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ezFolk Forums > General > Instrument Repair and Luthiery > Anyone have a piece of mahogany to spare? |
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| Anyone have a piece of mahogany to spare? - Instrument Repair and Luthiery - General - ezFolk Forums | |||||||||||||||
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Philj200 Approved 
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This thread began by accident on a thread about strap pins. A few days into the thread I had a terrible accident at a jam. The strap slipped of the base pin, the guitar, a 1963 Gibsoon ES-175, crashed to a concrete floor. The line plug caved in the guitar side and it was three days before I could take a seep breath. I cannot find a luthier I trust to fix it so I will fix it myself. This is my plan: Cut away the damaged wood with a Dremel. Brace all suspicious cracks and scrathes from the inside. Add cleats to the opening to recieve a patch block. Sand and refinish with nitrocelluous. I have the tools, the space and time. I trust my skills. What I don't have is a small piece of mahogany. Ideally, it should be 1/8" by an index card. That would give me more than enough for patch and cleats. But to get that little piece of wood I have to buy an entire side section or a slab of mahogany and mill it down. In either case spending a lot of money and wasting 98% of the wood. Maybe I heard too many stories about the rain forest, but I just can't waste that much wood. Does anyone have a scrape of mahogany to sell, trade or give? As long as it's about 5x3" I can mill it thin enough. A broken guitar side? If you can help or offer advice respond here or by PM. (Gibson and StewMac have been very helpful with their advice.) Thanks, Phil
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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Philj200 Approved
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This is the damage. It is not very big. But in a difficult to reach place. Attachment: DamagetoES-175.jpg (Downloaded 74 times)
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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theBlackman Approved 
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From my point of view, I would remove the "socket" make a block of pine about 1/4 in thick shaped to fit INSIDE, with a hole for the "Pin socket" pre-drilled. When it is shaped and fitted, glue it in with HIDEGLUE, and use some thin splines as pressure pads inside. (the length of the inside width neck to bottom, plus a inch or two. Put the patch block in. Insert the "Splines" (three or four cut from any scraps :Oak, fir, apple, whatever) SPRING THEM INTO A CURVE and lock one end at the neck and the other against the block. As they try to straighten out they will act as clamps. Then go to any furniture repair shop and get a scrap of VENEER mahogany (you can get different weights, as I recall, or build them up in laminates to the thickness. Cut a patch to fit the hole. For the crazing, take hide glue and smear it into the cracks, from outside, with your fingertips and when it's dry take a damp rag with warm water and wipe the excess off. For the patch for the hole, cut a diamond shape just large enough to remove the ragged edges. Cut the edges with a beveled angle that tapers from the inside block to the outside. Use a paper/cardboard template. Cut both the "hole" and the patch you plan to fill it with from the same template. The top is where the sound is generated. A thinish pine block inside the end of the body won't damp the sound. But as the area is already stressed, a thin patch inside or cut and fitted to the damage won't have a lot of strength. Actually, now that I think about it I am pretty sure I have some mahogany. PM me with a SNAIL MAIL ADDRESS. I'll get back to you and if I do, as I think I do, I'll mail you a chunk. Dusty ADDENDA: I do have. It is cut and a starting slot for resawing made. Get me your address and I'll get it out this week. About 6 by 8 inches 3/4 aged 15 years. Last edited on Wed May 28th, 2008 11:32 pm by theBlackman ____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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Philj200 Approved
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Check your PM. I'm naming a kid after you. Might not be one of mine. Maybe one of my neighbors. Wow!!
