Laminating sides

Beau Hannam Ukuleles

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So here i have two versions of laminating sides using molds.
The first mold I made was a full 4" deep (ie- deeper than any uke side) which was to be used as a dedicated laminating mold. I wanted to make more but realised that making more this way is a waste and takes up twice as much space on the shelves.

My second version is to simply add (with screws) a temporary layer of 3/4" ply to my 5 existing tenor uke molds- far less lpy is used and the sides are laminated using the mold they will stay in until boxed up.

Full depth + an extension piece at the end.
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New version with temporary layer that after lamination is glued, is unscrewed and saved for the next batch of laminated sides. The same mold is used for the build duration for the sides that were bent in that particular mold (in this case #2). I Always put the temp layer on the "top", and mark 'A' and 'B', so it is impossible to accidently bend two bass sides.
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Different angle showing some simple registration marks so the correct temp layer goes onto the correct mold number and correct side.
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Ply strips with cork so the inner side doesn't get bruised. The other way (which i'm yet to try) is to have a more fuller inner insert to clamp two- but once you make one of these you have to stick with the same thickness of layers in your sides...im still fine tunning what i like in side thickness- at the moment im .070"-.070"-.020"- the 3rd decorative layer isn't necessary if you use a good looking wood for the 2nd layer.
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How i place the cork/ply strips- clamping gets tight so get creative. Also note- when started using the temp layer, i dont bother to use an extension piece of ply- but i do make sure i put a cork/ply strip RIGHT at the end.
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Full clamps
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3 layers
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I use titebond 3 for sides (its a bit stronger then red cap titebond. Epoxy is also great for this but its toxic and expensive and titebond works 100% perfectly. Note- i spread it evenly over the side (i dont leave it like this!)
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Cutaway lamination.
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12 sets of side, hand bent- thats 36 pieces of wood!
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I once had an idea , of using an inner tube in the centre of the mould with a lid on top and bottom and pumping it up to compress the sides against the mould walls..I tried it with a mountain bike tube and it worked..sort of :D
 
Someone on instagram queried me calling this method (actually, the result) "solid wood laminate" asking why it isn't simply "ply".

In a book called 'Bending wood' (which is a collection of articles form Fine Woodworking mag), they define layered wood as:

Lamination when the grain of the layers of wood are all in the same direction- ie, you have a piece of wood, you cut it into strips and glue it back together again as it was (but bent, or not). It doesn't have to be the same species of wood, just the grain direction.

Plywood- when the wood layers are at 90 degrees to eachother.
 
Plywood, alternating wood grain with odd number of layers.

Two layers, not grain aligned as the outer maple is quarter sawn and the inner spruce layer is flat sawn.

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The inner-tube method was described by an old woodworker Charles Haywood in his book on veneering. He used a firehose and foot pump in a box. Brilliant way to do it and a lot more consistent than your current approach Beau - voids will have an effect....

I've ordered the book from Amazon and when I get it Beau will send you the relevant section. You really are making this hard for yourself.... Bit of old fashioned English cabinet making fairy dust will soon have you sorted!
 
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This way (in your picture) is easier for clamping but in doing it this way you constrain yourself in regard to the total thickness...assuming you then put these sides into a regular mold. Working from the build mold you can vary the final thickness of the sides at your leisure. This isn't a problem if you know you will always use, say, a layer at .070", and a layer at .060".
My inner layer (rather middle layer) is either fat or quarter sawn- whatever i grab from the pile. Either poplar, walnut or mahogany (spruce, rosewood, anything works really as long as its stable)- it all gives the same result and is all "laminate" rather then "ply". Also, laminate can be either an even or uneven number of layers, but ply must be uneven.

Plywood, alternating wood grain with odd number of layers.

Two layers, not grain aligned as the outer maple is quarter sawn and the inner spruce layer is flat sawn.

wifbqV2.jpg
 
I've heard of the fire hose method but not seen it done - im sure a quick detour to youtube would remedy that!

"Bit of old fashioned English cabinet making fairy dust"- what a lovely sentence!
 
Thanks for the vids Kevin. They reminded me why I don't laminate sides they were such torture for me to watch because there were so many processes! There is such a simple way of doing this that doesn't involve a vacuum but controlled pressure. I haven't got time to mock it up but as soon as I get the 'bible' excerpts I'll make them available to anyone who is interested. I used to use a vacuum bag for veneering flat and shaped work. It's much harder to get this right on high forms and it is why that chap's vacuum table is so large.
 
i looked at the vacuum method and admit it seems best and very suited to this type of pressing....but it cost a bit (like $500?) to get an initial set up.

Using vacuum to do bridges also looked interesting but a little involved. I said to myself, 'So how hard can it be?'

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Back in the 1970s I had so much trouble hand bending dulcimer sides, so I tried to laminate veneers in the mold. It was no fun. I can't remember my setup, but I ended up with bubbles on the outside veneer as well as a general cupping of the sides across the grain, most likely because I didn't have enough clamps. Later I also used this method to make the sides, back, and top of a resonator guitar. Over time it became disaster that I had to buy back, but it wasn't the fault of the laminated wood. The only thing I'll laminate today is the cutaway portion of a Florentine cutaway
 
I can't remember my setup, but I ended up with bubbles on the outside veneer as well as a general cupping of the sides across the grain, most likely because I didn't have enough clamps.

My layers are .070" + .070" (sometimes with a 3rd layer at .020") with as many clamps/ply strips as i can squeeze in so no bubbles. As I mentioned to Pete, even if there are some slight gaps, I STILL have an outer layer that is only a single human hair thinner then a full thickness side (I would call .080" a full thickness side).

I've not experienced any cupping, even after laminating and leaving them on the shelf out of the mold for months- they slide straight back in the mold they came form with no spring back. Marvelous stuff!!!
 
That is a very thick finished side. Are you working on the Australian model of guitar building where all the energy is in the top? Can't think why you would go to the trouble of laminating...

I've also bought a motor cycle inner tube... Going to mock up a press to see if the theory works...
 
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A note on the inner-tube thing. I did this to veneer the inside of banjo rims. Worked OK, but I found that to increase the pressure, particularly along the edges, it helped to have top & bottom plates with a bolt between them. Then I could inflate the tube, it would start to bulge over the edges of the banjo rim, and then I could squeeze the top & bottom plates down to really put pressure on rim from edge-to-edge.
 
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