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| Side braces, are they needed? http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=3235 |
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| Author: | Josh H [ Thu Sep 15, 2005 11:53 pm ] |
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Just looking to get some opinion on side braces. The main question I have is, how necessary are they? My thoughts to this point have been that with woods which seem less stable I will brace the sides. But if the wood is stable I don’t always worry about it. Josh |
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| Author: | L. Presnall [ Fri Sep 16, 2005 12:10 am ] |
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Josh, I've not used them yet...I'm on guitar # 10 and thought sure I'd need them on this one, since the sides are quite thin...but they came out of the bender flat and true, and I didn't use them this time either...I'm sure many will chime in here and they're much wiser than I so I'm looking forward to reading what they have to say! 
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| Author: | Brock Poling [ Fri Sep 16, 2005 12:21 am ] |
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If you get a crack in the side (maybe some one drops the guitar...) they will help contain the crack. I see no reason why you WOULDN'T put them in. They weigh virtually nothing. just my .02 worth. |
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| Author: | stan thomison [ Fri Sep 16, 2005 12:25 am ] |
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They are not an absolute, but I would (shop does on all) put them on for stability and as noted to contain any crack that may happen in certain areas. Why not put them on as they don't add any appreciable weight or voicing problems |
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| Author: | Josh H [ Fri Sep 16, 2005 12:40 am ] |
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Good point guys. That is the way I have been starting to feel. It doesn't hurt anything to have them is the way I am starting to look at it. Any thoughts on the shape of the brace? I can't see it making that much of a difference. Josh |
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| Author: | arvey [ Fri Sep 16, 2005 1:24 am ] |
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I didn't on my first guitar but all since. Second guitar had a few side braces and it was Dropped. Crack went right up to the brace and stopped there. I now put even more braces on. |
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| Author: | Michael McBroom [ Fri Sep 16, 2005 2:25 am ] |
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Josh, You asked about brace shape. I've seen some braces made from soundboard offcuts, about 3/4" wide by 1/8" thick or so. However, on my classicals, I go for more of a traditional shape. Here's a pic of the inside of my last build: 
Best, Michael |
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| Author: | tl507362 [ Fri Sep 16, 2005 2:54 am ] |
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This is an interesting topic that I got very good advice from Edward Victor Dick of Victor guitars. He was inspecting my 2nd guitar which is an Olson SJ copy. As he was looking around through the sound hole he makes a statement that he was glad to see that I put tall side braces on. When I asked him why, his statement was that he likes to see stiffer braces on bigger bodied guitars. In my case my butt end was 4 7/8" which is a thick bodied guitar. He said with it being thick body and 16" lower bout, the guitar will tend to distort under all that pressure. The side braces will tend to stiffen the sides and let the top and back pump. I think I saw on Kathy Matsushita's site where she uses popsicle sticks for side braces. This is all theory, so I don't know for sure. I'm just passing on what I heard. Tracy |
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| Author: | CarltonM [ Fri Sep 16, 2005 3:13 am ] |
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As well as bumps and drops, low humidity can crack the sides of an improperly maintained guitar. Remember, they're made of very thin, possibly brittle, hardwood. Best to give 'em some support. FYI, I've heard and read from the experts that the first and best place to put side braces is any section that straightens out; e.g. the flat-ish transition between the big curve of the lower bout and the waist (and the upper bout and waist). As in any construction, arches are strong, flats are weak. As for material, people have used anything from linen strips to chunks of hardwood. I'd suggest using the same stock that's bracing your top--it's light and strong. |
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| Author: | csullivan [ Fri Sep 16, 2005 3:18 am ] |
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On my steel strings I might put a side brace across the flat area just below the waist, but not always. What I will always use now is strips of cloth, called selvage (sp?), I think. It's about 1" wide. You can buy it at any sewing goods store. The threads in the material run at 45°. It's actual use is to wrap around the edge of a piece of material. You can glue the strips right off the edge top and bottom and glue your linings right over them. I'll place them every 3 or 4" around the perimeter. They add virtually no weight but add surprising strength. You can also use the material to cap the intersection of X braces. Alan Carruth tells an incredible story about guitars and a plane crash. I don't remember the details, but the only part of the guitars that weren't completely smashed were the sides that were reinforced as described above. Craig |
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| Author: | arvey [ Fri Sep 16, 2005 3:55 am ] |
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I have used both wood and cloth glued on with hide glue. HEre are pics of each Wood 
cloth 
Both seem to work equally well. |
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| Author: | Josh H [ Fri Sep 16, 2005 4:28 am ] |
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Thanks for all the great info guys! And thanks for taking the effort to post some pictures. I just like to see the insides of some other people’s guitars. I am just heading out to my shop to glue the liners for the back (did the top this morning). I think I will go with some wood side braces on this one, but I like the looks of the cloth. Perhaps I will give that a try in the future. Josh |
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| Author: | arvey [ Fri Sep 16, 2005 5:00 am ] |
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I believe it was allen who did some testing on the beenifits of side bracing as well as types of glue to use in it. If I recall correctly it increased resistance to cracks qiuite a lot but he also found that hide glue was the way to go. |
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| Author: | Dave-SKG [ Fri Sep 16, 2005 5:10 am ] |
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For what it's worth I think the damage to this guitar would have been catastrophic if not for side bracing. This realy was a simply repair... and you can barely tell a huge Hunter Ceiling fan had it way with her!  
