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I picked up a circa 1987 vintage Sigma dreadnought this weekend.

Good news: the body is in pretty decent shape, and the finish only had a few minor dings.

Bad news: the truss rod is broken and someone did an abysmal refret job. The frets are finished cleanly and level, but it looks like someone just ripped the old ones out. There was chipout on most of the frets that was glued back into place, but it was not glued cleanly or flush. I painstakingly sanded these flush with fine sand paper and steel wool to diminish the evidence.

Sorry, my tablet camera is not good enough to show the details.

I haven't done to much research on this particular model yet, but does anyone know if the StewMac low profile two-way rod will work. I'm a little hesitant to replace it with the standard one-way Martin square truss rod, although I'm sure it would be fine.



Also, any ideas about the original finishing material or glues used.

Thanks in advanced.

Glenn

Sorry, that's DM2

If you are willing to plug the existing truss rod channel and cut a new one then almost any truss rod should work. I would wait until I had it open to decide what parts to order.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I'm open to just about anything, but since this isn't a valuable instrument, I prefer the least effort to make it playable.

I'm also a little concerned about the finish on the neck built up over the fretboard. Should I score that line?

The body needs some minor touch up, but without knowing the original finish material, matching is going to be difficult. Going back to Google for answers.

Glenn

Looks like these were finished with catalyzed poly. Any tips for touch ups? I'm familiar with shellac and nitrocellulose, but hated polyurethane the few times I've used it.

The back had some scratches that were too deep to buff out, so I will have to lightly wet sand it.

There's a small chip in the finish on the back near the center/lower binding. The finish is quite thick - perhaps 0.5mm.

Considering the thickness of the finish and the nature of the truss rod replacement, I'm considering stripping the poly finish off the back, sides and neck. There'll be no way to match the finish once I break the fretboard glue line.

Maybe the top too. I think it's a solid.

I know it's going to be a lot of work and It's not a valuable guitar, but I think a lighter finish will sound better too.

Glenn


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I find that PPG DCU2021 which is an auto refinish clear to work well for repair and touch up of poly guitar finishes. If you carefully score the old finish with a hot exacto knife along the bottom of the FB before removal the edge of the old finish will not be very noticeable.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks, B. I'll look into it. I'm still undecided on the touch up vs refinish. My air compressor died last year, so I can't really spray at the moment. I was planning on hand refinishing or drop filling touch up.


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I tried removing the finish with heat, but no matter how hot I got it, it didn't want to come up. Rather than spending endless hours peeling, I took the sander to it. Look what I found 20 minutes later:



I accidentally sanded through the veneer on the upper bout edge. Would gluing a thin Mahogany shaving and then leveling likely leave visible glue lines?

Glenn


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You could try cutting out a section of veneer and laying in a new one at the damaged area, but you are likely to sand through again when you level sand the patch. And grain match will determine just how good it will look. I would camouflage the area with a bit of stain and let it go as these thgings have a tendency to go from bad to worse rather quickly.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

dang laminated sides! Sanded through the veneer again.

Now it's either make new sides or glue veneer. Either way, I'll have to redo the bindings.

Not sure it's worth the effort.

Grr...good lesson I guess.


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This thing keeps getting better and better!

Got the fretboard off successfully. Turns out the truss rod wasn't actually broken - the nut was stripped. Had I tried to pull it out, I would have discovered that it was an easy fix (new nut).

I got some mahogany veneer to patch over the sides, but I wanted to remove the neck to get a clean veneer joint. However the neck joint is apparently one of those Asian mysteries: the doweled-Y.

I completely stripped the neck, including the headstock. I'll put a nice veneer on it.

I expect to redo the binding. Hopefully the perfling will stay intact.

I think I will shellac the neck and shelf it to work on my pair of classicals for now.

That particular line of Sigma guitars was never intended to be repaired.

Glenn