Thread: Great New "Martin" Acoustic Building Manual

Great looking guitar Andy.

Put a few more pics of it and the other two.

A great guitar by the looks Andy.

Sweet looking guitar Andy, and I agree about Hard Shellac. I think kits are a great way to get going with lutherie, certainly in acoustic land.

Some more details please, binding?, I assume the kit came with bent sides and mostly thicknessed? how about some pikkies of the rosette,

Sebastiaan

Thanks fellas for the comments, much apperciated. Here's a pic of the bracing which is your typical Martin scalloped bracing. They need some shaping to get them to look like the blueprint. The sides come pre-bent, but can be a little out of whack until you get them into a mold. The back from this company, Stewart MacDonald, is joined. These ones came with cupped ends that I had to steam flat before gluing up the neck and tail blocks. I think Stewmac tends to keep a lot of stock in air-conditioned warehouse which seems to present problems with Indian Rosewood. You can also get some cupping along the edges of the rims and sides. A scraper sorts these out.

Kits aren't really just gluing part A1 to B7, there's heap of work to get a finished guitar. I feel they're closer to being a builder at Martin or Taylor etc, but instead of just doing one job on the line, you get all the parts and have to assemble them accurately. There's leeway with the bracing. On the two I'm building at the moment I'm "forward shifting" the bracing pattern to the vintage pre-WW2 pattern



This is the closest pic I've got of the rosette as well as the Herringbone binding.



I'll attempt to get some more pics up of the two I have in progress. They're an Honduran Mahogany 000 12 fret and Indian Rosewood Dread, if you fellas are interested.

Lovely build there, Beachcomber
Looks to be very clean work

With the two you're currently building, what is the overall benefits in pushing
the bracing forward?

From what I know about forward shifting or vintage bracing, Martin changed their X bracing pattern on both OM’s and Dreads around 1938. Before this period the centre of the X braces was 32mm from the soundhole. Martin moved the centre back approx 12mm. They did this to rectify problems with warping behind the bridge. Martin built their OM’s and Dreads for medium gauge strings and still do. I’ve also read that it was quite common for many players back then, particularly bluegrass players, to use heavier gauges for more volume. This wouldn’t have helped warping either.

A smaller triangle formed between the braces and the bridge plate on the “back shifted” pattern stiffened the top. The downside of this move was lowered volume by reducing the flexibility of the top. Through the fifties and sixties they further beefed up the bridge plate, changing from maple to rosewood and almost doubling the size of the plate. This cut even more volume.

Another part of forward pattern is to also widen the angle between the top arms of the the X braces from 98 to 100 degrees. Along with that the tone bars start from the same position on the treble X brace, but radiate at an angle of around 120 degrees towards the bass X brace, compared to around 110 degrees on modern Martins.

The real purists also don’t use the flat wide upper bout brace, between the shoulder brace and neck block. Many guys believe this is also a volume killer. This brace wasn't used on the vintage Martins. I’m not going that far as I still want some strength in that area and I’m not convinced that all that much vibration is happening in that area of the top anyway. But I could be proven wrong.

I have played a two modern Martin D18-A's [ rrp $10,500 AUD ] which is their most faithful replica of a vintage braced Dread, Mahogany B&S with an Adirondack top & bracing, side by side. One was really loud with heaps of headroom and no breakup of sound. The other had been played less, but was on its way to being very similar to the other.

Andy

Beautiful clean work there ...
I reckon your ready for a scratch build looking at that instrument.

and thanks for the heads up on the book ...Looks interesting.

gratay, thanks for thumbs up on my modest building abilities, but from what I've seen in the short time I've been around I'm more than impressed, gobsmacked would be a better description. The quality of original design of guitars that are pure sculpture makes me realise it's all way out of my league. All I've done with electrics is building a replica '52 Tele from WD parts, which is about as basic as you can get.

My main interest in starting this thread was that I have a passion for Martin style guitars. I wasn't sure whether kit acoustic guitars had ever be covered on the forum.

I always thought that while Stewart MacDonald had a good building manual some vital parts of the build weren't explained all that well. In particular getting the dovetail right with the correct neck to body angle. I've got all the main books on acoustic guitar building, but Bill Cory's manual has the best description I've ever come across.

Btw for anyone interested I've just found that Martin are now shipping some of their kits outside the US. However, their building manual is pretty sketchy.