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| Double Sides Info Please http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=10282 |
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| Author: | Dave White [ Wed Jan 10, 2007 12:32 am ] |
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Hesh, Tim McKnight did this pictorial on the APM Forum. |
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| Author: | Serge Poirier [ Wed Jan 10, 2007 1:09 am ] |
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Hesh not an expert but my first sides were a thin cedar ply and i'm guessing that the sandwiching helps for the bending for they came out of my bender perfect although steam bending must have played a role. I'll let the others give you more pertinent answers though, i think Peter M is the one that did just this recently. 
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| Author: | Colin S [ Wed Jan 10, 2007 1:10 am ] |
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Howard Klepper laminates his sides, the only reference I can remember here was regarding the cascamite glue he uses to glue the laminations together. I'd go have a look at his site as he does deatil a lot of his building ideas. This was the thread Hesh, cascamite Colin |
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| Author: | Alain Desforges [ Wed Jan 10, 2007 2:45 am ] |
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I've always wondered why not leave the sides thicker to begin with? My last two have been in the .120-.125 range. Venetian and Florentine cutaway. I didn't have any problems bending either one. True it was EIR... Am I missing something? |
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| Author: | JJ Donohue [ Wed Jan 10, 2007 3:14 am ] |
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Another factor I believe are the liners. I recently used Paul Woolson's solid liners and it made a significant difference in the side stiffness. These liners are similar to those described by Ervin in his video. By using stiff liners and thinner sides you get the benefit of light, yet stiff construction. Perhaps Paul can chime in on the liner issue. |
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| Author: | peterm [ Wed Jan 10, 2007 4:08 am ] |
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Tim McKnight has done some and there are many benefits to the guitar.... Tim? time to chime in! 
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| Author: | Pwoolson [ Wed Jan 10, 2007 4:26 am ] |
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One of the advantages is that you can have two very thin pieces glued together that are stronger than one piece of the same thickness. I don't do it because for me, the look of a different type of wood on the inside of the guitar than the outside (or even different grain pattern of the same wood type) is distracting. Tim's the man for this. JJ, I'm not sure what I could add to your post. You pretty much said it. The stiff linings (and mine are extremely stiff) allow for thin sides while still being structurally superior to thicker sides with standard linings. They take 7 times the work (in number of steps to make them) to make but they are worth it to me. That's how structural they are. |
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| Author: | JJ Donohue [ Wed Jan 10, 2007 4:34 am ] |
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Paul...are you planning to offer the liners for sale again next time to subject yourself to the ordeal? I'd definitely be interested. I looked into making my own but decided it was a PITA for the few that I require. 
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| Author: | Tim McKnight [ Wed Jan 10, 2007 4:36 am ] |
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1) What is the glue that is used to laminate the sides? TAP ADHESIVE, "SUPER HARD" IS THE NAME OF IT. 4:1 RATIO MIXED BY WEIGHT NOT VOLUME. YOU CAN ALSO USE WEST SYSTEM EPOXY. 2) What thicknesses are the two sides that are laminated together? FINAL THICKNESS SHOULD BE AROUND .100". MY OUTER SIDE IS THICKER THAN THE INNER. 3) How is the clamping done? MANAY WAYS TO DO IT BUT THE PICTORIAL SHOWS MY METHOD. 4) I assume that they are laminated prior to bending if true does the bending experience in a Fox style bender change when bending a laminated side? NO, AFTER BENDING. 5) Does any one use two different kinds of woods in a single laminated side? YES, BUT THEY SHOULD BE A "TONEWOOD" OF AN APPROXIMATE COLOR MATCH TO THE EXTERIOR. 6) If epoxy is the glue it must be harder on tools like the router bit and plane blades used to profile the side. True? NO 7) Anything else that you care to share? SOMEONE ASKED WHY NOT USE A THICKER SIDE TO BEGIN WITH. BY DOUBLING YOUR SIDES YOU VIRTUALLY ELIMINATE THE CHANCES OF THE WOOD CRACKING FROM AN IMPACT. YOU ALSO ELIMINATE OR GREATLY REDUCE ANY WOOD MOVEMENT DURING SEASONAL CHANGES. PLEASE DON'T USE THE WORD "LAMINATE" AS THAT HAS A NEGATIVE CONNOTATION AND LIKENS YOUR GUITAR TO A THIRD WORLD IMPORT. I PERSONALLY PREFER TO USE THE TERM "DOUBLE" OR "MULTI" SIDES AS THIS DIFFERENTIATES YOUR HIGHER QUALITY PRODUCT FROM THE LOWER END INSTRUMENTS. Comprende? Not trying to yell with my responses guys, only trying to use caps to make the responses stand out. It is a LOT of extra work to build with double sides and more material and labor cost but the benefits are worth the work IMHO. Hope this helps. |
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| Author: | Don Williams [ Wed Jan 10, 2007 4:53 am ] |
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Once again, I can't view the pictures in Tim's post on the other forum. Rats. It would seem to me that it would be easier to thickness sand the two pieces to a given thickness, then laminate them on a single mold using vacuum as is done with veneering. That wouldn't take all that much time I would think... Also, (and no offense) I can't see where the bindings that Paul makes are going to be any more stiff than the reversed kerf linings, unless perhaps they're substantially thicker or taller. If not, once the reversed-kerf linings have been glued to the sides, they are structurally pretty much the same. |
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| Author: | Pwoolson [ Wed Jan 10, 2007 4:56 am ] |
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Don, no offense taken. The difference is the same as a double side being different from a single side. Two pieces of wood being sandwiched together will always be stiffer and stronger than one. |
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| Author: | LanceK [ Wed Jan 10, 2007 5:09 am ] |
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Don, I am using Pauls liners on my current batch, they are, In my best Bevis and Butt head eh,heh,heh There, eh,heh,heh Stiff!