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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Philj200 Approved
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From my point of view, I would remove the "socket" make a block of pine about 1/4 in thick shaped to fit INSIDE, with a hole for the "Pin socket" pre-drilled. --Good idea but the good folks at Gibson in 1963 let me with vrtually no slack on the cable. It is old wiring. And since it works, I intend to handle it as little as possible. I was planning on a backing it up with hard work strips. Gibson just used an extra and very thin veneer inside. I suspect it was to stop drill chatter. When it is shaped and fitted, glue it in with HIDEGLUE, and use some thin splines as pressure pads inside. (the length of the inside width neck to bottom, plus a inch or two. --Not so sure. I used hideglue when I apprentices with a (terrible) luthier in the 60's. He was famous for having things fall apart. I've had excellent experience with Titebond. Put the patch block in. Insert the "Splines" (three or four cut from any scraps :Oak, fir, apple, whatever) SPRING THEM INTO A CURVE and lock one end at the neck and the other against the block. As they try to straighten out they will act as clamps. --Intesesting idea. The hole I cut will be three inches long by less than two inches. Not sure is splines not cleats are the best idea. Do you recommend soaking the splines first? Then go to any furniture repair shop and get a scrap of VENEER mahogany (you can get different weights, as I recall, or build them up in laminates to the thickness. Cut a patch to fit the hole. --Before your reply, I had asked the StewMac people about building up veneer to the thickness I need. They did not think it would work. With the piece you described in, I'll make a final determination. There many ways to skin a cat. (Assuming cold cats are something to be desired.) For the crazing, take hide glue and smear it into the cracks, from outside, with your fingertips and when it's dry take a damp rag with warm water and wipe the excess off. --Rub pigment into the cracks along the glue? For the patch for the hole, cut a diamond shape just large enough to remove the ragged edges. Cut the edges with a beveled angle that tapers from the inside block to the outside. Use a paper/cardboard template. Cut both the "hole" and the patch you plan to fill it with from the same template. --Had bad luck with tapered cuts. They absorb a lot of glue and that glue can age differently leaving lines. Not that people spend much time looking at the connector. Did that to patches in the face of a guitar once and in a year I had rectangles and a very pissed-off owner. I intend to cut out the damage using a scribe to make straight lines. And make a template from the actualy hole. Transfer the template to the stock. Cut, install and give it umteen coats of red mahogany nitrocellulous. Pics to come as progress warrants. It's been a week and the jam is tonight. Just bringing a mike and a bag of blues harps.
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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theBlackman Approved
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The "splines" are not a permanent fitting. You need to get something to press the pieces you are gluing inside the body against the piece they are to be glued to. If you use a "batten" type thin, and flexible, when it is longer than the space you are putting it into, it tries to straighten out. The tension acts like a clamp. As a poor example. Take a narrow strip of card stock. Not corrugated board, but heavy card stock. If you put a finger on each end and force it into an arc you will feel it resisting and trying to straighten out. Imagine that same thing made of wood about 1/8 to 3/16 thick and about 3/4 inch wide. If you take a 20 inch batten of this type and put it between two walls 18 inches apart, it must curve and it will press outward against the two walls as it trys to become straight again. Unless you have some very deep clamps, or use a screwjack type of interior clamp, you need something to press the inside glued piece to the body of the guitar. For the crazing, Hideglue worked into the crack should glue the striations together. Hideglue itself is tan to dark brown. When you are done you can lightly sand the crazed varnish to smooth off the fractured edges. Then if you want you can put a little fresh varnish (or lacquer) on a rag wrapped around your fingertip, and Buff the area with the varnish/lacquer dampened rag. You can test the "varnish" with a little alcohol. If it "melts" then the instrument is SHELLACED. If you try a little mineral spirits and it gets tacky, then it's varnish. If neither of these work, then it probably is lacguer or one of the new synthetics. As the area is damaged already, if you test it with the above on the damaged area, you can wetsand it smooth when you know what it is and attempt to repolish, recoat, relacquer or whatever. As for the "Short wires", you can unsolder them at the plug. There should be (check first), enough slack for the wires to stick out of the body of the guitar. Usually 1/4 to 1/2 inch. More than enough to let you resolder the plug and refit it. Last edited on Thu May 29th, 2008 09:00 am by theBlackman ____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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Philj200 Approved
