Introduction: DIY "Silent" Practise Guitar
I've just taken up the classical guitar and am going to have to put in a great deal of practise. Unfortunately I live with my family in a two bedroom, Victorian era flat. There is always someone on the other side of a door or thin wall to annoy, especially at night or in the early morning. I need some way to practise more quietly at least some of the time. I don't want to spend much money as I may discover I hate classical guitar in a few months. There are four of options:
- Buy a cheap electric guitar and use a headphone amp. The problem with an electric is that it is metal stringed and has a different width neck. Also I really don't like the look, feel or sound of electric guitars - although you can get an amp to simulate an acoustic sound quite well if you pay for it.
- Muffle a classical guitar by filling the body. People have tried this. Here is a great video of it being done. Unfortunately it doesn't work well because much of the sound comes from the sound board itself vibrating rather than the hollow body amplifying it.
- Buy a Yamaha SLG200N. My favourite option but unfortunately they cost about £600 and I can't justify that. My budget is more like £60. Maybe in a year or two ...
- Build my own poor man's Yamaha SLG200N. If you look at the Yamaha, apart from all the sophisticated electronics and wonderful craftsmanship it is "just" a cut down classical guitar with a piezo pickup. Indeed the early models (SLG100 which still fetch £400) just had a basic on board amp.
Obviously I chose option 4 here. This is how I built my silent type guitar with some tools but no workshop, some DIY skills but no craftsmanship, some money but not enough to do it properly.
Step 1: Materials and Tools
I don't have a workshop. This project has to be done in the common stairwell of our flat (the really messy stuff) or in the living room.
- Work bench.
- Drill with wood and metal bits.
- Dremel multi tool with wood and metal cutters plus sanding attachment (you could use a pad/keyhole saw but it would be harder work).
- Various clamps
- Other normal DIY bits
- A cheap/old guitar. In the course of a weekend I bought 3 guitars for a total of £40 from people I found locally on Gumtree. The one I am learning on was actually only £10 but looked the best. The one I cut up to make silent was £20. These are the kind of guitars you can buy new for around the £100 mark. They are beginners have-a-go-and-see-if-you-like-it guitars. Obviously don't do this to a good guitar unless you really want to.
- Piezo pickup and preamp. These are cheap and plentiful on ebay if you don't mind waiting a week or two for them to ship from China. I paid just £9.52 for a Fishman 201 including shipping. It fitted my needs because it is flat rather than curved like many and is a good brand.
- 6mm MDF sheeting. I had this left over from a DIY project but it is really cheap to buy.
- A 1 metre aluminium rule. I had this as a spare but they can be bought on-line for < £10
- Four nuts and bolts. I had these nice knurled knobs that I scavenged from a skip 20 years ago and have been in my "knobs and knockers" box ever since.
- 20mm plywood sheet for the jig. This sheet came off the street. Builders are always leaving offcuts for us borrowers to pick up. Could have been any study wood.
- Set of new D'Addario Classic Nylon strings £5.99
Step 2: Building the Jig
When I was thinking this through I struggled with how I would keep the alignment of the guitar. First of all I was just going to cut it up but when I looked at how real luthiers build guitars I realised everything is bolted to a jig throughout assembly. So I decided to bolt the existing guitar back to a jig before I glued the new body to it thus maintaining the bridge-fretboard relationship.
Fortunately the 6mm MDF was the same thickness as the distance from the top of the fret to the front of the guitar body so by making a template as shown and laying it on top of the very sturdy and flat 20mm plywood I could make a primitive jig.
Step 3: Chopping It Up
Acoustic guitars seem like living things. The thought of cutting one open feels like killing and gutting an animal. I recommend taking the strings off a day or two before as it loses the life force and it is easy to take the saw to it.
- I flipped the guitar on its back.
- I placed the jig on top of it and drew around it with a marker pen. Then down and around where the neck joins the body.
- I also drew a cut line about 10mm below the bridge.
- Then I ran around the cut line with a wood blade on my Dremel. There was a rather pungent smell from the varnish.
- I discarded the remains of the body as I couldn't think what to do with it.
- Finally I screwed what remained of the sound board to the jig as shown.
Step 4: Modelling the New Body
MDF (medium density fibreboard) is actually pretty dense compared to the wood used in guitars and shouldn't vibrate so much when glued to the remains of the sound board and bridge. It is also very easy to work with for those with few skills and little time.
I built a box shape body the top of which would be glued to that soundboard covering the hole. Once I'd worked out how the box would lie I removed all the internal strutting from the soundboard in that area and sanded it flat to make a good surface for gluing.
Step 5: Gluing New Body
The main messy work over I moved into the living room to glue the part together. This was done in two stages. firstly the new soundboard and attachment to neck then, after 24hrs for glue to cure. The rest of the box was assembled and allowed to cure for another 24hrs.
Step 6: Liberating Guitar From Jig
Once the glue was well set I moved back to the messy area and used the Dremel to cut the body from the jig.
I removed all excess wood, including the overhang of the neck brace.
Three old strings were attached to see if it worked at all. This was the point of no return. If it fail it was in the skip and I'd not have been writing this Instructable but it made a sound and didn't snap so was worth finishing.
After general sanding the MDF got three layers of mat vanish left over from the kitchen surface.
Step 7: Final Assembly
The silent guitar was now just a stick and so impossible to hold correctly. I looked at buying some aluminium to make supports but, as I stood holding it in the shop I realised it was just like a 1 metre rule without the markings and more expensive. It just so happened that we had two identical rulers so I sacrificed one to become the support frames cutting and bending it to the right shape then bolting it in place.
Fitting the piezo was straight forward. There are model specific instructions on line as well as many generic example videos.
As you can tell I'm no guitarist but it seems to play OK. The action is a little high and I'll need to set it up differently as I move out of first position but that is more to do with correcting the saddle for the piezo than guitar geometry I think.
The actually components cost me £35 but I used a load of bits and bobs I had already. I also had to buy the plug amp for £8.99. When I set out I thought I'd do it for less than 1/10th the cost of buying a Yamaha i.e. £60. I'd rather have a Yamaha than 10 of these though!
It was fun to make and that is the main thing.
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