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| Author: | Steve Saville [ Wed Jan 10, 2007 6:15 am ] |
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[QUOTE=Don Williams] Once again, I can't view the pictures in Tim's post on the other forum. Rats. [/QUOTE] Don, This is a copy of Tim's post on the other forum. I hope you can see the pictures now. [QUOTE=Tim McKnight] I have recently switched over to building "Double Sides" on my guitars. It is a lamination process but since the word "lamination" is associated with cheaper guitars I prefer to call them double sides. Why double sides, you may ask? Certainly NOT because it is any easier. Quite the contrary, it is a royal pain in the .... rear. Double sides have many advantages over single sides: They are EXTREMELY rigid, are virtually crack proof, they will not move around under humidiy or temperature changes and they provide a much stiffer and more stable rimset to support the top, back and neck. They are about the same thickness as a one piece side set and only slightly heavier due to the added weight of less than 3/4 of a liquid ounce of structural epoxy resin. There may or may not be a tonal advantage. I don't have enough of them in the field yet to tell. However, just tapping on the rimset, it will ring just as loud and with as much sustain as a solid one piece side set. Maybe even slightly more so in both respects. Why go to all of the extra work? Well, I am always looking for a way to improve each and every guitar that I build. I truly believe this design has many advantages over a single thickness side set that it warrants the extra work on my part for the behalf of my customers. Since I put soundports in the majority of my guitars the double sides will also eliminate any structural or cracking issues that could arrise due to unplanned impacts or abuse. A thin inner side and a thicker outer side are bent at the same time in my Fox style bender. The tools that I use are a solid inner bending form of the final shape body I plan to build, 18 C-clamps, two strips of wax paper an outer clamping caul and 3/4 ounce of liquid two part epoxy "super hard" resin. 
The resin is squeegied onto the outer surface of the inner side (Honduran Mahogany in this case) and the inner surface of the outer side (Quartersawn Curly White Oak). Say that 10 times really fast. 
Both inner and outer sides now have an equal amount of resin applied and are ready to be joined. 
First a strip of wax paper goes down so the side set will release from the form then onto the form the double sides go. 
Another strip of wax paper goes on top of the outer double side and then the outer clamping caul goes on. Two clamps are snugged up at the waist to hold the side set together while I line up the ends. The resin is pretty messy and slippery and the side halves try to skid around under the clamping force. 
The remainder of the clamps go on while keeping a close eye that the sides remain perfectly aligned as gradual clamping force is applied. Excess resin begins to ooze out so I have to wear rubber gloves and put plenty of newspaper down to contain the mess. 
24 Hours later the resin is rock hard and the side set is removed from the form. You can see how the resin was forced through the wood pores on the inner side set. 
Even the exterior side set shows signs of resin permeation. This sands off and does not effect the final finish process. 
As you can see the Double Side set now holds its shape perfectly and there is absolutely no tension in the side set. We [luthiers] all aim to build our guitars with little or no tension in the wood so there are not any undue stresses placed on any joint of the guitar. 
Here the finished double side side set rests perfectly in the side form with no signs of springback or twisting. These completed side sets are a joy to work with. They are so stiff and not the least bit fragile like the floppy side sets I was acustomed to working with previously. 
