Juntunen Guitars Posted January 13, 2012 Report Share Posted January 13, 2012 I started an acoustic in tech school on monday for a class. It's being made with padauk for back and sides and bearclaw sitka for the top, sitka braces, cocobolo fingerboard, headcap, and bridge. So far I have the top glued, cut out, thicknessed, the back to jointed and ready to be glued this afternoon and I have the brace stock cut. I am stuck until next week for now since I have to wait for Stewmac to send my rosette. I will post pictures tonight after class and give a more in depth spec sheet on the guitar. Quote Link to comment Share on other sites More sharing options...
Robbinst Posted January 13, 2012 Report Share Posted January 13, 2012 sounds like its going to be a nice build, I'm looking forward to the pics! Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 14, 2012 Author Report Share Posted January 14, 2012 Specs on the guitar. Top: Sitka spruce with bearclaw figure Back and sides: Padauk Bridge: Cocobolo Headcap: Cocobolo Fingerboard: Cocobolo Brace wood: Sitka spruce: Rosette: Stewmac's three ring heringbone. Binding: Either bloodwood or maple Purfling: B/W/B plastic purfling Nut and saddle: Bone Frets: I kind of am thinking of doing something different with this guitar, if I end up doing it you all will see later. It's being built on a Martin scale so 25.4" scale length and has a Martin brace pattern I may play around with the bracing if we are able to but otherwise it will be off the Martin plans. Originally I was going to put a cutaway in it but I guess we aren't allowed to here. Here are the pictures of progress so far. Side mold This is the work board I was making. It is a quarter sheet of plywood cut in half and glued on top of each other then I sanded the edges flush then it was ran through a timesaver to thickness it down so both sides were flush. Screws go in the side of it later for the bungie cord used to glue the top down, I will have pictures of that when I get to that point. When the workboard is done You reccess two holes and using lag bolts screw in a block of wood to the bottom. It makes it so that when you glue and voice the top you can clamp the workboard in a vice so it won't move anywhere. Finger planes are nice for carving braces. This one is a 35mm blade if I remember right but it is about $35 from Lee Valley. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 14, 2012 Author Report Share Posted January 14, 2012 Onto build pictures! Here is the top in the clamping jig. This jig is easy to make, basically it's a piece of plywood reinforced with 2x4's on the bottom and has one board screwed into the edge to but up the wood against. It works by when you puit the glued wood in there you fit 4-5 sets of small wooden blocks cut corner to corner inbetween the top/back wood and then you clamp another board behind those. The reason the little pieces are cut is so that you can push them together with two blocks of wood and that acts as the clamps. I forgot to take pictures of the little pieces but I will try to get some next week. As a side note, I am using titebond 2 for glue. It's not the best to use since it's water based and makes the wood swell but it's a nice glue to use either way plus it is good for about 2 years compared to a couple weeks like hot hide glue is. Titebond 1 is the better glue to use for guitar making. I typically use titebond because that's all I have around usually and it's handy for repairing cracks in acoustic tops particularily because since it makes the wood swell it helps close the cracks up better. I would avoid using epoxy for this because if the top ever did crack along the glue joint, which it likey would even with epoxy over time, it couldn't be reheated easily, yuou would almost have to remove the top to make a nice clean repair unless you really knew what you were doing. I think it's better to use titebond or even better hot hide glue since it can be reheated easily (Titebond 1 is easier to heat than Titebond 2) The only problem with hot hide glue is getting the mix right and that once it's out of the glue pot you have barely more than a minute to spread the glue and clamp it down tightly before it jells to much to have a good bond. Some people say hot hide glue is better for vibrations to and add to the acoustic quality but I'm not sure on that, I haven't used it enough to have an opinion. Top freshly out of the glueing jig. After it's out you want to measure 8.5" out on each side and cut the top to be 17" wide. The reason for this is to when you run it through a drum sander it will be more likely to not take off more wood in one area than another. Be sure to save the cutoffs for a center strip down the glue line on the back on the inside of the guitar, you want to be sure you have long strips that are cross grained. Plus it never hurts to have extra wood just in case. Cut out the top a little oversized then at the top edge where the neck meets the body sand it down flush to the outline of the guitar. This way when you measure for the soundhole and rosette you can have a spot where you can always measure from so you don't get off centered. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 14, 2012 Author Report Share Posted January 14, 2012 Starting to mark out the braces for the top. LMI sells brace blanks, if you get them in bocks like I have in this picture it's actually cheaper and easier in a way. The sitka blanks I bought I got all the top braces out of it in 5 strips, I cut them oversized and longer than needed because they still need to be radiused for the tops radius and they need to be final thicknessed down still. I had to do some wierd angled cuts to get quartersawn wood out of them but I Will explain that later. Here is the jointer for the thinner woods. You want to use these for thin woods like the top and backs, It's really frustrating sometimes but you can get better glue joints out of it than using a power jointer since a top is to thin for one even if you hold them together instead of doing them one at a time. If you use these jointers it's a good idea to sharpen the blade everytime you go to use it, especially on the back woods since they are harder, when the blade is dull it gets super hard to cut anything cleanly. And be carefull with oily woods. My hand slipped today and it deflected off my finger nail (took a chunk of the skin with it) and decided to dig into my knuckle and leave a nice chunk on the blade. It didn't feel too good. For those who don't know about looking at grain direction, when you are planning by hand you might notice that it's harder to plane in one direction than the other. That's because of the grain runout. A tree doesn't grow straight, they grow in a twisting motion, you can see this mostly on acoustic tops if you look at them in the light, one side will be darker than the other, that's because of grain run out. This sad attempt at drawing in paint on my laptop is my attempt at explaning this. The way I showed is the bad way to plane. You have a higher chance of splitting deep into the grain or haveing tear out. If you switched the planes direction in that picture then you are planning the right way. And the last picture for today is the back before I jointed it. I have some more on my phone of the back jointed, in the glueing jib and with my templates on it but I can't get them off my phone quite yet. Quote Link to comment Share on other sites More sharing options...
