Affordable item for true sanding fretboard and neck base

[Philip Donovan]

Hello, its nice to be back at this great forum.

I'm well into building a Baritone Tele "type" guitar. Its a 28 5/8" scale with Ash body, Maple neck backboard and a pre-fretted fingerboard.
One of the next moves on this is to glue the fretboard onto the neck base as robustly and accurately as I can. As I understand, it is very important to have the joining surfaces as true and flat as possible. What I"m lacking is the means to sand the surfaces to a condition that is worthy of gluing/joining.

So far, the most affordable thing I've found (that I assume would work) are floating glass plates that can be found around $30-$50 or so, and are up to 24" long by 4-5" wide. Do you think that this is a viable means using sticky sandpaper? And should it be, is there a minimum thickness that ought to be used to avoid any flex while sanding?

I've made electric bodies before with good result but, this will be my first neck fabrication from scratch. I managed to form a maple neck base with truss channel that appears to have come out fairly well. I just need to be really prudent on going forward as I see my room for any mistakes will run out quickly.

Thanks for your input - if your know any good sources of items to accomplish the neck surface true sanding, I'm all ears!

Thanks again and best,

Phil Donovan

[Barry Daniels]

Rather than spending more for the glass, I would recommend using MDF. I have made many jigs from 3/4" MDF which is plenty stable and will create a very flat surface. If you attach pieces to form more of a structural shape like an angle or a C-channel it can become almost cast iron tool stable. For your application I would cut a piece large enough for the neck sanding and then another that creates a perpendicular plane and that piece could also serve for clamping to a vice. Join them with glue and small trianguler wooden brackets.

[Philip Donovan]

Barry,

Thank you for this recommendation. I've used 3/4" MDF for many things but never thought of this as a reliable "flat" but, I take confidence in your report that you've used it with good results. I will just need to understand better the best way to support the sized board with perpendicular under support.

Do you mean attach a piece of the same board 90 degrees to the top but thin enough to clamp? Flat to flat? Want to make sure I'm getting the picture.

Thank you Barry, great recommendation.

Best,
Phil D

[Barry Daniels]

Shape it like an extruded letter "T". The sanding surface would be the top of the T.

[Dan Smith]

MDF is very flat. I make various sized sanding boards.
My table saw has a large cast iron table that measures flat. I often stick sandpaper to it to flatten fretboards.

[Barry Daniels]

You could even use a countertop in your kitchen if it was straight and flat. The first tool acquisition in my career was a precision straightedge to know what is straight and what isn't.

[Philip Donovan]

Perhaps I shall saunter down to Woodcraft and see what they have for straight edges there. Most of the things there are fairly expensive but, they always appear to be of good quality.

Thank you,

Phil D.

[Philip Donovan]

Well it sure looks like the 3/4" MDF is up for the job of some decent flat sanding which I never would have thought was the case but, hearing from those who have proved that is proof for me! And thats good news.

Next step is prepping the ebony fingerboard and maple neck base for gluing. I will likely start a thread on seeing to it that the fretboard has been prepared for the neck before committing to glue and clamps.

This is for a 28 5/8ths Baritone electric. What I purchased from Stew Mac is their 34" scale pre-fretted ebony fingerboard for Fender basses. I understand that cutting the fingerboard at the 3rd fret begins the proper fret scaling for the 28 5/8" baritone that I'm making. I imagine leaving approximately 1/2" of wood behind the 3rd fret will be required for placing a nut with some extra to roll off into the tuner plane of the headstock.
I will gather the things for neck surface flattening and then start a thread on the details of forming the fingerboard as well as its placement concerning start and stop positioning.

Thanks for all this good info. Sure needed to hear this.
Best,

Phil D

[Philip Donovan]

Thought I would get back with a quick report.

I brought together some flats of 3/4" MDF about 24" long, 10" wide. Attached a couple of sheets of 180 grit with a very light spray of "Easy Tack" by Krylon. Its used for paper and to be re-positional and was enough to keep two sheets of sandpaper in place with no issues.