This pictorial is by no means meant as a slam or to degrade other luthiers work. This is just a new way that I have found that works well for me. There are several luthiers who are using this method so it is not something new that I have invented or that is revolutionary. Ervin Somogyi, Michael Bashkin, Michi Matsuda, Mario Beaureguard and many others have found this process successfull for them. It is just a path that I have chosen to pursue and to see where it leads me next.[/QUOTE] |
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| Author: | russ [ Wed Jan 10, 2007 7:57 am ] |
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Hesh, Another take on the "double side" is the one that (I think!) Sheldon Schwartz is using on his latest model. Basically, it is a 2 walled construction, consisting of the outer side, then the linings (solid linings, I would presume), then an inner wall, so a section through the side would look similar to this:  with an air gap between the walls. Should make for a very rigid side as well. It's an interesting take on things that I might try someday. Good Luck! |
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| Author: | Don Williams [ Wed Jan 10, 2007 8:21 am ] |
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Steve, thanks a lot, I really appreciate the effort. Unfortunately, something here at work in our firewall is blocking certain images. Life goes on... |
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| Author: | burbank [ Wed Jan 10, 2007 8:27 am ] |
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Tim, Thanks for the tutorial! I can see how stiff sides would reduce energy losses, but -- as a newbie, mind you -- I wonder if some amount of sound production through the side is lost from using an air gap. On a conventional side, I can hear a lot with my ear against a side. Would the air gap act as a sound insulator? |
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| Author: | Tim McKnight [ Wed Jan 10, 2007 8:33 am ] |
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The "hollow" side set is extremely stiff as well becuase it is a structural box beam. Another benefit is the inner side is free to vibrate without being dampened by the person holding it and could possibly add to the tone of the instrument??? Another benfit is there is no need for linings and it provides a very clean look on the interior. The biggest drawback IMHO is the difficulty of making a repair should the outer side develop a crack or hole. Just think abbout it for a while... It's possible to make the repair but it will not be as clean as if you had access to both sides of the wood. |
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| Author: | Serge Poirier [ Wed Jan 10, 2007 8:39 am ] |
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I'm wondering here, if the goal is to obtain a rim that is very stiff and acting like drum, why not just glue more side braces that would be tucked in the linings or why not do it a la Dave White's with his long bars that are attached to the sides and his neck block? |
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| Author: | KenMcKay [ Wed Jan 10, 2007 8:51 am ] |
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[QUOTE=Pwoolson] Don, no offense taken. The difference is the same as a double side being different from a single side. Two pieces of wood being sandwiched together will always be stiffer and stronger than one. [/ QUOTE] Is this true? If you take a bookmatch pair of side wood and slice one in half then glue it back together and compare to the other side of the bookmatch (planed slightly to account for kerf loss) for MOE they would be the same I think. The glued one would be heavier, slightly, because of the glue. If you make your layups from different woods or same wood but different grain orientation the stability of the side does improve. I use a vacuum bag external to the mold and get the job done pretty easily. I can't seem to post photos last time I tried. |
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| Author: | Steve Saville [ Wed Jan 10, 2007 9:17 am ] |
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Veneers are pretty easy to work with. I'm wondering if a "normal" outer rim that is about .080" think with a veneer of about .040" would do the trick. Also, having made a number of RC airplanes with foam wing cores with 1/64 Baltic birch plywood, I can tell you for sure that it can add a lot of strength. That stuff has three layers. Instead of a double side, you could call it a quadruple side! 
I used contact cement for that and it worked great. I wonder if contact cement would be good for this application also. |
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| Author: | burbank [ Wed Jan 10, 2007 9:17 am ] |
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[QUOTE=Tim McKnight] The "hollow" side set is extremely stiff as well becuase it is a structural box beam. Another benefit is the inner side is free to vibrate without being dampened by the person holding it and could possibly add to the tone of the instrument??? Another benfit is there is no need for linings and it provides a very clean look on the interior. The biggest drawback IMHO is the difficulty of making a repair should the outer side develop a crack or hole. Just think abbout it for a while... It's possible to make the repair but it will not be as clean as if you had access to both sides of the wood.[/QUOTE] Wow. No linings. That's a big plus. Thanks for the clarification, Tim. |
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| Author: | CarltonM [ Wed Jan 10, 2007 2:34 pm ] |
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[QUOTE=KenMcKay] If you take a bookmatch pair of side wood and slice one in half then glue it back together and compare to the other side of the bookmatch (planed slightly to account for kerf loss) for MOE they would be the same I think. [/QUOTE] I think there would be a difference. It seems to me that the glue layer acts as a reinforcement, like the fiber in fiberglass or rebar in concrete. A thin layer of quality epoxy is very glass-like. It doesn't want to bend. It can break, like glass, but the wood on either side of it acts to prevent that. It's a symbiotic relationship. |
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