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Well, here I am moving backwards again, guess I moved into celebration mode too quick yesterday after getting the neck fit on my second electric finally. I was all set to do my final fit on the angle at the heel and decided to straighten out the neck first with the truss rod. I but a block under the nut end of the neck and used a c clamp in the middle to pre-bend the neck straight so the truss rod, (double action hot rod) wouldn't be doing all of the work. Gave it a turn in one direction and could tell it was fighting me so I went the other way and instead of being easy, I heard a little tearing noise and watched as the fret board popped up a hair at the nut end. So, I want to do it right and wasn't going to just try and squeeze some glue in since this is a stress joint, and since I had to reglue the fret board on my first I wasn't too skeered so I set to peel that baby off and reglue it. When I did the first glue up I used a good amount of silicone at both ends of the truss rod, oh and one more detail: I was a little off on my truss rod channel width so I had shimmed the sides at the nuts to get a tight fit, I'd made sure that the truss rod was functioning properly before I closed it up, I ran a piece of 3/4" masking tape over the channel and got a good amount of titebond one on there. Clamped it up, left it clamped for several hours and then that was over two weeks ago.

So now I have the fret board off, I feel like I did everything right but the silicone is still wet in the channel and I've had an obvious failure. What can I do to make sure this won't happen again? Should I try epoxy at the nuts? The fret board is ziricote, should I treat the surface with something before I glue it back up? I'm a little reluctant to do anything just yet, I want to make sure I get the strongest set up possible. I've cleaned as much silicone out of the channel as I can, I've scraped the neck surface and the fret board of all old glue and waiting before I do anything else!

Thanks for getting back to me Filippo, I was verrrry careful with the silicone cause I don't really like using it around anything that gets finish either, I work as a finisher at a custom cabinet shop! One thing I noticed when I was checking the truss rod was the rear nut was almost at the end of the rods threads, it really wouldn't turn enough to give me good action after all, maybe a slight down bow but that's it. I think I'm going to give it another go with a freshly scraped fret board and leave it clamped for much longer. I had used some shims to tighten up the fit at the nuts so I'll just do that again. I went ahead and clipped four nails which I inserted into the neck to give myself some guides to glue it back on so I'm pretty much good to go.

Just so I understand do you mean that you tape over the slot where the nut and block and then trim it back so that it's about a sixteenth to an eighth away from the slot on either side of the slot, but still sitting over the nut and block?

I'm not sure I'm totally in love with these hot rods although I'm still a total newb. I watched a video on PRS and how they do theirs and I like the idea of putting the fillet over the top of the single rod, which they claim was dual action. My two gripes about the hot rod are how it's acting right on the underside of the fret board and how it doesn't give you a whole lot of meat at the back of the neck if you want to go for a thin profile neck, though I'm really happy with my first electrics neck profile and haven't had a single problem with it as far as that's concerned.

perfect Fillipo, that looks good. So what kind do you like? Allied?

I worry a little when you said that you gave it a turn. Double acting rods are very sensitive - on most of them they move twice as far for a give amount of rotation as a single acting rod (kind of like the way a turn buckle works). Here is an LMI rod that I first adjusted dead flat, then gave one full turn



Remember too that a single acting rod only acts on the ends of the neck (body joint and nut) where a double acting rod can introduce backbow by acting on the middle of the fretboard itself - again, be very careful in the way you adjust it.

fwiw - I've been using nothing but the LMI rods with no filler strips or anything else - mostly in acoustics but also in my Lester. I was going to put some bathroom caulking in to prevent rattles but the fit was so nice I left in out'

Freeman, that looks just like the hot rod I used. When I said I "gave it a turn" I didn't mean to imply I turned it one full revolution, I meant that I turned the nut with a wrench. I wasn't doing anything weird with it or trying to be too aggressive with it, I even did most of the hard work with a clamp first, again just using a little bit of pressure to straighten things out.

