How do you join your top and back plates? A Jig I Made.

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Diane Kauffmds
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Joined: Sun Mar 09, 2014 8:13 pm

How do you join your top and back plates? A Jig I Made.

Post by Diane Kauffmds »

I used to join the top and back plates by an arduous ritual, where I clamped a straight board, then semi clamped another, while placing the wood to be joined, just right, so that when I pushed on the center seam, it would "snap" together.

If that explanation sounds arduous, it was even harder to perform. It had to be set up just right, which took a very long time. I had 2 seam failures as a result. Sometimes the seams came out perfect, a couple of times the glue got dirty, even when using waxed paper. I don't like leaving things to luck. So, I made this frame.

I've joined 3 tops and 3 backs. All 6 pieces were textbook perfect. I had an extremely hard time locating the joint on all 6.

I have to admit, I made errors while making this jig, but I plan a second jig, so I'll refine it a bit. It's made from Baltic birch.

I use 1/4" parachord, which I weave around each slat in a figure eight, 3 times. Each time the chord is passed under a slat, it goes behind a 1" long piece of 1/4" diameter, smooth zinc rod, which is glued into holes at the bottom of the slats. After making 3 figure eights, I go onto the next slat. The jig is 24" square, but I'm going to narrow it to 20" wide, to make it more manageable. Also, I should have made the "legs" higher, to make it easier to wrap the chord behind the 1 1/2" zinc metal rod pieces (the chord is passed behind the 1" that protrudes).

The boards are joined by using triangular slats of wood. In the video I provided, susan uses 2 triangular pieces, one from each direction, per slat. I use one. One is sufficient and does a stellar job.

I got the idea from this YouTube video. Mine is not as well executed, but it works like a charm. https://youtu.be/TR7S5vdM60w
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Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
johnnparchem
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Re: How do you join your top and back plates? A Jig I Made.

Post by johnnparchem »

I do it like you do, but I bought my jig. Yours looks great,
Danl8
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Re: How do you join your top and back plates? A Jig I Made.

Post by Danl8 »

That is a nice jig, Diane! IIRC, the rope and wedge technique goes back to the lute makers of the Renaissance. Very effective. I did a simple jig using daisy-chained rubber bands (pictured in a July 28, 2015 post). After spending a ouple of weeks with John Hall I adopted his green tape technique. Last week, I forgot to notch one side of both tops and also had a devil of a time finding the joint. Won't forget that next time.
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by Diane Kauffmds »

Danl8 wrote:That is a nice jig, Diane! IIRC, the rope and wedge technique goes back to the lute makers of the Renaissance. Very effective. I did a simple jig using daisy-chained rubber bands (pictured in a July 28, 2015 post). After spending a ouple of weeks with John Hall I adopted his green tape technique. Last week, I forgot to notch one side of both tops and also had a devil of a time finding the joint. Won't forget that next time.
I forgot to notch as well. I did the 6 plates, one right after another, and I didn't think about notching.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
phavriluk
Posts: 554
Joined: Mon Jul 09, 2012 9:49 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by phavriluk »

Diane,

This is inspiration to build a new tool...

Glue used? Regular Titebond, I'm guessing, would set up before the joint was fully compressed. Titebond 'extend', maybe?

And rough dimensions? I don't want to build a tool bigger than it needs to be.

Thanks!
peter havriluk
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by Diane Kauffmds »

phavriluk wrote:Diane,

This is inspiration to build a new tool...

Glue used? Regular Titebond, I'm guessing, would set up before the joint was fully compressed. Titebond 'extend', maybe?

And rough dimensions? I don't want to build a tool bigger than it needs to be.


Thanks!
I used original Titebond, but I screwed everything together with 1" drywall screws. It ain't coming apart. Lol

The entire thing is 24x24". I should have made it 20" x 24". You want it wider than what you're joining. The flat wood up the middle is only about 8" wide. It's only purpose in life is to provide a flat surface to support the seam. The parachord does all of the work, and quite evenly, i might add.
Last edited by Diane Kauffmds on Sun Aug 06, 2017 5:02 pm, edited 1 time in total.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Diane Kauffmds
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Joined: Sun Mar 09, 2014 8:13 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by Diane Kauffmds »

I'm going to take photos of the bottom, so you can see the metal that I used to control the chord, and the stand. I promise to have the photos posted by tomorrow.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by Diane Kauffmds »

Here are more photos. I made this jig on the fly, with leftover wood from other projects. It's not the most precise.

Okay, the one mistake I made was placing the center seam board, which is 8" wide, and 24" long, on top of the already made frame. The plywood is 1/4" high. I noticed a slight bend to one of the tops as I was joining it, as the top had 1/4" drop to the slats. It didn't hurt the top or seam, but I corrected this by cutting more 1/4" plywood, to lay atop of the bottom slats, ensuring that the prospective top or back plate, would be evenly supported from the bottom.

The measurements for the bottom supports are in a drawing I made for you. If you make this jig, add 2" to the height of the bottom supports, to make it easier to put the chord behind the metal pins.

The metal pins, are simply 1/4" wide, smooth zinc rod that I picked up from home depot. I cut it into 1 1/2" pieces. I drilled 1/4" wide holes, 1/2" deep, put CA glue into the holes, then installed the metal pins. Since this is plywood, i clamped each drill area, on each side, before drilling the hole and installing the pin. This ensured that the plywood didn't split on me.

I had four, 14" wide by 2 1/2" pieces of plywood. I drew a line between opposite corners, and cut each along the line, into 8 triangular slats, to use for tightening the chord around the boards. I ended up only needing 4. The boards do not have to be tightened on each side. One side suffices.

I drilled a 11/16" hole in one end of the jig, in a bottom support, to run the 1/4" parachord through. I tied a large knot behind the hole. On the opposite end, I installed a 4" long metal rope cleat, to anchor the chord after wrapping. I picked it up at home depot as well.
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Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
phavriluk
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Joined: Mon Jul 09, 2012 9:49 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by phavriluk »

Sorry, I asked an ambiguous question. I intended to ask what glue was used on the plates being joined. I'm always surprised how fast regular Titebond grabs and I think it would grab faster than I could wrap with line and insert the wedges.

Thanks!
peter havriluk
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: How do you join your top and back plates? A Jig I Made.

Post by Diane Kauffmds »

I use original Titebond to join the plates, and HHG for the rest of the construction. It takes about 5 minutes, from the time I put glue on each board, to when I use the triangular slats to tighten the chord. I get very good squeeze out, even with the passage of a little time.

It looks really involved, but it's not. It doesn't take much time at all to wrap the chord. 2 figure 8's per slat is plenty. But, even with wrapping 3 figure 8s per slat, I get good squeeze out.

After adjusting the pressure on a top or back, I can move the jig anywhere to get it out of the way. I sit it upright, on end, with a plate in it.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
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