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  #16  
Old 02-25-2015, 08:07 AM
charles Tauber charles Tauber is offline
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Originally Posted by Twilo123 View Post
so i glued the x-brace on however i have some questions maybe someone is willing to answer.

1. usually when i see a build the braces are snug tight to the inside edges of the side. as you can see in my case they are short and do not run all the way to the edge. how does this affect everything? do the braces have to run all the way to the edge (see pic 1).
There are three common approaches to deal with brace ends near the sides.

First, to inset them within the lining. Having the lining "trap" the brace ends prevents the ends from coming loose.

Second, is to stop the braces short of the linings, but feather the thickness of the brace, at its end, to zero. This, too, helps prevent the brace ends form coming loose.

Third, is to leave the braces somewhat thicker at the ends and then attach a buttress that sits on the end of the brace and is glued to the side. This, too, helps prevent brace ends form coming loose.

Quote:
2. just cut a piece of scrap wood slightly larger and fit it inside? if i do that once the glue dries on the top and i pull the scrap out will it pull back into original shape and just rip the glue apart from the top?
Cutting a scrap of wood to fit inside will work. It must be done before the top or back are glued on, and, preferably, before the linings are attached. Attaching the linings stiffens the sides somewhat.


There are a number of approaches to removing PVA glue squeeze-out. What is most often recommended is to let the glue squeeze-out partially dry, about 5 to 10 minutes. At that consistency, it will detach cleanly as a single "string". To detach it, one can use a chisel, a wooden stick fashioned like a chisel - that can be "resharpened" with a chisel as necessary - or using a drinking straw who's working end is cut on a 60 degree or so angle.
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  #17  
Old 02-25-2015, 10:18 AM
Ned Milburn Ned Milburn is offline
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Originally Posted by charles Tauber View Post
There are three common approaches to deal with brace ends near the sides.

First, to inset them within the lining. Having the lining "trap" the brace ends prevents the ends from coming loose.

Second, is to stop the braces short of the linings, but feather the thickness of the brace, at its end, to zero. This, too, helps prevent the brace ends form coming loose.

Third, is to leave the braces somewhat thicker at the ends and then attach a buttress that sits on the end of the brace and is glued to the side. This, too, helps prevent brace ends form coming loose.
A further note to add...

For STRUCTURAL braces, it is recommended to use method 1 or 3 above as Charles has stated. I know nothing about the inside bracing pattern of a bouzouki, so I'll use a guitar as an example.

The transverse brace at the end of the fingerboard extension near the soundhole on a steel string guitar, as well as classical guitar transverse braces, if only feathered and not inset into the lining or supported by a buttress, then any impact or stress to this area of the guitar can cause a stress fracture near the ends of the brace on the top wood. Sometimes even the brace can become delaminated from the top wood. By insetting into the lining or supporting with a buttress, the impact is transferred to the lining & sides or buttress & sides, thus giving an overall greater support. Of course, if the impact is too strong, you'll crack the instrument no matter what. But I, myself, would never build with support braces that are not inset. The same holds true of back braces. After seeing what happens to various older (and newer) guitars built in various methods, and just using a basic sense of structural engineering, it is logical to come to this conclusion.
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Old 02-26-2015, 04:17 PM
Twilo123 Twilo123 is offline
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thanks everyone. i spoke to some others (including kit seller) and for this particular item it seems i can leave as is.
thank you all for your input though. i will definitely keep this in mind when i do my 1st guitar kit build.

1. so moving forward i glued the top today (pic 1). made a makeshift plank to be able to clamp everything down and nailed near the headstock to keep the neck straight/aligned with the body.

2. i also glued the braces to the back (pic 2). the back braces were noted not to clamp to anything flat as it is curved. i put the flat edge of the braces lined up against a ruler and noticed that the braces themselves were indeed curved. is this normal in guitar world also? are the back braces supposed to be cut/edged curved and have something of a bowed back?

3. i am concerned about my glue job...as you can see in (pic 3) there is some space between back/side even though i am clamping them. quite possibly the sides were not level enough and as a result there is some space when gluing. does wood glue expand to fill gaps? my understanding is wood glue looks to attract to wood instead of fill gaps like say epoxy would. if when the wood is dry not all points have contact do i need to somehow pull the top off, re-sand until more level, and re-glue again? or could i patch with some epoxy or something for the part that is not fully stuck together?

