Acoustic Guitar Construction

I am working on a scratch build mahogany OM. I wanted to try and do as much myself as possible here so it is not a proper OM shape but something I came up with. I made the side profile templates too, but these are pretty close to a standard Martin OM (i think..). I have neglected to take many pictures of the work but here are a few I did take.

I took Daniel P's advice and got the Veritas honing guide, and then setup two new planes (a Stanley 5 1/2, an Acorn No.3 smoother). With the exception of some tearout getting the mahogany back and sides to thickness they made the work easy and fun. The boards I got came in at about 5mm thickness (maybe the sides were 4mm) so it took quite a bit of planing to get everything down right (about 2mm for the sides / 2.5mm for the back / 2.7mm for the top). I really enjoyed it though.

I was going to make a bending iron with aluminium pipe and a heat gun but just as I ordered the parts a decent, unused bending iron popped up on ebay, which I promptly bought. It is a Caramillo bending iron (solid aluminium, heats up in about 10 minutes or less). I had a few practice pieces of mahogany to get used to bending with, I got the hang of it quite quickly I think, and bent the actual sides with only a bit of charring and 1 small tear. Took a bit of time to work out what bends to make to match my template - but again really good fun. I didn't soak the mahogany, just kept spritzing with water as and when it dried.

I am doing tapered bracing again but have made the x braces much thinner and will compensate by leaving them higher than in my L00 build. The top sounds lovely and I can't wait to hear the thing. The top is sitka spruce and was about £35 I think. Splitting the brace stock from a billet was quite un-intuitive for me. Got there in the end though.

The back has a bit of figure but I have improved things with a zipper back strip.

I am halfway through making the neck. Scarf joint was fine (just used a big japanese cross cut saw and made the cut slowly). I knocked the pocket for the truss rod out with a chisel and this took a while. First job that I will find a power tool solution for on the next build. I am going to make the tenon and get the neck roughly profiled today. Make the mortise was easier than I thought (I am using the kmg style bolt on neck), again done with a saw and chisel but didn't take long.

Once the tenon is made (and I can check it against the mortise) I can close the box, just gota glue the neck block and kerfing. I will use wider side reinforcements this time round. I took the sides real thin in a few places ! I still have to make the bridge and fretboard from scratch (both ebony) but I have the kmg fret slotting templates on the way, and will probably buy a router bit to make the saddle slot. I could dremel it but feel like the dremel is too fragile for ebony - any advice on this?

Few other specs -

24.75 scale length
15' back radius / 40' top radius
rope purfling with white plastic binding
binding on the headstock (and possibly an inlay if I feel up to it!)
3mm fretboard dots
tru oil finish again, this time I might pore fill it.

First major oops of the build!

I had cut the 88.5 degree angle into the heel cheek / tenon area, had finished fitting the tenon into the mortise, and then realised I had measured the angle from the wrong side and would now my 180 degree angle would be 181.5! I had left the tenon a few mm long so was able to correct that easily enough, but had to cut a couple mm off the heel cheeks to redo the thing with the correct angle. I *think* this will still be ok, and that the neck will still meet the body at the 14th fret. I might extend the bridge plate down 2mm just to be on the safe side.

I checked and double checked and was certain I had it the right way round .. oh well.

Just gota get the inserts into the tenon now. I have these ones - http://www.theinsertcompany.com/brass_s ... r_wood.php

M6 x 10mm, with matching bolts and washers. Will these work ok? Need to craft a way to insert them into the tenon too.

Those inserts look like they will work fine. You can drive them into the tenon by first drilling the proper sized holes in the tenon, then I use a cut off bolt and two nuts on the bolt (be sure the bolt is long enough for the 2 nuts, the insert and some extra length to chuck it into a hand drill), screw the insert onto the bolt, tighten the nuts snug to the insert and chuck it in the drill. The slots in the insert are NOT for a screw driver and they go into the hole first, then drive the insert into the hole. Done.

Thanks Tim and Ken - will get them installed tomorrow!

ken cierp wrote:viewtopic.php?f=14&t=194

Hey, that was a blast from the past!