To glue or not to glue?

[Dave Sparrow]

Hi everyone

I guess that this subject has already been discussed but I couldn't find a clear answer on here so I thought that I would take a punt and ask for your opinions on installing two way truss rods.

I'm replacing a broken rod (like this)

and wanted to  know if you guys glued in a cover fillet and if so, do you glue it to the flat bar?  It seems that there are 3 (or 4?) different ways to fit these. 

• LMI suggest that no filler strip is required yet they have a link on their website where Rob O'Brien demonstrates how to fit them but installs a fillet glues the fillet to the flat bar with epoxy.

• My supplier (WD Music) again say no fillet but to set the rod about 0.010 - 0.015" below the top of the channel and suggest loosely wrapping in plumbers tape (PTFE) to protect against glue and rattle.

• The original rod in the neck I have had a fillet glued to the flat bar but not along the full length of the channel, only the middle two quarters.

What do you all recon?

(confused) Dave

[Jeff Highland]

If there is a space above the rod, it need to be filled or you will have the potential for rattle and a lot of wasted motion before the rod starts having an effect.

[Dave Sparrow]

Thanks for your reply Jeff.  I can see that but would you glue the fillet to the top of the rod as Rob O'Brien suggests and as the broken rod in the neck in question was?

[Jeff Highland]

Yes  If I use a fillet I glue it so that it is able to be levelled and does not fall out of place during fretboard installation

[Dave Sparrow]

Sorry to be pedantic but I need to know if you would apply glue to the bottom of the fillet so that it is glued to the top of the truss rod as Rob O'Brien does? He says, abrade top bar surface to form a key, glue 3 faces of the fillet with epoxy (2 sides and the bottom) and depress slightly to get a better glue fit.

I hope this link works because it will help me to explain.

https://www.youtube.com/watch?v=tLY3iN1Atn4

[Jeff Highland]

The integrity of the glue joint is irrelevant IMO (ex engineer )  there is no real load on the glueline

The fillet is just filling a gap and stopping ingress of glue when gluing on the fretboard.

Titebond or epoxy would both work fine -glue to the flat bar

[Ian Pender]

For what it's worth, I do not glue my fillet strips to the rod. I'm assuming O'Brien does so to minimize the risk of rattle when using a double action rod, but if you use plummers tape and clamp the fillet strip down tight, you shouldn't have a problem. At least, I haven't. Personally, I'd be wary about getting too much glue or epoxy in the truss rod route and fouling things up, but if it works for Robert O'Brien, I guess it's not a problem.

[Dave Sparrow]

Thanks very much Ian.  I hope that this thread will help others in future.