Mors Phagist Posted January 15, 2012 Report Share Posted January 15, 2012 Nice! I'd like to see how this one turns out. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 17, 2012 Author Report Share Posted January 17, 2012 Back being glued Back out of the jig Headstock template Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 17, 2012 Author Report Share Posted January 17, 2012 I started the rosette today. I decided to combine all three rings into one big one. I used a laminate router to cut the channel. I good tip to avoid chipping and to help keep dyes in the rosette from spreading to the top is to spray lacquer over the area first. Since I'm using super glue and it has a tendancy to bleed colors I sprayed lacquer first. Gluing the rosette later this afternoon. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 18, 2012 Author Report Share Posted January 18, 2012 Rosette slot Glueing in the rosette. When you buy premade rosettes be sure to check their width in multiple places, there was a .006" difference in the thickness depending on where you measured it at so I had gaps here and there. I used titebond since it has water in it so it would help expand the rosette a bit which helped out, there are no gaps now. Rosette installed and soundhole cut out. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 18, 2012 Author Report Share Posted January 18, 2012 I got some of the braces ready yesterday too and glued the X-brace today. This is a jig for radiusing the bottoms of braces. Matrin's have 25' radius on their tops. This jig is held in place in the miter slot on an edge sander and the piece the brace is clamped to has the radius cut into it. The part in the miter slot has a stop just before the belt that you pivot the clamping jig on to radius the braces. Braces drawn out. X-brace slotted and ready to be glued. Martin guitars have a 98 degree X-brace. You measure an X-braces angle by using the angle facing the soundhole. Using a go bar deck to glue down the X-brace. I used titebond 2 here because it doesn't give as easily as hot hide glue or regular titebond does. The top is sitting in a 25' radius dish for glueing. Quote Link to comment Share on other sites More sharing options...
madawgony Posted January 19, 2012 Report Share Posted January 19, 2012 Looking real good so far. Quote Link to comment Share on other sites More sharing options...
demonx Posted January 19, 2012 Report Share Posted January 19, 2012 Looks very good. Can't wait to see more progress on this one. There's something about acoustic builds that fascinates me Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 20, 2012 Author Report Share Posted January 20, 2012 Looks very good. Can't wait to see more progress on this one. There's something about acoustic builds that fascinates me Thanks. I agree there is just something about them that always draw me to an acoustic build. I have three braces left to glue tomorrow and then I will be bending the sides as well. I've been going through a lot of sandpaper too, this padauk just cloggs it right up. Quote Link to comment Share on other sites More sharing options...
demonx Posted January 20, 2012 Report Share Posted January 20, 2012 I've been going through a lot of sandpaper too, this padauk just cloggs it right up. One thing I do to extend the life of sandpaper (not sure if you've ever heard of this) is when I'm doing a lot of sanding I keep an air hose close and I blast the sandpaper clean and keep using it. Means you get about 4x the use out of 1 piece and since the rolls I use cost my nearly $70 a roll I try get as much out of them as I can. Just be aware that if after you blast it, if theres chunks left they'll leave scratches. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 20, 2012 Author Report Share Posted January 20, 2012 One thing I do to extend the life of sandpaper (not sure if you've ever heard of this) is when I'm doing a lot of sanding I keep an air hose close and I blast the sandpaper clean and keep using it. Means you get about 4x the use out of 1 piece and since the rolls I use cost my nearly $70 a roll I try get as much out of them as I can. Just be aware that if after you blast it, if theres chunks left they'll leave scratches. I usually do that but I have no air hose in my class and it would take to long to have to walk out into the shop every minute or two to blow the dust off. I use self adhesive from Grizzly and just pull the paper up and stick it back down to get all the dust off, it makes it look practically brand new but not with oily woods. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 20, 2012 Author Report Share Posted January 20, 2012 More braces glued Shapping the sides before bending Thicknessing the sides in the Timesaver This is what I mean by using a lot of sand paper, that was abot 5 passes. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 20, 2012 Author Report Share Posted January 20, 2012 Time to shape some braces on the top I used a block plane to plane a taper into the braces then a chisel to shape and a finger plane for the finalizing then I just used a sanding stick. I like to use rulers as sanding sticks because they will usually bend a little bit so you can sand tight areas a little better. I just realised these posts are out of order. Basically glue the X-brace first, shape it then glue the rest of the braces and shape them. I will post more on glueing braces later today. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 21, 2012 Author Report Share Posted January 21, 2012 Got the sides bent yesterday. I used a heating blanket from LMI for heat. The sides are wetted down then a paper towel is folded over them to hold more moisture and then tin foil is wrapped to keep the steam in. The heating blanket goes on top of that and two pieces of spring steel are put on the top and bottom of that. The bending process should take 3 minutes tops. Plug the blanket in wait 45 seconds, clamp the waist then bend the lower bout slowly and then the upper bout. Let it sit for about 40 minutes then re-align the side if you need to and re-heat it for 3 minutes, this will help keep the side in that shape when you take it out without the side springing back a bit. I love the look of Padauk You want to make sure that you get everything centered right or the sides won't line up right. I added an inch on each end just in case something got off centered so I could work with it a little. I also finished bracing the top. Quote Link to comment Share on other sites More sharing options...
