Greetings, first of all I’d like to thank this whole community, this forum is the library of Alexandria for almost anything related to stringed instruments, not just bass, however that is what we are here for. The contributions are truly amazing and I have found myself going through thread after thread just addicted to this knowledge, you guys have inspired me to become an amateur luthier. I’ve lurked for a long time and I’d greatly appreciate any help with this project.
I apologize this is long and a lot of questions, I hope you guys don’t find it too much; I took a couple of hours and reconsulted the different threads to make sure I’m not asking questions that I could just find on the forum; all this reading and thinking has finally made feel like I can move forward, but I have several questions.
Here is the situation: I have a bass with a neck that has a 12th fret kink and forward bow (I am completely positive these are the issues the neck has) and I want to learn how to do heat treatment and TOW reinforcements with this neck.
For reference I have 12k TOW. If Mr. Bruce Johnson and dwizum could give their thoughts on this that would be awesome.
So, my questions are:
1). Since I don’t have access to a router to deepen the truss channel to increase mechanical advantage of the TOW, and my lackluster chiseling skills may risk deepening the truss route incorrectly, what do you think would be the best way of installing the TOW on the backstrap of the neck? I have thought of three possibilities:
3). How deep should I cut in or chisel the slot (chisel in case you find that viable)?
4). I read in Stabalizing a Neck with a 12th Fret Kink Using Carbon Fiber Threads page 1 post # 6
Bruce mentioned about lightly twisting the TOW, what do you think he meant by that?
5). I also see in that post that the OP didn’t cover the slot, if I can’t find a fitting veneer or wood to do a plug I may have to leave it open at least temporarily, do you think that may affect things?
6). From what I’ve understood it would probably be necessary to add more TOW from the neck heel to around the 10th fret for more reinforcement there, correct?
7). I have a very specific wish that I would like to know if the TOW reinforcement will allow: there is one thing for which the bow forward is useful for me, and that is for down tuning, I play different styles of music and the sonority of standard gauge strings down tuned A to C (five steps down from standard) is very fitting for one of them, and the big arc of the forward bow allows for good action at that very low tension with a booming sound with a strong fundamental, similar to a short scale bass but clearer and with more sustain.
Basically I want the TOW to prevent a forward bow and kink from ever developing again, while providing enough range to get proper relief for both standard tension and low tension situations with adjustment of the truss rod to give me that flexibility of use. I think getting good relief after reinforcement under low tension would require the truss rod to be almost or completely loose.
Could you give me an idea on how to calculate how many layers of TOW to use on the body to neck transition and how much on the rest towards the headstock to achieve this?
8). Since the TOW strength would act based on its height relative to the depth of the neck, cutting the 12K to 6K or so size or maybe even narrower would be better regardless of the method above and use less TOW in total since there will be a couple of strands one over the other in layers, right? Since the slot made from option 1 would be a single circular saw width (around 2mm or a little over 1/16” I think) I may have to reduce the tow width a lot. I don’t how good a result I could get from widening the slot by passing neck to the saw again a saw width to the side.
9). Since the channel in possibility 1 would start from the very back of the neck heel onto the 5th fret, do you think getting rid of that wood in the center would create a possibility for a crack forming from the heel down the centerline of the cut channel? Would the epoxy help prevent that?
10). Another important matter is that the west systems marine epoxy that most recommend is extremely out of my budget in my country. I located a reasonably priced nationally made 1:1 epoxy, in the video they made it looks gel like and has a 20 hour cure time, do you think that could work?
They also have a 2:1 epoxy, but I don’t know what’s better for this application, from what I’ve understood you want the thinnest possible and slow curing to soak the TOW.
I’ve read that heating the wood can make the epoxy thinner but also faster curing, I don’t know if that could be useful.
11). How viable do you think hide glue is for this, seeing that it is often used for instrument building and repair and can be thinned depending on the application?
Best regard, best wishes, and thank you all from Colombia.
I apologize this is long and a lot of questions, I hope you guys don’t find it too much; I took a couple of hours and reconsulted the different threads to make sure I’m not asking questions that I could just find on the forum; all this reading and thinking has finally made feel like I can move forward, but I have several questions.