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The "splines" are not a permanent fitting. You need to get something to press the pieces you are gluing inside the body against the piece they are to be glued. --Ah, I think I get it. If you use a "batten" type thin, and flexible, when it is longer than the space you are putting it into, it tries to straighten out. The tension acts like a clamp. --That's why I asked about wetting. Unless you have some very deep clamps, or use a screwjack type of interior clamp, you need something to press the inside glued piece to the body of the guitar. --I don't have those clamps. StewMac sells them. I was envisioing glueing strips of hardwood, about half inch wide by an inch wide than the removed rectangle. So they overlap the edges by a half inch top and bottom. This can be glues by spring or small C-clamp from the outside. When dry, the patch block can be glued over the strips. I have a clamp on order that is made for holding side patches in place. For the crazing, Hideglue worked into the crack should glue the striations together. --Only one crazing is an actual crack. But seems stable. I plan to put a cleat or two inside once the rectangle is removed and I have some access. There is very little wiggle room in this critter. Hideglue itself is tan to dark brown... --This is a version of French polisihing isn't it? You can test the "varnish" with a little alcohol. If it "melts" then the instrument is SHELLACED. If you try a little mineral spirits and it gets tacky, then it's varnish. If neither of these work, then it probably is lacguer or one of the new synthetics. --Gibson used nitrocellulose. In the communications I've had with them, they never mention shellac. Shellac is hard to find these days. I remember buying flakes that had to be mixed with denatured alcohol to use. But while easy to handle, it was not very durable. Not a good choice for a working guitar. As for the "Short wires", you can unsolder them at the plug... --This would be a problem. There is a bulky cylinder just inside of the connector. I've never seen anything like it. And very little slack. To remove this cylinder might be a roll of the dice I can avoid. Also, it would mean making the hole must larger than the wood damage requires. I have an old quarter-incl plug for a system long in the landfill that I intend to connect and use as both a means to keep the connection from falling into the body when the wood is removed and to seal the connector when I refinish. I appreciate the wise counsel.
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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Philj200 Approved
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From an e-mail from StewMac... "Titebond is far easier to work with and in this case, probably the better choice, in my opinion. Ground Hide glue requires a more attention and more equipment such as an electric glue pot, although it is available in a liquid form for smaller repairs. You might ask your friend why he thinks you should use hide glue. You should use grain filler to fill the pores and scratches found in Mahogany, as outlined in the Finishing Schedule. I had sent you a link about that in an earlier correspondence."
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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theBlackman Approved
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Your wood is in the mail. Expect it in three to five days. Good luck. PS: rethink the "Rectangle". A diamond shape backed by a retangular patch inside will work. Unless you use 4 strips for backing retangular patchs are a bitch. So fit the patch. Put a piece of veneer glued inside. Put the patch into the hole, which is now backed by the veneer, and glue it in. Make it slightly "proud" (a little thicker), and sand to the finish surface. If you sand when the glue is slightly damp, the sawdust will fill any minor irregularities. Or cut the hole with a taper from outside to inside, and cut the patch with the same taper (top to bottom - outer surface to inner), then sand down to match the final surface after it is glued in. If stew prefers Titebond, you can go with that. I already said why I prefer Hide. It is not that hard to work with. The bottles can be warmed in a saucepan of hot water to make them more flowable. But he's the pro, so I'll defer to his judgement. But undoing mistakes is easier with the HIDE. Dusty Last edited on Fri May 30th, 2008 12:27 am by theBlackman ____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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Philj200 Approved
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theBlackman wrote: Your wood is in the mail. Expect it in three to five days. Good luck. --With on-line friends like you, you've made my luck. I am truly greatful for the wood and the advice.
If you sand when the glue is slightly damp, the sawdust will fill any minor irregularities. But undoing mistakes is easier with the HIDE. At the jam session, where the damage occured, one the regulars brought an acoustic-electric for me to play, knowing that my one electric was laid up. Nice to know good people.
