Falcate Laminating Jig

[woodrat]

I thought that I would post this here to show how I laminate my primary falcates....I modified the jig from one that I did originally from Paul Lamberts description. He used bungee...I found that it crushed the edges of the wood....I know I should have used a sacrificial outer non glued laminate...but in the end I had some t nuts and some bolts and knocked up this. I planed the laminated this time instead of putting a sanded surface together so it will be interesting to see if they are stiffer. I spread techniglue on the laminates and weapped the gladwrap around them and did the clamps up...done!...I did not even have to hot bend them...but I dont expect that will be the case with the secondaries......

Cheers

John

[Kamusur]

Ah good ol cold molded, an underrated and underused method i reckon, so simple and great for multi repros. John if you don't mind what timbers are the veneers and what are your future plans for them? ( i have probably missed a build thread ),

Steve

[woodrat]

Hi Steve, These are Red Spruce from a couple of bits of bracewood that came with a couple of red spruce tops that I bought from a guy on eBay in the States.
I have made 3 falcate braced guitars now and am really impressed by the power and complexity of the sound from this design if Trevors design principles are employed accurately...(not too hard to land it in the right place)
I have two tops yet to put on guitars and I will be making more but the red spruce ones will be going on the Brazilian one that I am making from the Wotnot I sawed up a couple of months ago. (see Wood Rebirthing thread)

Cheers

John

[woodrat]

Just pulled it out and the laminations are nice and tight....techniglue is great for this operation...now will clean up a side and rip it down the middle to produce two matching falcate braces....

So you could say "it worked!"...simple and effective methof to make falcate braces. It is the third method that I have tried by the way....

John

[ozwood]

Nice one John ,

Now that's a nice Jig !!!

Here are some Pics of my quick and dirty Jig for those who are quick and dirty .

Makes mine look decidedly agricultural.

Cheers,

[Kamusur]

Thanks John excellent. A possibility too with thin veneers, grain orientation tweekage and some water based glue to soften those cellulose fibres you might be surprised what shape those laminations can be "helped into" ......secondaries?

Steve

[woodrat]

Hi Steve, some good ideas there. I made my secondaries with 4 laminations last time of 1.25mm to give me a 5mm brace but still had to heat bend to get my old growth Douglas fir to go around the corner. It did make the process easier though.
I think I will make another jig like this for the secondaries.

John

[woodrat]

Steve, your musings got me thinking about the secondaries and I wonder if instead of trying to cold laminate them if you put them in the microwave for 1 minute or so, whether they would bend after heating the water in the wood. At 45%RH the wood should have a MC of 8%....I think I will have to do an experiment....

John

[woodrat]

Paul, That looks like that wide tough blue plastic strapping on your jig (?) ...that looks like it would protect it well from the bungee. I should have done that the first time....but I went on to make the screw pressure one which works a treat....

Cheers

John

[twopotscreamer]

Did the microwave help?

[woodrat]

Hi Twopot, the microwave experiment didnt work for me.....but no matter the cedar bends so easily with heat from a hot pipe. I dont think there was enough moisture in the timber...nevermind...

John

[jeffhigh]

I did mine like Paul's.
I did however just use cheap garden twine rather than bungee cord because I was using epoxy and I figured the squeezout would ruin the expensive bungee first go.
Worked fine.

[Kamusur]

Thats a shame John i thought the microwave was a goer, anything i stick in there comes out soft and pliable and mostly inedible. I should send over a plate for testing.

Steve

[luke_lee]

Hi All,

I just thought I would add a photo of the jig I made to glue up my solid linings. I use a two part mould with a positive and negative and clamp the linings between them, its very easy and quick (after you make the jig). I added flat sections so it is easy to get clamps all around it. I used my construction mould to copy (by routing) the outside shape. I used my bracing template for the inner follow by a rebate router bit to get my 6mm offset inwards. This two part jig can be applied to laminating Falcate Bracing.

Luke

[Kamusur]

Hey Luke that cant be right you are only using 2 clamps what gives?

Steve

[Allen]

That type of mould will work for waisted glue ups. In fact it's the type I use for my laminated solid linings. But try as I and Micheal might, you have a hell of a time getting something without a waist to pull up tight. No matter what we've done when using the plug for clamping, we get 100 % failure in what you would call the waist area (for lack of a better term). The waist shape in a congenital instrument helps get that clamping pressure to the middle of the layup.

I'm really liking Johns idea. When I get some time I'm going to have to give it a go.

[woodrat]

Thanks Allen, I have made a jig for the secondaries too (will post pic soon) and the glue lams that come out of them are excellent so I am glad that I have made them this way. T nuts are great devices for jig making.

John

[Dominic]

I've tried making a couple of sets. With both sets of braces I clamped one end of each piece to the form and with my heat gun held in the vice, I heated the strip and bent them one at a time, one over the other. I was using KBP but it should be as easy with other stock. Before I glued up I had pretty good fit. I need a better clamping method. But it was simple to use the heat gun to bend the strips over the form.
Cheers
Dom

[needsmorecowbel]

Noob Falcate question. Do you radius the falcate braces in the same manner as you radius X braced braces? i.e. in a radius dish?

[Dominic]

No, you just press them into the dish and they tend to hold shape apparently. And Trevor mentions it is much easier to get the geometry right if they are flat. I'm about to do my first one so I have to trust in what others tell me.
Cheers
Dom

[woodrat]

Dom, They just squash in there and stay put when the epoxy is cured....the CF tow cannot stretch so therefore they keep their shape....
....how are you going with your falcate build?

John

[needsmorecowbel]

Cheers guys that's interesting

[Dominic]

Dom,
....how are you going with your falcate build?

John

Slowly, I am perfecting all my moulds and bending forms for my falcate model, getting them super accurate so I can use a template to shape the head block and get away from too much fiddling. And testing wood for top linings. I had some silver ash which bends really well so I've cut up a heaps of them. I've also been having trouble with humidity this year so I have finally got myself a small dehumidifier in a spare bedroom and moved all my wood in there. Took a few weeks to reduce the moisture content of the wood but seems to work well and seems to stay around 45 so I can now work whenever I want. But it has been unusually high in ACT this year and I lost a lot of time

My first falcate one is a cocobolo cutaway. Lots done but not the soundboard due to above. But now I can get stuck into it without fear of it drying out later on. Also have ready a set of IRW, and sets of Ovankol and paudak. Plus I am nearing finishing a zebrano Hauser classical commission and then I have a nice small set of tiger myrtle which is also for a Hauser. So I am making progress but on a wide front. So rather than do one fretboard, I do 5 or so.
Cheers Dom

[Trevor Gore]

Interesting thread here.

In the book I mention using a band clamp (framing clamp), which is what I still use. Has anyone had problems with that, or are you just trying different ideas/working with what's in your shop?

[Dominic]

Hey Trevor, I tried band clamps but I only had the cloth ones not the spring steel ones. I have an nice idea for using wedges like on top and back joining plates. I'll make some pictures and post them.
Cheers
Dom