All seemed to go very well and from what I can tell, all is very flat and even, at least checked over with the limited "true" edge tools that I have.

While buying the sanding sheets, I caused a little trouble at Woodcraft in Woburn, Ma. (which hasn't been that difficult to do, historically). They seemed on board with the 180 grit for starters but then were a bit put off by my decision to use 320 as the final grit just before gluing the FB and neck base together. I referenced a thread from here at MIMF that stated that with aliphatic glues it was more of a chemical reaction in and between the woods that provided the holding strength and that the more surface-to-surface area was in contact, the more area to grab on to each other would be had. Also, that lower grits are good for using epoxy because both the epoxy has something to grab onto, and you are relying on the strength of the epoxy for the fastening strength. I admitted that I was merely parroting what I had heard from know long time builders at MIMF but, they all seemed convinced that 320 was too fine, and that they wouldn't go any higher than 220 with the aliphatic resin glues. I dunno. How could I.

So, time to get all set up for gluing clamping, and I am going to try to time this so that the pieces can be glued right after the fine sanding and good surface cleaning. But, for now, it was nice to see that the MDF appeared to do a more than adequate job of getting these pieces in form for a final sanding, cleaning and gluing.

Thank you again for your feedback here on this. Its all good news, and new news to me.
Best,
Phil D

[Barry Daniels]

Phil, One thing to get used to is that professionals in other trades (woodworking, finishing, etc.) all have opinions that need to be taken with a big grain of salt because their information may not apply to guitar building. We have very special considerations and can often ignore the "common knowledge".

But then again they were not wrong, 320 grit is finer than what you need for preparation of glue joints. 150 to 220 is plenty. However, don't worry about 320 grit messing up the joint. It will still stick just fine.

By the way, you mentioned surface cleaning before gluing. What is that going to consist of? Hopefully you are not going to wipe the wood with solvent. That is another of the "common knowledge" myths that we can ignore.

[Philip Donovan]

Hi Barry, thank you. I'm very glad you mentioned that as I was unsure of using Behkol to clean wipe as I've heard running around the internet.

I would be very happy to simply blow off the wood with some compressed air and/or wipe the surfaces down thoroughly with some nice 100% cotton fleece fabric I have. What is your suggestion?

Also, I haven't purchases new 220 or 320 so, I guess I don't have to lose any sleep over which one I get for final.

thank you,
Phil

[Philip Donovan]

Is tacky cloth something that can be used to clean something critical like the fingerboard/neck base join surface?

Reason I ask is that only once or twice in my life have I even handled tacky cloth, and it was so "tacky" that I had to wonder how the tack stuff wouldn't migrate to the surfaces it was cleaning. Of course, if it has been used by guitar builders for cleaning neck/fingerboard surfaces then my fears were certainly unfounded.

Thank you,
Phil

[Barry Daniels]

Tack cloths are good for cleaning off dust before finishing. It is overkill for glue joints. Just blow or brush them off. A tiny bit of dust will not hurt the joint.

Don't use solvent to clean the joint. The strongest wood joint will be surfaced by sanding or scraping within 15 minutes before applying glue. This has been proven from testing by military researchers who were researching techniques to make wooden airplane props during WWII.

[Philip Donovan]

Great info, and I do recall reading something about that testing during world war 2.

I"m going to work out a plan to be able to set the neck pieces with glue within 15 minutes of the final sanding and brush off, having all the necessary clamps at hand and perhaps small protruding sharp nails that have been aligned with holes in the fretboard for making sure the pieces do not roam during gluing and clamping. I've seen a few ideas on how to achieve that that make good sense. I will also need to see about anything that needs to be in place with the Stew Mac Hot Rod dual action truss rod. At this point, the flat tops of the brass rod termination blocks appear to be nearly flush with the neck bass surface. I think that suppose to be a good thing. I've heard somethings about applying RTV in certain locations to address any rattling that might otherwise occur.

So, a few more things to check into before final sanding, gluing and clamping.

Thanks again for your valuable contributions and I remain open to all suggestions going forward! Being that this is my first neck build, damage control is at a premium!

Phil