Thread: #1 Acoustic Build

Black Wattle eh? It definitely looks good anyway.

My problem with the shed is that I can't really afford to lose any more space to a controlled cabinet, even a small chest, so control the whole shed is my next option. Just need to stop whinging about it and do it...

Made up the bracing boards for the back and soundboard today. I've used a piece of 32mm chipboard that Bunnings sell as an unfinished bench top. One side has the back curve and the other side has the soundboard curve carved into it. A quick splash of shellac to seal it up and they'll next be trimmed to the shape of the boards and sealed around the edges.

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I was initially concerned that the different densities of the chipboard might cause a problem but it actually helped quite a bit with getting a (close to) symmetrical carve.

Too much work and nowhere near enough shed time lately...

Fortunately I managed to get an hour or so in today so feeling a bit better. The bracing board has been trimmed to shape and sealed up, ready to go so today's efforts were directed towards sizing up some spruce for the back bracing.

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I've been watching the back panel curling up and down over the last week or so and must admit I was pretty surprised by how much it moves. The little demonstration it gave allowed me to justify to the better half, all the work and cost that will go into insulating and controlling the shed.

My selection of little end mill bits turned up today also. Keen to get those onto the soundboard but need to settle on the rosette design first. I'm think of a very simple contrasting wood inlay and maybe a couple of purfling strips around that.

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Looking good Steve - thanks for posting.

cheers
Stopper

Not much progress on the #1 build over the last couple of weeks. I did manage to spend an afternoon shaping the back braces but that is about as far as I've gotten.

It was time to stop whinging and get the shed sorted out so all my efforts have gone in that direction. Of course I decided to paint the shed floor on the wettest Sydney weekend for 8 months apparently... Here is a pic after I had etched the concrete and trying to get it dry overnight so I could lay a coat of paint down the next day. Not fun, at this stage all of my tools were in the back yard covered with tarps and we ended up getting about 39mm of rain before I could get them back in the shed.

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For some reason the shed decided to start leaking in one corner between the slab and the course of bricks that the frame sits on. This is the first time I've ever seen any water in there so I ended up leaving that corner unpainted for now. I'll get back to it later...

In the end the floor came up quite well. I was unable to get it 100% cured before I was forced to get everything back into the shed so there is some marking where the machines were first placed but I managed to get most of them into their normal positions so shouldn't be a problem.

That was last weekend. This weekend I've started the crap shuffle once again as I work on insulating and lining the walls one at a time. I've got two walls done now and hope to get a third done tomorrow but need to get the electrickery sorted out for the A/C before I finish off the last wall. It's looking pretty good but I have lost what seems like quite a bit of crap storage with the wall cavity and noggin shelves now inaccessible.

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Final item for today is my new hygrometer. Picked it up on Ebay for a good price but it seemed to have quite a large error when compared to the local readings from the Bureau of Meteorology. A little bit of googling led me to the salt calibration method which it is now undergoing. The first run indicated that it was out by about 8% so it's been adjusted and is now stabilising to check a second time. I would like to try get hold of some Magnesium Chloride salt to check it at a different humidity level but haven't been able to find any just yet.

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looks good Steve, you'll be glad you went to the effort when it's finished ,are you going to seal the walls? Salt calibration sounds interesting I will have to look it up . cheers Rob

Originally Posted by stevemc32

Final item for today is my new hygrometer. Picked it up on Ebay for a good price but it seemed to have quite a large error when compared to the local readings from the Bureau of Meteorology.

I wouldn't be too worried about your hygrometer not agreeing with the BOM's humidity readings. It's not unusual for humidity readings taken at locations a few kms apart to vary significantly. During the winter here in Adelaide the BOM will quote a humidity of 70% for Adelaide while my hygrometers (3 of them) are reading close to 100% humidity outside my workshop.

Thanks Rob, the salt calibration is quite simple, here's a link I found when searching Hygrometer Calibration

When you say seal the walls do you mean painting them or sealing all the gaps? I kind of like the plywood look so I wasn't planning on painting them but I know they will slowly darken and gather a lot more dust if unpainted. Still deciding...

Martin, I'm just over a mile and half from the nearest automatic weather station so I always considered it to be quite an accurate indication of the local conditions. It's showing a 25% drop in the RH over the last hour though so I don't think it's the right time to be comparing the two. It's also located right beside a nuclear reactor so your advice to not pay it so much attention is very likely valid.

Just read the calibration link, good read. Painting them was what I meant ,I agree the plywood look is good , I did the same,I sprayed it with clear,I dont know if it was worth it ,I can only see the roof now mostly. cheers Rob

For luthiery work, calibrating with the potassium chloride is the way to go since it is right in the RH range we want.

Good thinking Jeff.

Just ordered some Potassium Carbonate to create a 43% RH environment for calibration. It was much easier to find the Potassium Carbonate than the Magnesium Chloride I was looking for earlier. I've ordered it from an online photo chemical store and should be here in a few days.

Got another wall of the shed completed yesterday and have someone coming over to install the a/c this week. Looking forward to getting back into the build.

So the shed is now insulated, lined and air conditioned ready for the summer. Glad to have that completed but I still haven't got around to moving all of my crap back in there just yet. Maybe time for a serious crap cull...

Anyhow, conditions have been just about spot on for the last couple of days so I decided to have a go at getting the back braced up this evening. Nothing spectacular, all seemed to go together ok after a quick dry run with the clamps and wait and see how it turns out tomorrow.

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I must admit, I still don't seem to have gotten the concept of the glue stick / chisel for cleaning up glue squeeze out. Every time I go near the squeeze out with either the stick or chisel I just end up smooshing it all over the place which I'm sure is going to end up worse than if I'd just left it there.

Got the back braces shaped up today with the block plane and some sandpaper. A little scrap of mylar helped to keep the block plane off the inside surface of the back plate.

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I shaped a curve into the back of the two sides and the next step will be to cut some linings and glue these onto the sides ready to join the back. I decided I wasn't happy with the kerfed linings I made previously and found some nice timber to make up another set. Not sure what type of timber it is but it will do the job.

Here's a quick pic of the new air con in place along with a small clamp rack I banged up yesterday to tidy up the shed a little.

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Little bit more progress today on #1.

Here's a pic of the nice piece of wood I'm using for the linings. It was scavenged from an old architect's plan drawer cabinet. I can't really remember where this piece fit into the cabinet but it will do the job here. I cut from it a couple of 2.5mm quartersawn linings and the rest was sawn at 5mm widths for kerfed linings.

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The two linings were shaped and sanded, then bent into the required curve for a test fit and subsequent gluing after giving the inside of the guitar sides a quick sand with 220 grit to remove the bending marks.

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Still haven't worked out the glue squeeze out stick...

Got a bit further today.

Made up a small sled to cut the kerfed linings. I saw this on one of the videos that someone linked to earlier and it's definitely a better method than I had used before. Keeps the fingers much further away from the blade.

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Next up, fit and glue the back.