4. also i know for some glues you should rough up the surfaces to be connected for there to be good contact. is this the same for this wood? for instance i roughed up the bottom of the braces with a blade so hoping it would help them adhere better to the back/sides. was this ok to do this or a bad idea?

5. gluing question: rather than wiping glue on wood all the time with my fingers how does everyone apply glue to various wood surfaces? i thought i saw a video of someone using a paint roller to apply glue to wood so i bought one. i figured the regular paint rollers are too soft and pieces would pull off with the glue so i found 1 that uses a harder plastic roller (pic 4) however upon trying to use it i found it was pulling off the glue as much as evenly spreading it out. i could not find any metal based roller end so i am not sure how people are using rollers or how they are applying glue other than finger/hand. maybe a brush? need something reusable though. any suggestions?
pic 1


pic 2


pic 3


pic 4

Last edited by Twilo123; 02-26-2015 at 04:33 PM.
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  #19  
Old 02-26-2015, 06:46 PM
Ned Milburn Ned Milburn is offline
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Originally Posted by Twilo123 View Post
2. i also glued the braces to the back (pic 2). the back braces were noted not to clamp to anything flat as it is curved. i put the flat edge of the braces lined up against a ruler and noticed that the braces themselves were indeed curved. is this normal in guitar world also? are the back braces supposed to be cut/edged curved and have something of a bowed back?

3. i am concerned about my glue job...as you can see in (pic 3) there is some space between back/side even though i am clamping them. quite possibly the sides were not level enough and as a result there is some space when gluing. does wood glue expand to fill gaps? my understanding is wood glue looks to attract to wood instead of fill gaps like say epoxy would. if when the wood is dry not all points have contact do i need to somehow pull the top off, re-sand until more level, and re-glue again? or could i patch with some epoxy or something for the part that is not fully stuck together?

4. also i know for some glues you should rough up the surfaces to be connected for there to be good contact. is this the same for this wood? for instance i roughed up the bottom of the braces with a blade so hoping it would help them adhere better to the back/sides. was this ok to do this or a bad idea?

5. gluing question: rather than wiping glue on wood all the time with my fingers how does everyone apply glue to various wood surfaces? i thought i saw a video of someone using a paint roller to apply glue to wood so i bought one. i figured the regular paint rollers are too soft and pieces would pull off with the glue so i found 1 that uses a harder plastic roller (pic 4) however upon trying to use it i found it was pulling off the glue as much as evenly spreading it out. i could not find any metal based roller end so i am not sure how people are using rollers or how they are applying glue other than finger/hand. maybe a brush? need something reusable though. any suggestions?
Backs (and tops) are curved to act as expansion joints so your instrument doesn't crack as it expands/contracts over RH gains/losses. As the RH rises, so should the curvature of the back and top. Reverse for falling RH.

The best glue joint is wood-to-wood. Anything less and there are more chances for trouble. This instrument won't be pulling quite as much stress on the top/back joints with sides compared to a guitar, so you have more room for error. But...

I use my finger to spread glue. When I asked my guitar building master how to get the amount of glue right, he said, "Just put the right amount of glue on!" 'Nuff said! ;-) You can smooth it with a finger and wipe the excess from your finger on the edge of a garbage can.

Certain glue joints are best NOT roughing with sandpaper or whatever. For example, centre seams in top and back should be planed then glued immediately. Braces...??? Hmmm.... Different people likely have different ideas. I've done both (sandpaper preparation and plane preparation). I think the most important thing is a consistent curvature along the length and flat surface along the width.
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  #20  
Old 02-26-2015, 06:50 PM
Jim.S Jim.S is offline
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2. Backs are usually domed or curved as it adds a bit of strength.

3. glue joints should be wood to wood if that is a air gap then it is not glued but may be okay if you are adding some sort of lining and not just relying on the top to rib joint. Wood glue does not expand unless it is polyurethane glue.

4. Wood glues best if the surfaces are planed or scraped smooth then joined soon after scraping but you can get away with sanded joins.

5. The best glue spreader for wood glue comes attached to your hand at birth with an individual print so nobody else in the workshop can steal them.