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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theBlackman Approved
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You GLUE the patch to the inside backing strips or "plate". When the glue is about half dry sand the piece to surface level, or nearly so. The sawdust will mix with the glue and fill minor irregularities in the "Seam" where the edges of the patch are. The angle is not critical in thin stock, but needs to be close. If you want to check for accuracy, rub a pencil on the edges of the patch. Fit it to the hole, remove it. The "High" spots on the hole will show where the lead touched. They just trim either piece a little to fit. Then just clean off the scrapings and glue and fit the patch. From the looks of your "socket", if you remove the nut and washer, you should be able to reach in from the back (inside the body) and move the assembly to the side to have working area. And if you use a patch of veneer backing with the insert from the outside, there should still be enough socket body thread to replace the nut when the new piece is finished. You just need to have the holes for mounting pre-drilled and ready. Attachment: Repair patch.GIF (Downloaded 54 times) Last edited on Fri May 30th, 2008 08:58 pm by theBlackman ____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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theBlackman Approved
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Something like this should work. And a strip of veneer glued inside (curved slightly to fit), allowed to set then patched. If you remove the fitting for the cord (the socket), and tie it out of the way. Then mark the cut pattern on the outside (mix eggwhite with water about 1/2 and 1/2. Paint the mixture on the outside and let dry, you will get a white coating you can draw on with a pencil for layout). Then use your dremel at a slight angle to cut the damage out. If you make a template and use that to draw the layout, then use it to make the patch, and angle all the cuts, it should be easy. I would probably use a hobby knife to trim the damage but then that's me. As for the crack you mark as "stable", a 1/16 or less hole drilled at the very end of the crack will stop it permanently. Then a sliver of mahogany glued in as a plug will disquise the hole. If you don't glue and stop the crack, the vibration of use over time might, the operative is might, make it continue to run. But a small hole (round) will relieve the stress and prevent it continuing. This is a common practice for stopping cracks in metal and thin wood under stress. Attachment: DamagetoES-175.jpg (Downloaded 53 times) Last edited on Fri May 30th, 2008 09:45 pm by theBlackman ____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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Philj200 Approved
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All good advice... again. I wonder about the diamond shape around the connector, The side of the guitar is substantially curved. I'm not sure I can get the geometry right. Or would this be rubber-sheet geometry... I forgot the actual name for that field of math. Topology? Hide glue, grain filler, stain and lacquer on order. Clamps, Dremel with a new, sharp saw blade on hand. Speaking of small holes: I read about a technique for placing cleats in hard to reach places. Drill a small hole in a crack, insert a strong thin but strong thread through the hole with enough slack to grab it from the inside via the f-hole or round hole. Drill another hole in a cleat. Run the thread through the hole in the cleat and knot it securely. Coat the thread side of the cleat with glue and pull the string from the outside of the guitar. This method will brace a hard to reach crack. And even bring two pieces level. Once the cleat is dry, nip the thread, fill the hole. Hardly visible. On a dark guitar, invisible. Funny thing about that technique; I learned it 30 years ago for patching wallboard.
