I wish the Thomas Ginex people would make a strong, thin metal, radius block that would fit under the strings and have just a small over hang on both sides of the neck....that way I could us my fingers to keep it tracking straight up the neck. I sent them an email but they never responded. Could use it to sand the radius into the fingerboard and dress the frets under the tension of the strings. I have a couple Bedell BDD-M-15 acoustics that have very thin tops and they get a little hump at the body. If anyone knows of a thin, yet solid metal radius block that would work with the thomas ginex system then let me know.....I'd buy it if it wasn't too expensive. It has to be able to fit under their raised string nut. Maybe a little thicker then their sanding block.
Our start point with getting necks in order is to dress the frets with a 20inch Aluminium (Alooomnumb, if you are of the U.S. persuasion and missed a lot of school) radius caul of which we have 6 all with a specific radius.
This ensures that we have a perfect radius on the fret top and that the #1 fret is now indexed/related to the #22/24 fret. After doing that the frets are crowned and the process repeated. This is all done with the neck jigged flat as I don't use flat necks in service (ie: non-relieved necks under string tension). This basic start procedure will generally fix most problems or get them in range of final tweaking under tension.
I also use a little compounding and drop away as part of our standard manufacture/repair profile.
As for problem necks with a hump here and a bump there, they usually goes away after the first level and those that don't get a bit of specific attention after the neck is re-read under tension.
This method of finish>> sanding frets parallel to the string lie/lengthwize with coarse abrasive paper is death to string bending and can be seen quite clearly under magnification - we cross finish frets with diamond files and various grades of micromesh to ensure minimum resistance to string movement sideways.
However, this takes into account that we are a viable business above all else and need to achieve the highest quality consistent results in a realistic timeframe for demanding customers, to stay in business and make money. If you have a lot of time you can do OK with this system as well, but these are two different things.
The Egyptians would have used use trucks, cranes and laser levels if they had them.
Makes sense....you're going back through and fixng any hump problem that shows up under tension by addressing it with a spot radiusing. It sounds like your doing a final fix by leveling/radius the problem frets....not the fretboard. The fretboard is close so it's just a tweek. It seems like it would be easier and more accurate to do the fretboard radius under tension instead of the frets... but I understand what your saying.
Hi David, Yep, That's our regime for repair and refurbish without refretting. For refretting we use the same long radius cauls and redo the geometry in our favor before proceeding.
Getting some extra new fret slot depth and making the slots consistent before refretting (CA glued, everytime) will generally assist in normalizing any previous maladies. Having the fretboard surface fully related from end to end and then dialing in a bit of dropaway to take care of string choke with low actions and get rid of rising tongue effects also help the playability.
The thing that I have found over the years is that accuracy of a couple/ten of thou' in the initial machining and leveling does wonders for the end result. Our new boards are cut with the attached system and final finished with the long cauls - we can now fret very accurately and with our pre-radiused Stainless Steel frets we can go straight to playing with minimal touch ups - most crowns still with their OEM finish. This is the sort of accuracy that modern playing demands.
Bit of a ramble I know, but it breaks out the concept of what modern accuracy can be achieved.
Well, as I see it, he length and width of the plate that comes with the T.G. kit are two of the problems. The plate has no radius, which to me, means that it's too wide as a flat surfacing tool. Besides that, it doesn't span enough frets to not potentially leave "rockers".
This leaves the user with the task of somehow maintaining the radius evenly across the width of the frets and along the length of the neck while leveling the frets without leaving "rockers" using a plate, running under the strings, that only spans a few frets so must be held as parallel to the surface of the neck as it moves over the length while being rocked from side to side to maintain the radius in accurate fashion. This kit doesn't require the user to do this once either but insteads requires this to do done three times. all of that for a "simple" fret dressing which doesn't even start to address the added fall off that may needed on the fingerboard extension. That just seems like a lot to ask of anyone, much less someone that has probably never done something like this before.
I'm glad that you feel you get good results with this kit. It would be awful if you has used this approach on your nice guitars and found that it hosed them up royally. I'll just stick with what I know and trust.
David here's an older thread with an encyclopedic coverage of neck jigs w/updates over the past 6 years that may help: http://fretsnet.ning.com/forum/topics/are-neck-jigs-necessary
I've used Ron Frazier's (via Martin) method of fret leveling described in this thread since reading it. This has worked well for me on any frets I've leveled/dressed since and is good, fast and cheap. If the customer wants super precision I offer them a $300 fret leveling svc. Everyone has been happy with my $125 fret leveling service. ;')
Thanks....wish he had a picture.
I think I'm going to use the Thomas ginex with a long file to dress the frets when I refret next time. I can't fit the radius block under the strings so will have to do it without tension or make something.
No picture but here's my process:
Verify that the strings on the guitar are the type and gauge the owner uses and the most common tuning used.
Adjust the neck as close as feasible under string tension
Remove the strings and place a support under the nut and tail block leaving the upper bout unsupported.
Tape a 5lb weight (I use small vinyl covered dumbbells) to each side of the upper bout leaving room to work on the frets.
Place a support under the neck block at that height to support it while leveling.
If I need to be more precise I check the neck w/a straight edge and measure the gap under string tension and mark the fret at the highest gap. Then after adding the weight w/o strings, check the neck w/a straight edge and measure the gap at the marked fret to confirm I'm not too far out. I have a whole set of dumbbells and mix and match if needed to get it dead on.
What's the upper bout? Tape a 5lb weight (I use small vinyl covered dumbbells) to each side of the upper bout leaving room to work on the frets.
Between the waist and the shoulders or on an electric, the top 1/3 of the body. In this instance, I get the weight as close as I can to the shoulders on each side of the fretboard extension. You could also make up some skinny sandbags/lead shot bags, mortar bags, etc and feed them in the soundhole all the way forward. I just happened to have the weights.