I think there were two things that I did wrong here. First was I didn't leave my clamps on long enough, and may have been a bit skint with my glue. Second, I've had this thing hanging around the house for over a year as I'm the slowest builder in the world and must have fiddled with the thing at some point, because the end block was nearly at the end of it's threads on the lower rod. If you take one of these and spin both of the rods equally at the same time you can actually increase the distance from the nut block to the tail block. After I took the fret board off I was cleaning it off and playing with it and when I went to put it back in the slot it was over 1/2" shorter in length. I think what happened was that when I turned the nut the energy rather than changing the length of the rod was redirected upward as the bottom rod would not turn anymore. So I think this applied a prying energy upwards towards one edge of the fretboard which would make it easier to break the glue joint than if it had been applied equally straight up or down along the whole length of the fretboard.

I'm going to give it another shot this weekend, I've already placed some marking pins into the top surface of the neck and the bottom of the fingerboard so it'll go back in the right spot. I'm going to give it a good scrape and be much more careful about my shimming this time. I had used some strips of veneer to get the truss rod tighter in the slot but there may have been a bit of slop.

I've got confidence that it'll work this time.

John, I was pretty sure that was what you meant. I always adjust the rod so it is completely neutral, dead flat, before gluing the f/b on. I just put a piece of tape over the rod, smear the glue on, pull the tape which leaves a small bit of neck wood next to the slot without glue, index the f/b and clamp it down. I don't adjust the rod at all until I'm ready to start leveling frets. I've always used Titebond but I know some folks like epoxy here.



Filippo, that is a StewMac rod - sorry. I've used both, but this one seemed to be the right length for the LP. Also, on all my acoustics I put the adjuster inside the body but on the LP I wanted it in the headstock. The SM rod has a smaller profile and required a smaller route - I thought that would make the neck a little stronger in that area (its also a scarf joint)

Also I think the idea of caulking in the slot dates to the threaded rod style truss rods. The Martin style single acting ones always had a filler strip but I think the double acting rods don't need it as long as the channel is tight.

Sorry for skewing the thread:
Freeman, on your LP build, is the fret board glued to the top plate of the body?
I have been studying LP builds and this is one area I am unsure of.
Thanks,
Dan

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I'm having some truss rod trouble as well, with the same rods. after my board was on and fretted, I measure about 0.010" between the top of my 7th fret and the bottom of my straight edge, so I've played with the adjustment of this rod, turning clockwise, as I understand this should straighten relief. I still can not get the neck dead straight so I can do my fret levelling. I've turned the rod almost 3/4 turn, the neck is still not straight, the relief is close to 0.005" at the 7th fret, but not quite close enough to do my fret work. at this point in turning the truss rod nut, it feels like it's almost too tight, if you know what I mean. I don't dare turn it anymore, for fear of it popping the fret board off, or cracking the neck. what could be the issue here? is it possible my neck is too thick, would carving it down a little more make the adjustment easier? Do I need to find some fretwire with an oversized tang? where could you find this if it would make a difference?

Yeah Freeman, you might be right about the origin of putting caulk in there, but it's still included in the stew mac instructions for installation so I did it. It seems like it's doing the same thing as the plastic tubes they put on the rods though so I may skip this from now on. I used silicone in this case because I had a freshly opened tube from doing a repair job on my dishwasher tray, and because I have been on the wrong end of silicone with regards to finish I was extremely careful.

Your picture is exactly how I did my glue up as well, but I think I'm going to take Fillipo's advice and put glue on both surfaces. For my part I never use irwin squeeze clamps for anything but temporarily holding stuff while I put real screw clamps on things. I've had too many instances of the irwins not giving me enough clamping pressure and causing a joint to slip. I use the harbor freight pony/jorgenson/bessey type clamps and drive the people nuts when I go buy them. I'm the guy who takes every single clamp off the rack and makes sure the jaws line up and the swivel pad actually swivels, if you just grab them out of the rack you'll be lucky if one in four is defect free.

Yes, don't know if it right (only electric I've ever built) but its normal to lightly glue the f/b to the top of an acoustic. As you can see in this pictures, the neck tenon is slightly narrower than the fretboard - the wider portion of the heel is where you set the final neck angle. The neck pocket was routed with the 3-1/2 or 4 degree angle (check with your pups and bridge) with the top plate standing slightly proud, like this





Here is a shot of flossing the neck angle to the body - again, I am used to doing this on acoustics so I just followed the same procedure



After the neck is glued in place I brought the top down flush with it, then glued the f/b down. Here is my clamping method, I'm guilty of using the Irwin clamps LOL



I apologize for hijacking your thread with all the pictures - I hope it helps. Also, if you are interested in building a Lester I did a very long build thread on another forum, I'd be happy to point you to it.