Also those brace ends on the top that do not reach the sides are best tapered down to nothing on the ends (as Charles pointed out) to defend against them coming off due to a blow in the future. You could still do that before you close the box.

One other bit of advice Twilo is to learn from any errors you make on this one then buy another kit and go again making improvements on the second one. Itain't rocket science but practice helps.

EDIT...didn't intend to double up on Ned, his post was not there when I started my reply
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  #21  
Old 02-26-2015, 08:50 PM
Twilo123 Twilo123 is offline
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Thanks everyone. I will be using binding so hopefully that will help with any gap issue....

Speaking of binding. Should I just get a router like this
http://t.homedepot.com/p/Bosch-5-6-A...?showPLP=false

Or am I better off with my Dremel and this
http://www.stewmac.com/Luthier_Tools...t.html#details
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  #22  
Old 02-27-2015, 06:20 AM
Jim.S Jim.S is offline
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I use the edge trimmer for routing the binding rebate and it seems most others do to, dremels are good for inlay but they don't have much guts. So that Bosch and a jig would be the most popular choice Twilo.
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  #23  
Old 02-27-2015, 06:32 AM
Ned Milburn Ned Milburn is offline
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Quote:
Originally Posted by Jim.S View Post

EDIT...didn't intend to double up on Ned, his post was not there when I started my reply
Reinforcement is often a good thing!! ;-)
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  #24  
Old 02-27-2015, 10:19 PM
Twilo123 Twilo123 is offline
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1. ok i tapered the braces off a bit more (pic 1) as suggested since they will not run all the way to the end. i left a little bit on the end but i did shave them down quite a bit at the end.

2. today i flipped over and glued the back (pic 2). again i see some spaces as i also noticed the back is bowed a little from gluing the angled bracing on which is normal i would think. hopefully the routing and binding will fix the space issue. i notice the spacing by where the tailblock is and i am gluing the whole tailblock so a little spacing there should be fine i would think. i bet my tailblock is not as level as i would like to believe and this may be causing the spacing issue. i did sand the sides and tailblock and had a level handy to make sure they leveled off but who knows.

3. i have a lot of extra space around some parts of the sides from the top/back being oversized initially (pic 3). i understand that i will route this off when i route for the binding. my concern is i have never done this before so i hope that the router doesn't rip the top/back instead of clean cut and mess up everything. i got this router bit set http://www.harpkit.com/mm5/merchant....ory_Code=inlay
and got the router suggested earlier in my previous post. i am hoping the rpm are fast enough that the sides cut cleanly and not rip apart. of course i will test the router and bit on practice wood quite a few times before trying on the real thing. any tips on routing binding would be appreciated! i see some youtube vids but nothing like some direct advice.

pic 1


pic 2


pic 3

Last edited by Twilo123; 02-27-2015 at 10:28 PM.
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  #25  
Old 02-28-2015, 07:07 AM
Ned Milburn Ned Milburn is offline
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You can cut off a great deal of excess by hand (saw and or rasp) before routing. Certain directions are fine for having no tear risk, but other areas will have the risk due to grain direction and router spin direction. Those dicey areas are the ones you'll want to trim only a mm or 2 at a time.
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  #26  
Old 03-01-2015, 05:33 PM
Twilo123 Twilo123 is offline
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Originally Posted by Ned Milburn View Post
You can cut off a great deal of excess by hand (saw and or rasp) before routing. Certain directions are fine for having no tear risk, but other areas will have the risk due to grain direction and router spin direction. Those dicey areas are the ones you'll want to trim only a mm or 2 at a time.
Ned, thank you for this reply and all of your others. Definitely much appreciated!!!

so i tried using the saw (pic 3). i think i will need something like a jeweler saw though for this (wonder if i can use medium blade or need something finer). when cutting the lam side with regular saw it was ok (pic 1) but when i got to the solid top it began ripping in chunks in addition to sawing (pic 2).

pic 1


pic 2


pic 3

Last edited by Twilo123; 03-01-2015 at 05:45 PM.
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  #27  
Old 03-01-2015, 05:35 PM
Twilo123 Twilo123 is offline
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clamps are off! now i start getting nervous. router ordered and on the way. once i get it on to binding...
i have never used a router in my life. of course i will test on scrap wood first but this is definitely a learning curve for me. hope i don't F it up here lol
i don't have a jig to hold the body in place while i route over it. any suggestions?

