Jumbo OM Build for Tom
12 May 2020  | Tags: build log, jumbo OM, vintage
I have been working on a jumbo OM for my friend Tom. This is an updated body shape for me, slightly bigger than my old OM, with a wider lower bout and longer body. It is somewhere inbetween a Martin OM and a Dreadnought. Should make for a loud guitar with great range, whilst still comfotable to sit and play for a long period of time.
The guitar has an engelmann spruce top, indian rosewood back and sides, south american mahogany neck and rosewood fretboard and bridge. The styling is reminiscent of a vintage Martin - herringbone rosette and purfling, ivoroid binding, simple headstock design.
The top is very pale and the back is very dark, and the contrast is wonderful. Both are really tight grained and strong, and I wish I had a dozen more sets of this indian rosewood as it is great quality.
The new body shape has the upper bout and soundhole shifted up towards the neck, leaving a vast lower bout which should act as a brilliant speaker cone and generate a lot of guitar noises. I have kept the neck and headstock a little heavier to compensate for this, so the guitar should feel balanced when rested on the players knee.
I have a new workshop, which gives me a bit more space and light. It is still pretty tiny, and I find my messiness grows to fit my surroundings, so I am still balancing tools on top of wood on top of tools. I need to work tidying up after each job.
Here is my adjustable go bar deck I made. I previously relied on a bag of cam clamps to glue braces, but this is quicker, easier, funner. I won't be going back to the cam clamps. I am using beading/moulding from a DIY store for the clamping sticks.
Here is the body, ready to be cleaned up and have a neck fit on. The cat likes to sleep up here but I kicked her off so I could take the photo.
And here is what the guitar looks like now! I am close to the final few coats of oil . The silking in the spruce is great. I keep the oil coats super thin and apply 3 per day over the course of a week. It leaves a beautiful finish. Once the final coat is on I will leave it a week to cure, and then glue the bridge and get some strings on.
UPDATE 23/05/20
The guitar is finished. The sound is right where I wanted it: loud, punchy and crisp. The body shape is comfortable to play and the vast lower bout seems to be giving each note a lot of richness and sustain. It looks nice too.
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