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Ditson ReTop
Posted: Wed Mar 03, 2010 10:53 am
by Joe Sustaire
While I'm in a retopping mood, this ladder braced Ditson I built suffers from too thin a top, 0.080", with too simple a bracing pattern to make it work. I had added a ladder brace in front of the bridge plate to stabilize the belly problem at one point and it has stabilized but the sound is just too harsh, thin and un-melodic to coin a phrase.
So this is the guitar.
And here you can probably see the belly and the downtip of the bridge.
I used an iron to heat the bridge and fretboard overhang, protecting the top with foil wrapped cardboard. Worked them loose with pallet knives and removed the pick-guard with the blow dryer.
Since this top isn't any good the shielding to protect the top wasn't necessary, but I thought it would be good practice.
Then I set the router up to route back the top down to the kerfing.
And worked it loose.
And here is the thin top with it's ladder bracing. You can see the brace I added thru the soundhole in front of the bridge, and note how I got it on there crooked. I'm sure that was intentional!
Maybe that's why I don't get to work on any vintage Martins.
All for now,
Joe
Re: Ditson ReTop
Posted: Wed Mar 03, 2010 11:13 am
by Jim
Interesting, Joe.
I can't imagine doing a better job myself with that added brace, but perhaps if you had landed it tight and parallel to the bridge plate, it might have helped a bit more. I think I can see where the thin top bowed in and out around the fretboard too, so it really was a problem of a too-thin top. A good lesson for me, as I'm tending to make some tops on the thin side, and I was thinking some extra-heavy bracing would make up for it. Guess I'd better think again.
Thanks for posting. I'm sure you'll be happy with the result and it will sound better than vintage Martins.
Jim
Re: Ditson ReTop
Posted: Thu Mar 04, 2010 1:54 am
by Lefty
Joe,
You da man! I can't find time to finish an instrument and here you are taking your'se apart.
Oh, and where did you get that electric Iron?
Lefty
Re: Ditson ReTop
Posted: Tue Jun 01, 2010 7:09 pm
by Joe Sustaire
Well we've had a very wet spring here, humidity thru the roof and I've learned my lesson about gluing on bracing and closing boxes when the humidity isn't right. Finally had a day I could do the bracing and this is what I came up with.
Ladder bracing glued on with HHG.
The A bracing around the soundhole notch into the head block and the upper transverse brace will notch into the kerfing, all other braces die out before the kerfing leaving the top free to move. Spruce bridge plate with rosewood patch for ball ends of strings.
And a couple of shots after carving and tapping. Sounding good.
This top is about 0.115". I measured the top I routed off and it had places that were 0.070" and 0.080", so no wonder the tone sucked and deformed from string tension.
Joe
Re: Ditson ReTop
Posted: Tue Jun 01, 2010 7:28 pm
by Joe Sustaire
Yes I'm behind on my documentation.
Got a good day to close the box, taps good. Then on to binding. No pics.
I decided to string this up in the white so glued on the bridge with HHG and after a couple of days found a chance to string it up.
Put a pearl dot in the hole in the bridge where I had tried a bridge doctor to support the thin top, didn't like it.
B/mahogany/B and B/maple/B purf for the soundhole and purfling.
And by golly it plays and sounds much much better than what it did, lot of voice.
So I've already broke it back down for finishing and am also refining the neck carving, it feels a little chunky compared to the way I carve them now.
Thanks for watching,
Joe
Re: Ditson ReTop
Posted: Tue Jun 01, 2010 9:22 pm
by Pat Foster
Good deal, Joe!
It's always interesting and educational for me to revisit early builds.
Pat
Re: Ditson ReTop
Posted: Tue Jun 01, 2010 10:07 pm
by George
Great job Joe. I need to get back to working on some instruments.
George
Re: Ditson ReTop
Posted: Tue Jun 01, 2010 11:23 pm
by Garry Hallam
Joe, well done on getting this put right. Very good practice for repairing, you pulled it off superbly.
I love the look of the binding and rosette channels, they look very natural.
Garry