Here is the situation: I have a bass with a neck that has a 12th fret kink and forward bow (I am completely positive these are the issues the neck has) and I want to learn how to do heat treatment and TOW reinforcements with this neck.
For reference I have 12k TOW. If Mr. Bruce Johnson and dwizum could give their thoughts on this that would be awesome.
So, my questions are:
1). Since I don’t have access to a router to deepen the truss channel to increase mechanical advantage of the TOW, and my lackluster chiseling skills may risk deepening the truss route incorrectly, what do you think would be the best way of installing the TOW on the backstrap of the neck? I have thought of three possibilities:
- Use a circular saw with a guide (I do have access to that, my dad made a DIY saw table for himself) set at the correct angle for the neck taper so that I can cut a straight slot (I’m guessing a depth of 3/16” to 1/4”, I’ll have to measure how much wood is there after I remove the truss rod, I thinned the neck several years ago) in the backstrap, then epoxy the TOW inside there and cover with a “skunk stripe” or long plug of a similar wood (I’ll try to get maple).
- Practice chiseling in a flat plank to make a sort of “ditch” on the back strap for the TOW to be epoxied on. Chiseling the relatively straight surface of the back strap should be a lot easier than the scooped truss channel for a beginner. Then cover with veneer.
- Roughen up the back strap and epoxy the TOW directly on it? I’m guessing I could also put a layer thicker epoxy over the tow and polish it so that it isn’t too “sticky” for sliding my thumb.
3). How deep should I cut in or chisel the slot (chisel in case you find that viable)?
4). I read in Stabalizing a Neck with a 12th Fret Kink Using Carbon Fiber Threads page 1 post # 6
Bruce mentioned about lightly twisting the TOW, what do you think he meant by that?
5). I also see in that post that the OP didn’t cover the slot, if I can’t find a fitting veneer or wood to do a plug I may have to leave it open at least temporarily, do you think that may affect things?
6). From what I’ve understood it would probably be necessary to add more TOW from the neck heel to around the 10th fret for more reinforcement there, correct?
7). I have a very specific wish that I would like to know if the TOW reinforcement will allow: there is one thing for which the bow forward is useful for me, and that is for down tuning, I play different styles of music and the sonority of standard gauge strings down tuned A to C (five steps down from standard) is very fitting for one of them, and the big arc of the forward bow allows for good action at that very low tension with a booming sound with a strong fundamental, similar to a short scale bass but clearer and with more sustain.
Basically I want the TOW to prevent a forward bow and kink from ever developing again, while providing enough range to get proper relief for both standard tension and low tension situations with adjustment of the truss rod to give me that flexibility of use. I think getting good relief after reinforcement under low tension would require the truss rod to be almost or completely loose.
Could you give me an idea on how to calculate how many layers of TOW to use on the body to neck transition and how much on the rest towards the headstock to achieve this?
8). Since the TOW strength would act based on its height relative to the depth of the neck, cutting the 12K to 6K or so size or maybe even narrower would be better regardless of the method above and use less TOW in total since there will be a couple of strands one over the other in layers, right? Since the slot made from option 1 would be a single circular saw width (around 2mm or a little over 1/16” I think) I may have to reduce the tow width a lot. I don’t how good a result I could get from widening the slot by passing neck to the saw again a saw width to the side.
9). Since the channel in possibility 1 would start from the very back of the neck heel onto the 5th fret, do you think getting rid of that wood in the center would create a possibility for a crack forming from the heel down the centerline of the cut channel? Would the epoxy help prevent that?
10). Another important matter is that the west systems marine epoxy that most recommend is extremely out of my budget in my country. I located a reasonably priced nationally made 1:1 epoxy, in the video they made it looks gel like and has a 20 hour cure time, do you think that could work?
They also have a 2:1 epoxy, but I don’t know what’s better for this application, from what I’ve understood you want the thinnest possible and slow curing to soak the TOW.
I’ve read that heating the wood can make the epoxy thinner but also faster curing, I don’t know if that could be useful.
11). How viable do you think hide glue is for this, seeing that it is often used for instrument building and repair and can be thinned depending on the application?
Best regard, best wishes, and thank you all from Colombia.
