Members kwakatak Posted July 1, 2011 Author Members Share Posted July 1, 2011 I forgot to mention in the other thread where I'm destroying the guitar that survived 20 years with me that my build is progressing too. Nothing too drastic, just working on the sides. I've been advised to concentrate on getting the rims ready before concentrating on bracing the top. First step is getting the blocks put on the sides but I had to undo my boo boo with the neck block. I did some homework with a piece of Birch plywood so it was just a matter of taking a chisel to get the old piece off and reglue the new one on top of the neck block. I didn't use the go bar deck this time, just a couple of clamps after the Titebond took hold. My tail block is also birch plywood and I used a table sander to curve the back of it to comform to the curve of the side. THen I glued the tail block on and moved on to destroying my Tak. Next time the neck block goes on and hopefully the kerfing on the topside rim. Link to comment Share on other sites More sharing options...
Members rickoshea Posted July 1, 2011 Members Share Posted July 1, 2011 the bracework looks great Neil .. thats exactly what Gary had me do with my first .. splay the X's out into more of a right angle. I've no idea what effect it had on the tone as I've nothing to compare it to but I would imagine that it would let the lower bout deflect a tad more. I also finished them short of the purfling, I think it was 2mms short and the final scallop starting 5cms from the closet point of the side - again, that was all about letting the soundboard be more free to vibrate. Good stuff Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 3, 2011 Author Members Share Posted July 3, 2011 Yup, I'm told spreading the angle of the X will boost the bass response by loosening up the lower bout. I intend to extend both ends of the X braces are to into the kerfing but with one exception (which gitnoob has mentioned previously) the rest are to be chiseled short. Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 3, 2011 Members Share Posted July 3, 2011 Originally Posted by kwakatak I intend to extend both ends of the X braces are to into the kerfing.... I was curious about why builders tuck, so I asked one. The answer was that it simply helps keep the braces on the top. Makes sense. If you're going to tuck, and you still want a nice bass response, go thin on the ends -- like 1/16" at the tucked end. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 4, 2011 Author Members Share Posted July 4, 2011 Progress has certainly been slow and tonight was no exception. I'm still trying to figure out what the deal is with the neck block. Tonight's headache was trying to figure out why there was nearly 1/2" of extra height on the sides at the neck joint than the height of the block according to the plans. If my sides are too tall there then there would be a LOT of sanding to do. Is the block too short then? I dunno. Regardless, I was too mentally fried tonight to even find the centerline of the block's mortise. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 7, 2011 Author Members Share Posted July 7, 2011 Put the 3rd attempt at a neck block in last night. I have to let it set before moving on to kerfing. My mold has many imperfections and limitations so I needed to put some shims in to get a tighter glue joint: If this doesn't work then I'll probably have to take it out of the mold to get even pressure all around. The mold seemed to get in the way of the clamps. Link to comment Share on other sites More sharing options...
Members knockwood Posted July 9, 2011 Members Share Posted July 9, 2011 How's it going, Neil? Any further movement on this guy?I just slapped the blocks into git #2 (I'm not done with #1 yet, but WTF). Have you ever watched Robert O'Brien's vid on blocks? He slaps 'em in and then quickly removes everything from the mold, then finishes clamping. I started a "practice run" and realized I would never be able to move quickly or smoothly enough to make that happen without getting all crazed and making a big mess of the operation, so I did essentially what you did - just flipped the mold on its side. I love O'Brien's instructional vids, but the guy makes everything look so easy... No way I could ever pull anything off the way he does. Let us know how you're progressing, man. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 10, 2011 Author Members Share Posted July 10, 2011 Sorry, knock. No progress to report. It's been stop and go with long breaks between sessions and even when I do get something accomplished I often have to tear it apart and do it over. This time I just glued the block in with Titebond and spent the next 10 minutes putting on clamps and shoving those shims in so that the sides came in full contact with the block. After that all you can do is let it sit until next time. There was no squeeze out which has me a little concerned but my friend called and told me he pulled all the clamps off and it looked solid. We'll see when I go back on Monday. If all goes well I kerf the top rim. I'm trying my best not to rush since I feel like I'm lagging. So you're on your second build already? Cool! What will it be this time? A uke? I'm still debating on what I'd do next. Do I go simple and just do a dread (my friend has all the molds and templates from Blues Creek) or do I try this MJ in a different configuration? Link to comment Share on other sites More sharing options...
