Sunday, June 23, 2013

Refretting an acoustic guitar



OK folks. Hold on to your hats. Today we're going to refret an acoustic guitar.

Here's the patient:


And here's a close-up of the frets and fretboard. As you can see, some of the frets have worn quite badly. Additionally, there are some pretty serious divots in the rosewood board now too.


This is going to be one of our main tools for pulling the frets. It’s a fairly standard, and very cheap, end cutter. From now on I’ll be referring to it as a “fret puller”.

 
In order to help it get UNDER the frets, we’re going to grind/file the surface flat.



I’m resting the neck of the guitar on a huge rubber support, which I can easily move up and down so that it’s directly under whichever fret I’m pulling (or later on, replacing).


 
Before we actually start pulling the frets up, we’re going to heat them up with a soldering iron. The one I’m using is 60W with a flat tip on it. I’ll hold this near one end of the fret for about 30 seconds, moving it around a little, but keeping it towards that end.


Then we get the fret puller and get it under that end of the fret and slowly encourage it to pull away from the wood. Patience is a virtue at this stage; pull too fast and you’ll remove a chunk of wood while you’re at it. I’d generally still have the soldering iron touching the fret this whole time, by the way, but I had to put it down in order to take this photo.


We then start to work our way along the fret with the fret puller, keeping heat on the part we're about to pull up.




At the very end, take great care as this is a likely place for wood to be pulled out by accident.


And there we have it. One down, 19 (in this case) to go:


The same process is repeated for each fret.

Here it is half done:



And all done:


Before putting new frets on, we’re going to fix up the rosewood board itself, removing all those divots in the process. To do this, we’ll use a radiused sanding block (somewhat surprisingly, this guitar has a 12” radius, so we’ll stick with that), with fairly coarse sandpaper (in this case 150 grade, though anything up to 400 or so would probably work fine).


The fretboard is sanded down until the divots are removed completely (luckily there’s plenty of material to work with). Of course the same amount of material needs to be taken off all along the fretboard.



I should add that we've taped off the soundhole so that the guitar doesn't end up getting filled with rosewood dust. In fact, this is a good way to collect the dust, which, mixed with super glue, can make a very good filler in the future.


OK, the fretboard is now nicely sanded down:



Let's brush the dust out:


Before installing any frets, the fret slot edges are bevelled with a triangular file. This will help minimise the risk of any wood lifting when we hammer in the new frets (or widen the slots).


Now the fret installation begins. We’re using pre-radiused, pre-cut-to-length frets for this. We used this method before when refretting the Hofner Colorama here: http://diystrat.blogspot.com/2011/11/re-fretting-guitar-neck.html, and it worked out great there. However I think this will be the last time we use this method, as some of the frets at the upper end of this fretboard (farthest from the nut) were cut a bit shorter than I would’ve liked).

As it happens, the fret tang width is just a bit too much for the slots we already have on this guitar, so they're cut a bit wider with a hacksaw. Luckily the blade on this saw cuts the slots at the perfect width for these frets.


I’m lucky enough to be able to fit a ruler into the slots in order to check they are deep enough (in this case we need 2mm depth), but if you find yourself doing this and can’t fit a ruler in there, you can using something like an exacto knife blade marked at 2mm to test the depth instead.


OK, the slots are the right size now, so let’s hammer in the first fret. We’ll use a plastic-faced hammer for this, since it is less likely to damage the frets. First we hammer in one end:


Then we can either hammer in the other end before hammering in the middle, or we can just keep going along from one end to the other. I tend to do both ends first.

OK, that’s one fret done.


Halfway done:


The next few frets will go in the same as the others, but then we have to overcome a new problem, which is how to deal with the frets over the soundboard of the guitar. One solution I've seen is Frank Ford's lead ballast weight, which can be seen about halfway down here: http://www.frets.com/FretsPages/Luthier/Technique/Guitar/Frets/D35Refret/D35refret4.html

I figured I'd make a poor man's version, or rather, a man-that-doesn't-have-the-exact-same-resources' version. This dead blow hammer is filled with whatever the safe modern-day equivalent of lead shot is (for all I know, it actually is lead shot):


You may notice that I've cut about an inch off the end of it. That's so that I can get it inside the soundhole of the guitar, like so:


I then lift up the hammer (making sure the head of the hammer is under the fret I'm about to deal with), raising the guitar itself into the air, and hammer the new fret into place:


And finished:


Except of course we’re not finished at all. Now we have to bevel the edges of the frets so we don’t rip our hand to bits when we try to play the guitar.

You can do this one at a time:


Or several at a time:


Ending up with something like this:


After that, we need to level the frets, which is to say that we need to make sure the frets are all the same height.

First, let’s make sure the fretboard is level and, if necessary, adjust the truss rod to make it so:


Once it is, we colour in the frets with a Sharpie pen or similar:


Then we find something straight and flat (in this case, a spirit level that has been confirmed as really being dead straight/flat), and stick sandpaper to the bottom face:


This is then run along (not across) the fretboard, making sure that the same amount of attention is given across the width of the fretboard:


Once the black marks have disappeared, the frets should be level.

The next step isn't STRICTLY necessary, but I like to do it just in case I've inadvertently affected the radius of the frets.

We mark the frets again, and then run the radiused sanding block up and down a few times until all of the black is gone. This should be a very quick process.


Now we need to crown them, which is to say that we need to re-shape them so that they are rounded on the top.

So we mark them with a Sharpie again, and we file them to give them a kind of bevelled/rounded edge. You’ll notice that I am using fret protectors so that I don’t damage any of the wood while doing this.


What we want to end up with is a thin black line still showing along the centre of each fret. This way we know that we have not affected the overall height of any of them. 


Finally we run some steel wool up and down each fret to clean/polish/smooth them. We give each fret the same amount of attention so that if we are removing any material, at least it will be the same for each fret.


And the fret job is done:



The guitar is stringed up and any final adjustments are made:




Note that after doing this, I had to adjust the truss rod and change the height of the nut a little bit. This is to be expected, and in some cases you might even need to install a new nut. For more information on making a new nut, have a look here: http://diystrat.blogspot.com/2010/10/making-bone-nut-from-scratch.html

6 comments:

Jon said...

Love it every time you update. Keep up the great work, love all the projects.

stu said...

Thanks, Jon.

Brad Smith said...

nice work

jp said...

Great DIY site!

Thank you for sharing the love with a link back to Stratoblogster.

We're plugging you to our Facebook & Twitter friends!

Best!
jp
www.stratoblogster.com

stu said...

Thanks, jp. Much appreciated.

Love your blog!

stu said...

By the way, I notice you said on your Twitter feed that it's a German blog. Not quite sure where you got that (I'm an Irishman living in Taiwan). You can link directly to diystrat.blogspot.com. I think Blogger changes the suffix depending on which country you access it from.
Thanks again.