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| Author: | Arnt Rian [ Fri Sep 16, 2005 5:50 am ] |
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Ouch, Dave! But what were you doing with the guitar up in the air like that  ?!
I use mahogany side braces because it looks OK with the mahogany linings. I extend the side braces almost all the way between the edges of the sides and glue two lining pieces (what are they called, the sections between the kerfs?) over them. It's the way Benedetto shows it in his book. The idea behind the braces not going all the way to the side's edges is that if the sides shrink the braces could push the plates out. That would also mean that the glue bond between the brace and side would have to slip first, so I'm not sure I should worry about it. Anyway, the main reason for doing it this way is to avoid a possible stress riser (?), a weak spot between the brace and the lining which can in itself lead to a crack in this area. Sorry about the poor picture quality, here's a snapshot: 
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| Author: | Don Williams [ Fri Sep 16, 2005 5:59 am ] |
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Craig, the plane crash in question was the mail delivery plane that was shipping Mark Blanchard's guitars home to him after the Newport show last year. The only thing the held in place was the mechanicl neck joint and the side tapes. Tragic story though. Arnt, your picture is just fine...nothing poor quality about it...and the guitar looks exceptional. Your work continues to impress! Michael, that's some cool bracing on that classical! I've often thought about using bracin that was curved like that on acoustics. |
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| Author: | Kevin Gallagher [ Fri Sep 16, 2005 6:00 am ] |
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Bent quarterawn wood has its least strength against flexing and cracking in the areas that exhibit the least amount of bend. In a dreadnaught, the most critical areas to brace acorss the sides are those that are above and below the waist bend and before the bends that lead to the butt wedge and the neck joint, Just apply a minimal amount of pressure with your thumb on the side of any Dread in those areas and you'll see that it's true by the flexing that occurs. The braces outside opf these areas will provid the crack containment as they prevent the side from cracking beyond tham, but the ones in these flat areas actually provide protection from cracking itself by preventing flexibility that can allow them to occur. I use the Dreadnaught shpae as an example because of its obvious flatter areas where the cracking can occur more readily, but any guitar has these areas which are less rigid and more prone to cracking cause by flexing under pressure or impact. Just some though when you're dciding whether or not to place those side braces according to where they're most practically needed or where they look the coolest and most symmetrical inside the guitar. Regards, Kevin Gallagher/Omega Guitars |
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| Author: | Tim McKnight [ Fri Sep 16, 2005 6:58 am ] |
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I have used wood and cloth and now I use cloth "Bias Hem Tape" from the fabric store. Open the package and iron the cloth tape (it's not adhesive backed) so that it is completely flat. Paint a stripe of glue (hide, TB or my choice > LMI white glue) on the side and lay the cloth tape over the glue and take the end of the brush and dab it to force it flat into the glue. Wipe off the excess glue with a damp cloth. After two days sand the cloth lightly to remove any nubs. Now glue your linings right over the tape and then paint the exterior exposed glue surface of the tape with Shellac. The Shellac will prevent the glue from degrading from oxygen exposure over time. If using wood strips they need to run the full width of the sides other wise you will form a stress risor at the point where the wood strips and linings meet. If bumped this can propagate a crack that will continue and be unable to stop because there is no support in that area. |
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| Author: | Alan Carruth [ Fri Sep 16, 2005 7:08 am ] |