3DogNate Posted January 25, 2012 Report Share Posted January 25, 2012 Nice! I did a Padauk and Bearclaw Sitka OM sized guitar a couple of years ago for a guy... Great combination... I still get notes from him praising it. What'd you use for the bridge plate is that also Cocobolo? Just making sure it's not Indian Rosewood. Padauk is such a nice back and side wood... love it. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 25, 2012 Author Report Share Posted January 25, 2012 Nice! I did a Padauk and Bearclaw Sitka OM sized guitar a couple of years ago for a guy... Great combination... I still get notes from him praising it. What'd you use for the bridge plate is that also Cocobolo? Just making sure it's not Indian Rosewood. Padauk is such a nice back and side wood... love it. Yes it is Indian Rosewood. Dreadnaughts have a lot of base so because of that a lot of overtones that need to be dampened a bit, Indian Rosewood keeps the tone but filters the overtones in a way. I also left the treble side lower portion of the x-brace unscalloped to help add some more high end to the mix but not too much. I still like the bass they give. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 25, 2012 Author Report Share Posted January 25, 2012 After the sides are bent you want to cut off the extra so you can close the mold up. The mold I am using has a hinge on one side. It's ok if there is a gap between the sides since they will get covered later. Gluing in the blocks. I use titebond 2 only the neck block because when it needs a neck reset (all guitars should at some point that's why you never use epoxy) titebond 2 is water based and more water resistant than hot hide and titebond 1 so when you go to steam the neck off it won't have the risk of steaming the neck block with it. Sanding the inside of the ribs for kerfing Finally figured out what cheetos are made of Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 25, 2012 Author Report Share Posted January 25, 2012 The back Gluing in the center lining on the inside of the guitar. This runs from block to block, don't cut out spaces for the braces yet just glue in the strip, you want to add about 1/8th" extra into where the blocks go on each side. You can trim that back later and get a good fit. The back braces and center lining are glued in a 20' radius dish, the top was 25'. Marking out where the braces go. Quote Link to comment Share on other sites More sharing options...
demonx Posted January 26, 2012 Report Share Posted January 26, 2012 Looks great! Good pictures too. Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 26, 2012 Author Report Share Posted January 26, 2012 Looks great! Good pictures too. Thanks. Center seam in You want to round over the center strip. I just took a block of wood and held it to the spindle sander Glueing the kerfing Notching the slots for the back braces, I use a chisel to cut through the strip then a smaller chisel with the bevel side down to pop the braces slot out. And back braces Kerfing done And slotted the fingerboard Quote Link to comment Share on other sites More sharing options...
Juntunen Guitars Posted January 29, 2012 Author Report Share Posted January 29, 2012 Here are some pictures of last weeks work. I got the top voiced. I did this using Dana Bourgeois's method, if anyone is interested you can check out his articles here Notching the kerfing for the side braces. When you do this remember that you will only be able to see the notches on the back kerfing and not the kerfing bordering the top so use the bottom to mark this all first. That will it will look cleaner too. This picture shows the top edge. To find the places to when the braces go count all the kerfing slots on a side and divide by 5 if you want 4 braces or by 6 if you want 5 braces. I am using 4 braces and had a decimal answer so I just changed it a little, so each brace isn't spaced evenly, it ended up being 18,18,19,18 kerfing slots between each brace. Back braces being shaped. Side braces glued. These help to prevent cracks from going around the side if the guitar was ever cracked, these also help to make repairs of cracked sides easier since the crack can't spread. Using a radius dish to put a 20 foot radius to the back gluing surface. The top gluing surface was radiused to 25 foot Marking the kerfing for where it will get notched to fit the braces through. Quote Link to comment Share on other sites More sharing options...
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