Members knockwood Posted July 10, 2011 Members Share Posted July 10, 2011 Originally Posted by kwakatak Sorry, knock. No progress to report. It's been stop and go with long breaks between sessions and even when I do get something accomplished I often have to tear it apart and do it over. This time I just glued the block in with Titebond and spent the next 10 minutes putting on clamps and shoving those shims in so that the sides came in full contact with the block. After that all you can do is let it sit until next time. There was no squeeze out which has me a little concerned but my friend called and told me he pulled all the clamps off and it looked solid. We'll see when I go back on Monday. If all goes well I kerf the top rim. I'm trying my best not to rush since I feel like I'm lagging. So you're on your second build already? Cool! What will it be this time? A uke? I'm still debating on what I'd do next. Do I go simple and just do a dread (my friend has all the molds and templates from Blues Creek) or do I try this MJ in a different configuration? I'm sure all is well with your blocks - looks like you did a good job clamping those buggers in there. I had kind of minimal squeeze-out on my neck block today... but that's because I had a huge brain fart and planed chamfers onto the side of the neck block facing the side rather than just the side facing inward... I'd been watching O'Brien's vid on how he likes to make the insides of his gits look nice and pretty... la la la I chamfered the wrong side of my neck block. Not really a big deal, but I did lose a little bit of adhesion surface at a place where I couldn't really afford to give up a lot. My idiot move for the day (I make at least one big one every day just so I know I'm me). Anyway, the beveled edges facing the side made it kind of impossible to see the squeeze-out when I glued that block in... #2 is a 14-fret Cocobolo & Adi 000 I'm making for my cousin - as a surprise. If I screw it up royally, the surprise will be a very fancy flyswatter for my wife. Link to comment Share on other sites More sharing options...
Members rickoshea Posted July 10, 2011 Members Share Posted July 10, 2011 it all looks great Neil ... your block looks well clamped in too. I find a longitudinal spreader running from the tail block to the head block gives easily enough force to ensure a good contact between the block and the rim. My moulds are never perfect either but then I dont know how its possible to get them utterly perfect. Unless you're Rob O'Brien Knock .. I did that with my first build, but I bevelled the wrong sodding side of the headblock, on both sides, and had to repair it with strips of mahogany. That was a screw up to match anything you've done Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 10, 2011 Author Members Share Posted July 10, 2011 Originally Posted by rickoshea it all looks great Neil ... your block looks well clamped in too. I find a longitudinal spreader running from the tail block to the head block gives easily enough force to ensure a good contact between the block and the rim. My moulds are never perfect either but then I dont know how its possible to get them utterly perfect. Unless you're Rob O'Brien You mean like this one? Knock, that's pretty ambitious to do cocobolo as a second build. Are the sides pre-bent? You do know that the dust is highly allergenic, right? Link to comment Share on other sites More sharing options...
Members knockwood Posted July 11, 2011 Members Share Posted July 11, 2011 Originally Posted by rickoshea Knock .. I did that with my first build, but I bevelled the wrong sodding side of the headblock, on both sides, and had to repair it with strips of mahogany. That was a screw up to match anything you've done I doubt that last part, man. I'm pretty dumb. Originally Posted by kwakatak You mean like this one? Knock, that's pretty ambitious to do cocobolo as a second build. Are the sides pre-bent? You do know that the dust is highly allergenic, right? Your mold looks pretty freakin' good from here, Neil. I have no doubt that when it's all done, your git will kick ass. I'm pretty impressed that you made the mold yourself. I'd have screwed that up, no doubt. Rick is right about them all being imperfect, though. I had to shim the 12-fret 000 mold. I'm using one from LMI now, and they even caution on the accompanying paperwork that there may be some variance. They're right. If I tightened the spreaders to the point where there were no gaps at all, I have no doubt I'd crack the sides. I'm not being graded on this, though, so screw it. Yeah, the cocobolo sides were pre-bent. I just done buy'd me a bender recently, but the first set of sides I try to bend will NOT be cocobolo. I don't seem to be having too bad of a reaction to the stuff - a little sinus trouble is all, but I think I react worse to spruce dust (it makes me sneeze like a madman). I wore a mask for a while, but I find them pretty irritating after more than an hour or two, so I dispensed with it. I figure I probably gained a pound or so in cocobolo dust weight... Woke up feeling like I had a cold, but I'm all right now. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted July 11, 2011 Members Share Posted July 11, 2011 Originally Posted by rickoshea . My moulds are never perfect either but then I dont know how its possible to get them utterly perfect. Unless you're Rob O'Brien Leaned a trick for mold making and side bending. I clamp four pieced of 3/4 MDF together (actually I bolt them together with flathead machine bolts that I countersink the heads so that one face is flat). Take your plans to Kinkos and get a couple of full size copies made, cut one out and trace onto the stack of MDF making the centerline one side. Cut them out very carefully with a band saw, try to make all the curves as smooth as possible with no starts and stops or backup. The inside pieces become your molds for bending the sides - I just bought a Fox bender and make them fit into it but you can sure use a hot pipe and referenece them. The outside pieces become your building mold. If you bend the sides to fit the outside, then they should be very close to fitting the building mold. One more trick, I only used three of the four inside pieces for the Fox mold. At the same time I bent the sides, I also did the wood binding pieces. I just taped them to the fourth inside piece so they would hold shape until I was ready to bind the guitar (which was a couple of months later). They fit perfectly. If this doesn't make sense, I can post some pics. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 11, 2011 Author Members Share Posted July 11, 2011 Makes sense to me. I would've done exactly that had I ever used a band saw before. MDF would've been a bit sturdier - and heavier too - but it really tore up the bandsaw blade. One word of warning: photocopies are not always accurate so be sure to ask if the copier is properly calibrated. When I made copies of my plans they were actually stretched a bit. I used one to trace templates for the side and found that it was actually a good 1/4" longer than the true plans: As for the bending form cutouts, there's a little wiggle room in the final shape since the wood will spring back some. As long as the sides of your mold are uniform and perpendicular to the face of the mold (bandsaw blades do tend to bend) you should not have to worry about "cupping" where the sides will be bowed. That's another problem I ran into which is why I redid my mold with birch plywood and pine spacer blocks - and it required a LOT of checking with a straight edge. You also need to take into account for the thickness of the wood itself as well which allows for more breathing room with regards to accuracy of the shape of the bending forms. In my plans' case there was a 1/8" gap between the curve of the outside mold and that of the bending form so that the form is actually smaller than the shape on the plans. Also, when using a bending form like this, you have to drill a large hole to accommodate a bolt to hold it still within the bending machine. Then you have to have the form sit flush to one side of the machine. If you've pre-profiled your side (so that the back rim is tapered) that side will be your top rim. The next step is important: after you're done bending your first side, slide the bending form to the other side of the inside of the machine or else you will bending two identical sides. I bent two left sides the first time - my first build nearly had an accidental Manzer wedge! Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted July 12, 2011 Members Share Posted July 12, 2011 Here is he side bending mold for the Weissie the body mold and the binding piece which had been taped to one of the cutouts All made from the same pieces of MDF Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 12, 2011 Author Members Share Posted July 12, 2011 Wow, that looks mighty clean there, Freeman! I hope I can be that efficient when I get a few more builds under my belt! BTW, top kerfing went in on last night. Pics to follow but you've all seen it before. There are just lots of clothes pins around the rim and not much to actually see until they come off. The back rim will be a little trickier. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted July 12, 2011 Members Share Posted July 12, 2011 Originally Posted by kwakatak Wow, that looks mighty clean there, Freeman! I hope I can be that efficient when I get a few more builds under my belt! This one was trickier than most, the back tapers towards the headstock so the mold had to get thinner and it holds the head block in alignment with everything else. There weren't any instructions (one thread thought that Weissenborn didn't use molds) so I pretty much just winged it. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 12, 2011 Author Members Share Posted July 12, 2011 Pics as promised. Three $1 bags of clothespins and I still had a lot let over. Reverse view: Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 21, 2011 Author Members Share Posted July 21, 2011 I chiseled away the extra material above the neck block and finished up the kerfing last night. Side slats are next. It isn't perfect but I'm hoping that it'll all come out when I use the radius dish to sand the profile. Link to comment Share on other sites More sharing options...
Members knockwood Posted July 21, 2011 Members Share Posted July 21, 2011 Perfect, schmerfect. Looking very good, Neilio! Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 21, 2011 Author Members Share Posted July 21, 2011 Originally Posted by knockwood Perfect, schmerfect. Looking very good, Neilio! I'm OK with a little glue squeeze-out but I'm mainly concerned about the taper on the back. We'll see when I sand it with the radius dish. I was given some advice to keep the area around the waist higher but I'm having second thoughts about the line of the kerfing. I may end up sanding the kerfing down a bit further than at the ends. We'll see how it goes. Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 21, 2011 Members Share Posted July 21, 2011 I think the kerfing is very forgiving. You can sand half-way through it if you need to. Looks like you're almost ready to put the plates on there. Didn't you rebrace your top? I don't recall seeing pics. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 21, 2011 Author Members Share Posted July 21, 2011 I'm hoping the kerfing gives me some play with regards to sanding the back profile. I took the block plane to the upper bout only up until the curve but the waist area is probably 1/8" higher than it should be. The top rim is good to go though. I'm looking forward to "driving the bus" as John Hall describes the process of sanding with a radius dish! As for the plates, my top and back plates have no braces on them at all. They're sitting on sticks up on a shelf in my friend's workshop which is around 35% RH thanks to a dehumidifier that he empties daily. Once the side's braces are on I'm moving back on to the top. If you have any tips for voicing I'm all ears! Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 21, 2011 Members Share Posted July 21, 2011 Get a copy of Somogyi's books. He'll talk your ear off without actually telling you anything. All I can tell you is that stiffness seems to matter more than the bracing pattern. The pattern just controls directional stiffness (that modal stuff), but it's not something you can really test since it's not easy to isolate the different modes. The top will be stiffest along the grain, so aim for longitudinal flexibility and a "musical" tap tone. (And ask me again once I've built a few guitars. ) Link to comment Share on other sites More sharing options...
Members rickoshea Posted July 22, 2011 Members Share Posted July 22, 2011 great stuff Neil ... she's looking mighty fine ... mighty fine indeed Lovely shape that Jumbo too! I think at least 15 guitars are needed to be built before knowing anything at all about voicing. FK put in a great quote from someone on one of the luthiers forums which is so true. The first (whatever number .. I think it was 15) guitars you build are boxes, then you start building musical instruments. Gary, Jerry and some of the French fellas here just tell me ... you never learn it all, and these guys are luthiers. You can listen for a "bell like" ring and some sustain on tapping but so much depends on where you hold the board, where you tap, what part of your bloody finger you tap with etc. Heres a nice wee method : hope this helps some Link to comment Share on other sites More sharing options...
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