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Ah, the answer to this one hinges on the question of what you mean by 'need'. :) I've used side tapes for years to limit the spread of cracks. I tested out cotton-poly bias tapes and nylon a few years ago, to see which was a better reinforcement on strips of side stock. I put on the tapes with either hide glue or Titebond, and measured how much force it took to break the pieces with the tapes on the tension side. The bias tapes about doubled the force it took to break a 2" long section of 2mm side stock of any of the woods I tried. Hide glue worked better: the tapes sometimes came loose with Titebond. Neither glue stuck very well to the nylon tapes, which, although strong, tended to come unglued at lower forces than were required to break the cotton-poly reinforced side samples. Wood side fillets are, of course, stronger. However, they must be inletted into the liners. If the fillet stops short of the liner then any blow to that area will have the force concentrated at the junction between the liner and the fillet, and that's where it will break. That's the hardest spot to fix.... The issue thus comes down to how strong you 'need' the sides to be, and how much time you want to put into making them stronger. IMO side tapes add an adequate amount of strength, and, more importantly, limit the damage. Any crack should stop at the next tape if it's glued down properly. (note that air attacks glue, so you can't expect old tapes to hold well unless thay are protected from the air by, say, thorough shellacing). Some builders rejoin that _no_ amount of extra strength is 'adequate', and lots of fillets are the best way to keep the top and back together when you're dealing with gigging musicians. One could, I suppose, lay in a couple of layers of carbon fiber, but how far do you want to go? So that's what I mean by 'need'. |
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| Author: | Dave White [ Fri Sep 16, 2005 7:17 am ] |
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[QUOTE=Tim McKnight] If using wood strips they need to run the full width of the sides other wise you will form a stress risor at the point where the wood strips and linings meet. If bumped this can propagate a crack that will continue and be unable to stop because there is no support in that area.[/QUOTE] Tim, I'm not sure what you mean by a "stress riser". I notch my wooden side braces into the reverse kerf linings that I use. Does this get over the problem? This is the best picture I have to illustrate - not brilliant I'm afraid. I use cedro for the side braces by the way (Spanish cedar), very light and a lovely smell: 
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| Author: | letseatpaste [ Fri Sep 16, 2005 7:38 am ] |
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I wonder if in some instances the side bracing will actually make damage more severe in an accident. If a guitar is dropped or whatever, it obviously has to absorb the impact somehow when it lands. If it begins to crack and the crack is limited to an area between side braces, is it going to cause a break instead of just a crack? It seems like a longer simple crack would be easier to repair than a short splintered break. Note the "some" in italics... |
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| Author: | Rod True [ Fri Sep 16, 2005 6:05 pm ] |
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Here is a pic from Jim Olson's site. Notice anything missing? 
So why would a guy who gets 8-12K per guitar (more in some cases) chose not to use the side braces? Time to make a phone call. |
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| Author: | Mattia Valente [ Fri Sep 16, 2005 7:07 pm ] |
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Why? Because everyone has a different rationale for doing what they do. I use 'em, because it's cheap insurance, and I'm sold on the arguments, but the vast majority of guitars out there don't have side braces. |
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| Author: | Josh H [ Sat Sep 17, 2005 12:10 am ] |
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This has been a great discussion. Im pretty much set that I am going to start using some sort of tape/cloth that is soaked in glue, like Alan and other have suggested. I see it as cheap insurance like Mattia said. For the amount of time it will take to put them in I think it is really worth it. Josh |
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| Author: | Mario [ Sat Sep 17, 2005 12:36 am ] |
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but the vast majority of guitars out there don't have side braces. The vast majority of guitars out there are also plywood, which doesn't need braces <g> A stress-riser is a weak area next to a stiff area. If we stop our brace just short of the linings, the unbraced space is at a stress riser, and any blow the side receives will be transmitted to that area(and likely cause a break). As has been said, do we NEED them? No. A guitar will sound and play like a guitar without them. But one crack, and it'll go around the guitar. I've seen a few unbraced ones, and a couple with linen strips(hide glued, too, as in mid 1940's hide glued...), cracked from neck heel, right around, through the end block, to the other side of the neck heel. You want to talk of a tough repair? I ain't risking my work that way to save 10 minute's making braces. I doubt any of you would want to, either. |
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