Official Luthiers Forum!
http://www-.luthiersforum.com/forum/

Fret slots - how deep?
http://www-.luthiersforum.com/forum/viewtopic.php?f=10101&t=41085		 Page 1 of 1
Author:  Spyder [ Thu Aug 08, 2013 10:22 am ]
Post subject:  Fret slots - how deep?
I'm getting ready to cut the fret slots in my first, and I am wondering how deep to go. Here is my plan:

1. square the blank
2. cut the slots
3. sand the back (glue side) to thickness
4. radius the top with sanding block
5. Install fret marker dots
6. trim to taper
7. glue to neck.

So, knowing the sanding block to radius the board will remove some material, what is the best way to get the depth right? I will use the Stew Mac fret slot miter box with their Japanese saw. That saw also has the stop which attaches to the side so i can deepen the slots if necessary after the radius.

I'd appreciate any thoughts on this!
Author:  Mike Baker [ Thu Aug 08, 2013 11:15 am ]
Post subject:  Re: Fret slots - how deep?
What I normally do is cut the slots close to half the depth of the board, radius, and use the depth stop to set the depth of cut on the saw just very slightly deeper than the height of the tang, and recut. It may sound like the initial cuts at half the depth of the board wouldn't require that, but I always have to cut at least a few slots deeper after the radius.
Oh, I forgot to mention: One of your steps is "sand the back to thickness". I would make sure my fretboard blank was at proper thickness before I did anything else. That's the first step in the process. JMHO.
Author:  Dave Stewart [ Thu Aug 08, 2013 11:43 am ]
Post subject:  Re: Fret slots - how deep?
I'd go 3,1,2 4,5,6,7
The slot needs to be deep enough so that the fret doesn't bottom out at the edges (after you've radiused). I use a very thin alum. gauge scored for the tang height PLUS what I loose at the edges for a 12" rad.
Author:  Spyder [ Thu Aug 08, 2013 12:22 pm ]
Post subject:  Re: Fret slots - how deep?
Thanks, I'll explain one thing. The reason I put thickness at step 3 is to hopefully save me some money in case I mess up, again. I already cut slots in two boards, but got a few out of position, and since the boards were already at thickness, they became scrap. I figure this way, if I mess up a couple of them, I will have plenty of stock to plane them down and start over.

Is this a viable option? I hope so, these are getting expensive. These are my first two guitars, and I have found very few things that I've been able to do once. Most things have had to be done two and sometimes three times. When I get these done, I plan to post a thread of what all I had to do.

Anyway, thanks to the Gibson raid, zircote fret board blanks doubled in price. So for these first two guitars, when you throw in shipping I now have around a hundred dollars worth of material in fret boards alone.
Author:  arie [ Thu Aug 08, 2013 1:46 pm ]
Post subject:  Re: Fret slots - how deep?
fwiw my process is:

1. rough to width and length +.25 or so
2. thickness to +.005 or so. mill, sand, and scrape glue side
3. radius to form and final thickness on fret side
4. mount to template and cut slots to +.010/.015 deeper then tang depth. trim to final length in the fixture.
5. mount to neck with pre-installed dowel pins and trim/contour fretboard sides to final
6. remove, fixture up, and drill and install position markers. sand/scrape flush
7. radius fret wire, cut, prep, and press em' in.
8. glue up to neck, work the frets, etc, etc, etc..

i use a fret slotting mitre box and ho'made and purchased templates, locating dowels inserted into the fretboard, and receiving holes for those dowels in the template and neck. and a fret press.
imo it's not necessary to cut the slots multiple times.


