and use biscuits or dowels? Much easier.......

Well from his description i think a tool cabinet might be on the cards

I am looking to join some panels together to make a wall hanging tool cabinet

So i assume it is for the corner joints? If so i'm not sure box joints will offer much in the way of strength?

 

[MMUK]

I take it you're planning to join the boards to make an approx 60cm width board? Could you not half lap the joint and use biscuits or dowels? Much easier.......

Well from his description i think a tool cabinet might be on the cards

I am looking to join some panels together to make a wall hanging tool cabinet

So i assume it is for the corner joints? If so i'm not sure box joints will offer much in the way of strength?

I gathered the cabinet bit Carl but wasn't sure how he was intending to join the boards. I just assumed they were to create a 60cm wide back panel

If it's as you say, I'd make the frame (ie; top, bottom and sides) with biscuit joints and fit an inset back panel also with biscuits.

 

[Rjcagnew]

Hi Carl

Yes its as you say tool cabinet with finger joints to join the sides to the top. I like your jig idea a simpler and much cheaper version of this

http://www.youtube.com/watch?v=74ACCW3kMDk

Thanks for the advice

 

[custard]

Picking the best method does depend on your level of experience. Finger joints are really best cut on machines, an experienced woodworker can do a decent job with a router and a simple jig, but it comes as a shock to a newcomer to discover just how painstaking you have to be with this method get good results. Plus plywood is notoriously prone to tearing out where the router cutter passes through, so unless you're really careful and have very sharp cutters the results can be a bit messy.

This is why most woodworkers would use biscuits. But a biscuiter isn't a cheap machine so I suspect a decent dowel jig might be worth considering.

One other thing, successful woodworking with man made panels (ply or MDF) depends to a great extent on your ability to cut the panels cleanly and absolutely square and to precise dimensions. You can achieve this without too much expense using a hand held circular saw running off a simple fence to guide your cuts, but like most things in woodworking putting the effort in early in the process, to make accurate jigs and practise the technique first, will really show in the finished result.

Good luck!

 

[Benchwayze]

Richard

I never tried cutting finger-joints, or dovetails in MDF. I find that even moulding the stuff leaves a woolly surface. I once used fingers in some marine-ply drawer boxes, and that was successful. Although when I'd finished, I felt it wise to drill down through the fingers for about an inch (25mm) and put a dowel into each side of the joints. As far as I know, the drawers are still in use, after 30 years!

Well maybe they've been dismantled by now, :mrgreen: but I never had any complaint.

http://www.youtube.com/watch?v=3xDXePtofxE

or:

http://www.youtube.com/watch?v=yLS7QjV3-WU

HTH

 

[Steve Maskery]

I really don't want to burst your bubble, but I think you are going to find it hard to do what you want to achieve. Plywood, even top-quality baltic birch ply, does not take kindly to being routed in this way, and the precision you need to repeat the cut over such a distance... well let's just say that it is challenging.
However, please document it, because it is something in which I, and I suspect many others, would be interested. If you do pull it off successfully then we will be suitably praise-giving.

I know you don't have a router table, but could you not lash up a cheapie, just some MDF hanging on your workmate and then use a jig like mine? You still have the issue of the material itself, of course.

http://youtu.be/eKEB-BIq9qI