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Old 03-01-2015, 09:12 PM
gpj1136 gpj1136 is offline
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There are router jigs for cutting the binding channels that keep the binding aligned with the side. I made mine but I do not have a picture. Hopefully someone else will. You can not use the top or back to guide you because they are curved. Search the web for router jigs for guitar binding then you can decide which method you want to use. keep in mind there are simple hand held ones that are easy to make and work great. I can set mine to cut a little at a time so I have no tear out. When using the router the direction you cut makes a difference creating less tear out if you go in the proper direction. Practice on something similar to the top with round cuts. If you start at the top of the round and go with the grain you should be OK. Do not try it without A jig!!!
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Old 03-01-2015, 09:41 PM
Twilo123 Twilo123 is offline
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Originally Posted by gpj1136 View Post
There are router jigs for cutting the binding channels that keep the binding aligned with the side. I made mine but I do not have a picture. Hopefully someone else will. You can not use the top or back to guide you because they are curved. Search the web for router jigs for guitar binding then you can decide which method you want to use. keep in mind there are simple hand held ones that are easy to make and work great. I can set mine to cut a little at a time so I have no tear out. When using the router the direction you cut makes a difference creating less tear out if you go in the proper direction. Practice on something similar to the top with round cuts. If you start at the top of the round and go with the grain you should be OK. Do not try it without A jig!!!
yea i got this bit...http://www.harpkit.com/mm5/merchant....ory_Code=inlay

do i still need a jig?

i saw this http://www.stewmac.com/Luthier_Tools...plete_Set.html

doesn't my router have a base already? i wouldn't need that then right.

maybe i only need this then?
http://www.stewmac.com/Luthier_Tools...dge_Guide.html

or how about this?
http://www.stewmac.com/Luthier_Tools...ter_Guide.html

i would prefer not to have to get a full set like this
http://www.stewmac.com/Luthier_Tools...outer_Jig.html

this guy is using a heat gun to apply binding...i don't need to do this right? i can just glue and tape it on with medium blue tape right?
http://guitarbuilding.tumblr.com/binding

for instance for trimming i see this guy just going around with the router. would i not do the same thing with the bit i list above for routing the binding channel?


Or how about I do this?


Worse comes to worse I could do it by hand. Not looking forward to that method though. But it is safer....

Last edited by Twilo123; 03-01-2015 at 11:35 PM.
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  #30  
Old 03-02-2015, 08:58 AM
charles Tauber charles Tauber is offline
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The issue in cutting rabbets (ledges) for the binding occurs on instruments whose tops and/or backs are not flat. If the base of the router sits on the curved/arched top or back, the binding ledges that are created are not of uniform thickness. The angle of the router bit relative to the instrument sides changes as the router base tilts while traversing the circumference of the arched top or back. This creates ledges of varying thickness - thinner the further you are from the center of the arch.

If you are only making one or two instruments, it is easy enough to just use the router with its cutter to create the rabbets. Follow that by using a sharp chisel or files to make the rabbets uniform in thickness. If you do not, when the binding is glued and then scraped flush with the sides, the thickness of the binding will vary.

If you are to make a number of instruments, you may wish to invest in jigs that will ensure that the sides of the instrument are used as the reference for the router. As long as the base of the router is maintained perpendicular to the instrument sides - that is, the cutter is parallel to the sides - the thickness of the ledge will be uniform. As you have seen, there are numerous ways to achieve that, from attachments to Dremels to large holding fixtures. All of them will work.

Regardless, pay particular attention to the sequence in which you route. In the "parlour guitar build" video you posted, he shows this about half-way through, though doesn't explain why. He routes from the widest point in the upper bout towards the neck, from the widest point in the upper bout towards the waist, then from the widest point of the lower bout towards the waist, then from the widest point of the lower bout towards the end block. This is done so as not to "catch" the wood and sever it along a grain line. If the wood does "catch", it can take a 1/4" or 1/2" piece of the top or back when it does so. You can reglue the piece, but it is best to avoid doing so to start with. With the amount of overhang you have, nibble away at it, rather than try to remove it in a single pass of the router. If you have access to a disk or belt sander, I'd remove nearly all of the overhang that way. A sharp chisel will also work, if you have that skill.
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