ah..i've been to your site. nice stuff! i can see though where templating and fixturing might be difficult with all of those unique instruments.
Author:  pthes [ Thu Aug 08, 2013 2:03 pm ]
Post subject:  Re: Fret slots - how deep?
I'd trim the board, radius and then do any inlay work. By trimming you have less material to sand. By inlaying after trimming you can see exactly what the result will be. You will also find that some people will do everything including fretting before gluing to the neck, others do all fret work after gluing. I've found that there is no "right way" but many "wrong ways" to do this. Being your first I suggest taking a scrap board as a practice fretboard and go through the steps to see if they make sense to you.
Author:  Tom West [ Thu Aug 08, 2013 2:04 pm ]
Post subject:  Re: Fret slots - how deep?
Just an additional bit of info. Once you are ready to fret it is nice to have a gauge to be sure you have enough depth. Take a 3" piece of fret wire, at the 1" point file a v notch the full depth of the tang, bend the wire at the v so that it looks like a hockey stick, file the barbs off the tang on the 1" section so that it easily slips into your fret slots. Use the gauge to make sure your wire will not bottom out on the tang in each of the slots especially at the ends.
Tom
Author:  DennisK [ Thu Aug 08, 2013 2:42 pm ]
Post subject:  Re: Fret slots - how deep?
If you need to practice, get yourself a 2x4. Plenty of thickness to plane and retry :) Once you get your process down, there should be very little chance of mistakes.

What are you using to locate the slots? Can that miter box use pre-made templates, or are you doing it by ruler? And if ruler, how accurate is yours? I wouldn't use anything coarser than 1/64". Here's an old post where I wrote up my marking/sawing process http://www.luthiersforum.com/forum/viewtopic.php?p=517584#p517584

As for slot depth, 1/8" should be good most of the time. Are you doing fingerboard binding? If not, then you need to consider the gap underneath the fret being visible from the side... although it's easy enough to fill with black epoxy or whatever on ebony boards. With binding, you can cut deeper, although it may have some impact on the total stiffness of the neck.

I level the fingerboard after gluing it to the neck, to eliminate any hump/dip at the neck-to-body transition. Then sand the radius. But you have to fret on the guitar in that case, which is more tricky than pressing on a bare fingerboard.
Author:  Spyder [ Thu Aug 08, 2013 7:05 pm ]
Post subject:  Re: Fret slots - how deep?
Thanks for the replies everyone. For my dulcimers, Stew Mac said on their site that their miter box won't handle material that thick. So, I made a legend stick, very carefully laid out with a high quality German made vernier caliper. For the guitars, I bought the miter box, but Stew Mac doesn't have a template that will fit it. So, my first attempt was to use paper templates, as discussed in another thread. I did the best i could, but when i held the two fret boards together, the slots didn't line up. Some were very close, but not good enough. So...

Since Stew Mac doesn't make a template for the scale I am using (24.500"), I made my own out of a piece of hard maple. I borrowed a 3 foot rule from a machinist friend, it reads in 64ths and is a Starrett, I believe. (Hate to give that thing back!) I used the rule, the maple board, a magnifying glass, and the best guess these bad eyes can give me to lay it out. After messing around with the miter box some, I think I finally figured out how to get it dialed in. This should work, and at least be repeatable, much closer than I can do by hand.

One thing I did notice on a test piece is the width of cut. I am using the Stew Mac Japanese pull saw for fret work, with their fret wire. Man, are those things tight! I haven't measured the slot width with feeler gauges, but it looks like either line to line or +/-.001 to the thickness of the tang, not counting the tabs. Is that normal? My test piece was very thin, and I almost had to bend it back to get the fret in the slot. I can definately see where adding the frets can cause a back bow in the board. How common is that?
Author:  DennisK [ Thu Aug 08, 2013 7:25 pm ]
Post subject:  Re: Fret slots - how deep?
Spyder wrote:
One thing I did notice on a test piece is the width of cut. I am using the Stew Mac Japanese pull saw for fret work, with their fret wire. Man, are those things tight! I haven't measured the slot width with feeler gauges, but it looks like either line to line or +/-.001 to the thickness of the tang, not counting the tabs. Is that normal? My test piece was very thin, and I almost had to bend it back to get the fret in the slot. I can definately see where adding the frets can cause a back bow in the board. How common is that?

That's how it is for me with this saw http://www.stewmac.com/shop/Tools/Special_tools_for_Fretting/Adjustable_Fret_Slotting_Saw.html. I kept forcing the frets in on the first several guitars, but finally came to grips with the fact that standard tang widths are just too much for that saw (you'd think they'd make them a perfect match...). So, I started grinding the barbs down with a dremel cutoff wheel, which works, but is time consuming, and dangerous getting my fingers so close to the wheel. So then I bought the fret barber tool, but haven't fretted another instrument since then so I can't give it a review yet.

