A Pair of Ditsons

[Joe Sustaire]

Thanks Dennis, Hugh, and Luc, yes I'm ready to hear them sing!
This is the first time I've done the pin registration on the bridge, and it sure does help, no slipping and scrambling. It's definitely a technique I'll keep using.
And Dennis that's just el cheapo off-brand masking tape. Maybe why it didn't pull up any fibers. I guess with FP the shellac goes on in such a thin layer you just don't have a wet surface to creep under the tape, because it sure was clean.

Thanks again, I'm off to the shop,
Joe

[Eben]

Not only are these looking great, but...

Toothpick Registration would be a swell band name!



E

[MrZ]

They look nice,cant wait to tell us about sound.

Z

[Joe Sustaire]

Thanks for watching guys.

A little forward motion, got the ladder braced one together, strung up and playing. Sounds great, and plays good. Then a few steps backward, after a couple of hours playing I start looking it over closely, and the bridge is lifting on the back edge.

So, how about a few pics on bridge removal?







I mask off around the top to protect the surface from pallet knife marks.




Cut a mask from cardboard and cover with foil.



More layers of foil covered cardboard, to concentrate the heat from the old movie camera lamp on the bridge and shield the top.




Heating with the lamp, 2 to 3 minutes, then check with pallet knife. Took about 3 times, then the glue was soft enough to seperate, working the knife in carefully on all sides. The top stayed cool, so the shields worked.




And it came off clean.

Now why did my glue joint fail? I don't know, not clamped evenly? clamped to tightly, starving the joint? imperfect prep? who knows?

But we try it again, perfect sanding prep this time, clamps better aligned, not too much pressure, leave it clamped overnight, let it have a couple of days to cure before stressing. Keep my fingers crossed!!!

Also while looking closely at the lifting bridge, I noticed that the top is de-forming pretty bad. String tension is rotating the bridge, sinking the top in front of the bridge and raising it up behind the bridge. Now one problem is my neck angle needs a little adjusting. Too much height on the saddle needed to get enough action on the neck. There is a full 9/16" under the strings in front of the bridge, so that's increasing the torque on the top. But now look at the bracing photo.



I followed a pic of one of John How's ladder braced guitars, and added the bracing on each side of the sound hole. But seeing how the top is de-forming right off the bat, it's not going to work, sounds great but doesn't look like it will last long. Maybe John leaves his top thicker, I know he uses adirondack which is supposed to be very stiff, but this one definitely needs help. My first thought was that it needs a bridge docter to transfer the tension to the end block. And that might take care of it, but looking at how little bracing there is, I think I need to add a cross brace right in front of the bridge plate, and see how that levels out the top. I can then test it for a while and easily carve it down some with a small plane thru the sound hole if it's too stiff. What do you think?


Now on to some more forward progress!







These are some shots of the x braced Ditson, and so far so good. So far the bridge is holding good, and it plays well and sounds good. I need to play it a few days and let it settle in, get the ladder braced one's problems fixed and then I can start evaluating.

So, two steps forward and one step back, but it's moving in the right direction anyhow!
Joe

[Dennis Leahy]

Joe,

Nice job on the R&R of the bridge, and a special tip of the hat to you for showing it. I can't say it enough - we all learn 10 times more watching problems get discovered, analyzed, and repaired than a "perfect" build (such as any book on guitarmaking.)

Can't wait to hear them sing. Let us know your initial thoughts.

Dennis

[Eben]

Coupla comments and thoughts, Joe:

Especially with a bridge lifting like that one was, you don't even need heat - I've always followed Hideo Kamimoto's methodology of using a think knife and working it slowly without anything else - 9 times out of 10, I can get a bridge cleanly off just taking my time and doing that. If one meets significant resistance, then stop and apply heat...

For your top deflection situation, if ever there was a better case for a JLD Bridge Doctor, this is it
http://www.stewmac.com/shop/Tools/Speci ... octor.html
in fact, with your designs, I'd recommend you buy one and then look at 'em closely, and knowing you, I'd bet that would take care of future issues, (Nod, nod, nudge nudge, wink wink...)

E

[Joe Sustaire]

Okay Eben, here we go...I installed a bridge doctor and and re-profiled the bridge and glued it and let it cure for a couple of days. It seems like a good job this time. And the bridge doctor took care of the deforming top. Problem is, now I'm not comparing ladder bracing to x bracing. Now I'm comparing ladder bracing with a bridge doctor to x bracing. So much for my comparative analysis.

Worse, while it sounded good, it didn't seem to sound exceptional like I remembered it sounding before I noticed the bellying and the bridge lifting. The trebles especially seemed subdued. So, I loosened the strings and backed off the adjustment of the B.Doc. and tuned her up again. A little better, but okay sound, not exceptional. Very even sound, but kind of flat, like when in recording you dial in too much compression.

So in the interest of sound, and testing my memory, I took the B.D. off. Incredible sound, it just sparkles, loud, warm, and alive. That was another thing, with the B.D. on, it didn't vibrate as much, now it just resonates from end to end, very definitely alive.

Here's a couple of pics,





Now it's hard to see in the photos, but it does have some sinking between the bridge and soundhole, not horrible but definitely there. I also pm'd Nehemiah Covey, one of our fairly new members and asked his advice since I recalled he had built some parlors and might have experience with ladder bracing. He reviewed my thread and sent me a nice long pm with suggestions and helpful tips. Thank you Nick!

Nick suggested x lite strings for one, and adding some light bracing lengthwise, between the two crossbraces in the lower bout too stiffen the top. I've got light strings, 12 to 52, on now and will try the x lights when I can get some. For now I usually de-tune 1/2 step, so I went ahead and de-tuned both guitars down a full step to ease the tension a bit.

I've heard it said that the best sound comes right when the guitar is teetering on the edge of implosion. I don't know, I hope I'm not quite that close, but I tell you the guitar sounds great!!! The x brace sounds good, loud and well balanced and I'm very pleased with it also. But the ladder, sounds a little warmer and looser. Alive. I was playing back and forth trying to test them and asked Patty to listen and pick which sounded better to her. She didn't know which was x or ladder, she picked the ladder braced as the best sounding, both sounded good but she liked the ladder better.





So there they are. The ladder braced is on the right with rosewood binding and headplate. I think for now I will closely monitor the top and see how it goes. Maybe a little bellying is the norm on these, I know the old one's I have bought all suffered from it, but maybe the under bracing is the key to their wonderful punchy sound. If it starts to get worse I will go back and add some remedial bracing, but for now I'm just going to enjoy the singing!

Joe

[Chris aka Sniggly]

TWINS!.........You know all twins are different in some small way.

Way to go Joe....I love it. Wish I could play them honkers.....

Chris