Mark, exactly as Filippo suggests, go slowly (1/8 or no more than 1/4 turn at a time) and let it set for a while before doing more. You should be able to adjust it completely flat.

I'll answer your question. Yes it is glued to the top just like an acoustics fingerboard is. ...Mike

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I don't use silicone but I do use a latex type of caulk. I use a few dabs along the slot to help prevent any possible rattle of the rod after glue up.

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Thanks Freeman, I would appreciate a pointer!
Dan

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I am never gonna live this down...

Warning, very long thread.

http://www.harmonycentral.com/t5/Electr ... p/31808721

I'm just curious about this rattle thing, as I've never had the issue, with either any of the guitars I own or any that I have made. My experience is that turning the truss rod just enough so it is loaded keeps anything from rattling, at least when the truss rod is installed in a reasonably fitting slot. Is your experience different? What would be rattling and why, I guess I'm wondering ...

Thanks,

Filippo[/quote]

I am never gonna live this down...[/quote]

No I'm asking seriously. Lots of folks do this. I assume there is a reason, and I've not encountered. Hence why I'm asking Mike. I'm just trying to understand. Not implying anything except my own ignorance!

Filippo[/quote]

oh, I thought I already said it was called out in the installation instructions by stew mac, not silicone per se but caulk, and being that I had an open tube of silicone at hand...

I just did it because I don't have much experience and the company I bought it from said to do it if you were worried about rattles. I don't know if I'm worried about rattles so I erred on the side of caution.

ok, my name was in that thead too, didn't make the distinction...

I do it because the instruction for stew Mac rods called for it. Have I expierenced this rattle on dual action truss rods? Yes! Its more of a buzz then an outright rattle. In have in my possession a Garrison guitar that has a removable dual action rod. The rod slides right out when totally relaxed. This guitar has a persistent buzz. I left the rod out and strung her up and the buzz disappeared. Put it back in and it reappears. The rod has a shrink tubing cover on it so its not that its a bare rod. So when I do them I use the caulk as per stew macs instructions....mike

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No even under tension there is that buzz. I actually tried putting an additional covering of some electrical shrink tubing I have but couldn't get the rod back in with it on. It was a little to thick since it's the black type made for electrical connections.

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Double acting truss rods will rattle (buzz). Getting a tight fit up is a good idea. Is that enough? Think of it this way: would you install barbless frets with a two-part tang, no glue, and expect to get good tone and sustain?

Silicone caulk in truss rod channels is not a finishing issue. I do a lot of finishing. I've seen a lot of issues. That's not one of them. I also do a lot of repairs. I fix a lot of buzzing double-action truss rods. To fix them, I inject silicone caulk in the truss rod cavity.

I never use "bathroom" caulk. Most silicone caulks are corrosive--they'll rust your truss rod as they cure (and rust the threads, and make a mess). Any decent industrial supply catalog has non-corrosive silicone caulks. The product I use for injecting into truss rod cavities is a non-corrosive, non-adhesive, low viscosity, catalysed silicone. It will flow in through a 16 gauge needle, set up without air, and not stick to truss rod threads.

I'm not impressed with most of the available double-acting rods. I've had to pull a few fingerboards to fix frozen rods. Looking at the welds on what's available, I'm surprised I haven't had to do that more often.

I like old school, Gibson style rods. (I also like the old Martin T-section reinforcements.) If you opt for a two element rod, get a good fit up, and bed the rod in a non-corrosive silicone caulk.

i just have a hard time thinking about what adding vibration dampening sound insulation(silicone, ie "rubber")does to the end product: good sounding music....no thanks!

Well I glued it back up last wknd, no silicone or caulk this time so I guess I'll see what happens. I left it clamped up for 24 hours, and didn't make any adjustment for 48. Everything seems to be holding fine.

Nyazzip, it was never flooded with silicone, it was just a couple dabs at the end blocks and a tiny bead down the length. It isn't meant to encase the truss rod, just act as a little cushion.

I don't have any problem with the tone or sustain on my first guitar, so I'm not worried about that.

I think from now on though I'll do what worked the first time and just adjust my clamping time. Thanks everyone.

Eric, I appreciate the comment.