Alternatively could have gone on a hunt for a perfect width saw, but StewMac's uke/mando fretwire seems to be even tighter than the guitar stuff, so I'd likely need a separate saw for that... better to just have a tool to custom fit to a single saw. Plus having the slots on the narrow side to begin with means more refrettings before worrying about them getting worn too wide.
Author:  Spyder [ Thu Aug 08, 2013 10:47 pm ]
Post subject:  Re: Fret slots - how deep?
Dennis,

On my dulcimers, as I mentioned I have been cutting the slots by hand. I start with a score line from a marking knife, make a cut with a .010" kerf razor saw, then widen the cut with a veneer saw. I bought this little saw at Woodcraft, and it has just the right kerf for dulcimer fret wire. Drives in nice and tight, plenty strong to hold without glue (so far,) and just seems to work well.

So I have some more investigating to do. It may be better to cut the slots with the SM saw, then give them a swipe or two with the veneer saw. I need to check the widths of the fret wires, I get the dulcimer wire from a different supplier.

As tight as these look with the SM saw, I am a bit leery that I will be able to drive them in flush without causing some damage.

here is a pic of the veneer saw:
Author:  Michael.N. [ Fri Aug 09, 2013 1:58 am ]
Post subject:  Re: Fret slots - how deep?
You shouldn't have to mess with the slots. If the Japanese saw is giving the wrong kerf then it's not fit for the purpose. Either set it (if possible on a Japanese saw) or buy a saw that gives the correct kerf. The veritas cuts at 0.7 mm's - if that is too wide you can carefully stone each side until it gives the correct kerf. You are looking for a saw with thin gauge steel - 0.5 mm's. That will allow a bit of set and no binding in the cut. One of the larger Zona saws could be suitable if you can set it. As it is there isn't enough set. I'm going to buy one and try set it with a punch. But it's a cheap enough saw to mess about with and learning to set and sharpen hand saws is a very useful skill to have. I sharpened my 24 TPI Zona saw only last week. Just stuck a file in the gullets and filed straight across, one stroke. None of that skipping one tooth. Amazing how well it cut. Before I sharpened it the Zona was a throwaway saw. I'll easily get another two or three sharpenings out of it before I really mess the teeth up. Then I'll throw it away. Took me 5 minutes to sharpen it.
Cutting fret slots with a handsaw is all about the saw plate gauge, correct kerf and SHARP!!! Years ago I bought the LMI (I think it's the same as SM). It was a very frustrating experience. As I measure it the gauge is the same as the Veritas (should be OK). Nothing wrong with the steel. Had to be due to how it was sharpened or rather how dull it came when I bought it. Cuts perfectly fine now.
Author:  Colin North [ Fri Aug 09, 2013 2:19 am ]
Post subject:  Re: Fret slots - how deep?
I had a similar experience with the SM fret saw (English one)
Comes blunt, and found the handle awkward.
The saw kept tended to tilt off 90 degrees when trying to cut the radiused fretboard slots to depth, and jumping out of the slot, marring the slot edges. Very frustrating.
Converted handle to pistol grip, sharpened it, and it's like a different saw altogether. A pleasure to use
Author:  Michael.N. [ Fri Aug 09, 2013 2:29 am ]
Post subject:  Re: Fret slots - how deep?
Well there's nothing wrong with the handle, it's just your typical Gents saw type. I get on fine with them. It's the sharpening that is the problem. Compare it with how sharp the Veritas comes and the difference is light years. Nothing intrinsically special about the Veritas steel or bad about the Flinn Steel. It's all in the sharpening.
Author:  cphanna [ Fri Aug 09, 2013 9:17 am ]
Post subject:  Re: Fret slots - how deep?
Phil, regarding your two "scrap" fingerboards: If they haven't been tapered or radiused yet, I'm pretty sure you could fill the slots, turn the boards over and swap them end-for-end. Turning them over obviously gives you a new slotting surface. Turning them end-for-end locates the new slots out of alignment with the filled slots. Binding would then completely hide the fill. You probably wouldn't do this on a guitar for a customer, but I see no problem with using those boards on your personal instruments. I've seen this repair demonstrated here on the forum a few years ago. I can't remember the fill material, but I believe it was veneer strips and epoxy.
Patrick
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/