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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theBlackman Approved
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The curve is easy to handle. With your skills (your mention of woodworking leads me to that), lay the guitar on a piece of stiff card (a cereal box or a packing box for apliances), again not corrugated, draw the curve. Cut out a template, then lay it on your workbench or a piece of 1/2 ply, trace the outline. Then put some 3" finish nails spaced about 2" apart driven in just inside the curve, (you want it a little tighter than the curve.) Make this line of nails a little longer than the length of your intended inside backing strip. Cut a strip of thin stock (veneer), and wrap it in a towel. Pour boiling water on it. Let it sit for a minute or two. Unwrap it and press it against the nails (inside the curve), use a couple more nails to hold it to the form of nails and curve. Let dry overnight. Trim to size, and glue it inside the guitar backing the damaged area. You can remove your damage first and then glue in the backer. I would do it a little differently, but even though I could tell you how, it takes a little practice to not mess it up. Once the backing strip is glued in, and dried for a couple of days, fit the patch, and finish the project at your leisure. The reason you taper the edges of your hole and the patch is so that any error in making the cut is cancelled out by the taper fit. An exact 90 degree (which is hard enough on a perfectly set tablesaw), on all four sides of a rectangular hole and a patch to fit, plus sizing it exactly is nearly impossible. The taper on the hole and on the patch will allow them to fit together with a lot of "slop" room that won't show on the finished piece, unless you greatly mis-size the hole or the patch. You can curve the patch the same way. Only this time cut the patch, then bend it around the OUTSIDE of the nails. Yeah that use a string/wire is an old handymans trick. I've used it many times, in fact, with the diamond shaped hole, you could put the entire backing strip through the diamond, pull it tight with the string through the "socket" hole, brace it from inside and let it dry, then fit the patch. Think about the sizes of Diamond to rectangular backing and you'll see what I mean, although a hand through the sound hole to fit the patch is the best way. Last edited on Sat May 31st, 2008 03:11 am by theBlackman ____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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Philj200 Approved
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I had planned to use the guitar as a template. But I was then going to route the curve into two pieces of scrap. Making a top and bottom guide. My thinking was that I could get the exact shape. More upfront work than making a nail jig, but more accurate. I'll go back and forth a few more times. Depending on the hadrness of the wood, I intend to scribe the patch as accurately and deepliy as I can before dutting on my small-toothed bandsaw. I've achieve very accurate cuts this way for furniture repair. My table saw is no way accurate enough for work like this. Might as well use a chain saw. (No I won't.)
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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theBlackman Approved
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Whatever you use for a former to bend the shape, it will need to be a little tighter than the exact curve, unless you are laminating layers to fit a curve. The glued laminates will hold the shape. Single layers bent around a former template tend to relax slightly. After the wood has bent to shape, the curve will relax. The dried finished curve will be a lesser curve than the form you bent it around. It will be close, but the stresses are pretty much guaranteed to relax and be slightly off the true shape. For the inside curve use the outside of your "former", for the outside curve use the inside of your former. That should make the fit better as the steam/heat bent pieces nearly always relax by flattening the curve as they try to straighten out. As for "graving" the wood, I use the same method, but would probably do the entire cut with a hobby knife (Exacto or such).
____________________ Let each day start as a blank page for life to write upon. http://ezfolk.com/audio/dusty http://cdbaby.com/all/theblackman http://youtube.com/DustinFLeer |
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Philj200 Approved
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I intend to make the bending jig at a greater angle than the actual curve of the guitar shoulder. And I rethought the routed thing. Too much work and on reflection nails will give stablity to the entire patch surface. StewMac has a nifty crack spreader. This device is held like a pen. You trace the crack with the tool. It widens and deepens it to accept a spline. They want far too much for my needs. If I was doing regular luthier work, it would be something useful to have. It is useful. But not for the price. I have a 60-T (7-1/2") blade on a small power mitre saw. That might come into play for shaping the patch. The sides of ES175 is 1/8th" mahogany. Cutting through that with an Exacto blade or 15 of them is an invitation slips, scatches and frustration. I'll score the perimeter of the area to be removed but take out the wood with a Dremel rotary saw blade. Next step: Make the bending jig. Wait for packages to arrive. The next project after this is successfully complete is to rebuild an old f-hole, install a single pickup and use that for amped-jams. The ES175 will go into semiretirement. I did the same semi-retirement thing when my '49 J200 was aging faster than the calendar in the open mike rotation. I use a Martin DMX for gigs and accoustic jams.
____________________ My MP3 Section: http://ezfolk.com/audio/bands/1143/ My Myspace area: http://myspace.com/philj200 |
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