Hotrod Your Guitar - Lower the Action




Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founde...

Why did Bryan Adam's fingers bleed in the summer of '69?
Because every fricking guitar you can get near has a PAINFULLY HIGH ACTION (height of strings)

Guitars with sweet low actions do exist, but there's already a dude/ette with no biceps playing it 24 hours a day and going without food.
Here's how to lower the action of your own guitar.
It'll feel so good you'll play it instead of eating/bathing/sleeping.
There won't be anything left of you but bad posture and enough hair to comb over your face.

The cheap ones start out too high. Old ones get that way over time from the tension of the strings.
For examples of both kinds, I'll be dropping the action on this Chinese-made "Backpacker guitar" that cost me a penny brand new (plus $24.99 shipping on ebay) and also an original Martin Backpacker.

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Step 1: Go Nuts on the Nut

You probably want your strings as low as they can be without buzzing while you play.
That depends a lot on how you play. If you play hard you'll need the strings to be higher or they'll buzz.
If you play slide or bottleneck guitar, you'll want the action higher still.
In fact, if you use the slide all the time, you don't really have to use the frets, and there's no such thing as an action that's too high. Keep that in mind when you get a free guitar with a really bent neck.

Regardless of your situation, the best way is to find a guitar you like playing, and measure the action
If you only have access to the one you're working on, just whittle down the notches in the nut and bridge until you like how low it is. If you wittle too low you can put a drop of superglue in the notch and let it dry. Or put a piece of paper under the string.

If your neck is straight and your fingerboard is flat, you'll be able to put them lower.

Here I am whittling down the nut notch on the penny guitar. You can use a triangular file if you have one.
Play with the string and sight down it. The nut notch should be as deep as if there were another fret there holding up the string. In other words the string height differece between the nut and first fret should be the same as the difference between the first two frets.

Step 2: Take It to the Bridge

Here I am whittling notches in the bridge. I could have sanded down the bottom of the bridge instead, but the manufacturer made a mistake and the strings are too close together. I'm cutting new notches. When I'm done the array of strings will be 2" wide at the bridge.

The second photo shows the bridge after some wittling then playing then whittling...

The heavier strings usually need to be a little higher than the thin ones.

Step 3: Straight - Edge Guitar

If you want to be more precise than just eyeballing, you can find a totally straight bar, such as a a carpenter's level or this extrusion I stole from the bureau of standards.
Lay it on the fingerboard and see where it lines up with the bridge. Then eyeball that.
You could measure it also if you're confident you know how high you want the strings to be at that point.

If removing the saddle completely isn' t enough, you can sand down the bridge a bit.
If that's not enough you have two options: Either do an operation called "re-setting the neck" which is tricky. Or you can call it a "slide guitar" and suddenly a high action is a virtue.

Step 4: Flatten the Fingerboard

Some guitars have a steel rod down the neck that can be adjusted if the neck is bent.
Usually the bolt head end is concealed at the by a little plate at the "carpal-tunnel" point near the tuning pegs.
Neither of these guitars has one and both have pretty straight necks, so look for that truss-rod info elsewhere. We're just going to take a neck that's already pretty straight and flatten the fingerboard a little.

Over time some frets get worn down more than others. Various other mishaps can make the frets uneven. To even out small irregularities put some sandpaper around your flat bar and sand the frets a little bit. You'd rather have the frets be round than flat, so don't sand too much.
And don't worry so much.

Step 5: Lowering a Glued-on Bridge

The Martin has a glued-on style bridge. The white strip that props up the strings is called the "saddle".
It's supposed to just lift out, but it's stuck, probably from years of drool.

Most stuff gets a little softer when you heat it up, so I tried warming it with the heat gun. Not too much, the guitar doesn't need to be scorched. Insert pun here about "scorching licks".

Step 6: And Yank

Sure enough, after some wiggling it pulled right out.
I scraped off some coffee-drool composition and put it back in to draw a reference line.

Step 7: Draw a Reference Line

Draw a line at bridge level on the saddle. That'll make it easier to keep track of how much you're sanding off it.

Step 8: Sand Down the Saddle

Sand it down as far as you think is good. Check it now and then by putting it back in the bridge.
I thought this guitar was high due to age, but according to web see-say, a lot of them came from the factory that way. Apparently Martin also makes saddles of various heights, in case you see white strips of bone rattling around in your guitar case and don't know what they are.

That's it! Re-string your guitar and it's ready to play!

Step 9: Add a Strap

The one penny guitar came with no place to attach a strap. So i drilled an undersized hole and screwed in a brass buttonhead machine screw with the head protruding to tie a strap to.

Step 10: Rock Out!

All right! Man, that's a tasty low action.
It's time to play "Louie Louie" like it's never/always been played before!!

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    42 Discussions


    2 years ago

    WARNING. This guy went on a journey to transform an ultra-cheap oddball guitar without a truss rod into something more playable, and it was entertaining to read & possibly useful for anybody else trying to work on an ultra-cheap guitar like this one. But I strongly recommend against anybody with an electric guitar or a regular acoustic guitar following ANY of the advice in this article, because every single one of these steps could very easily ruin your instrument. Many, many guitars have adjustable saddle height, and this is by far the easiest and safest way to adjust the action on a guitar. And almost all guitars have a truss rod through the neck that can be used to adjust the bow of the neck, which also affects the action, but even adjusting the truss rod is something that you can easily break your guitar doing if you're inexperienced. Doing anything to a guitar that produces sawdust... drilling holes, filing down the nut or the saddle... should really only be performed by an experienced guitar technician. The photographs of heavy weights placed on the guitar to straighten out its neck sent chills down my spine! Only total junk instruments, like the guitar in this article, should be treated like that.

    1 reply

    Reply 2 years ago

    Not sure if you actually read the article as he was using a straight edge to sand down the frets, and not using a weight to straighten the neck. I'm guessing you didn't read and then advised people not to follow it?


    7 years ago on Introduction

    how much is the cheap chineese made backpacker? i was looking into a backpacker, but at 175 used..... yeah....


    7 years ago on Introduction

    thanks, useful article and will give me confidence to tamper with my son' s cheapie guitar.
    however i own a martin backpacker and wouldn' t touch the action. use (elixir) 47 to 10 strings and it' s just fine. recommended to have those strings as no truss rod. low action and heavier strings risks deforming the neck.
    cheers and ta


    7 years ago on Introduction

    Considering experienced guitar techs take tons of practice and many many attempts learning how to properly slot a nut, I would highly un-advise doing this on anything BUT a penny guitar until you know what you are doing.


    8 years ago on Introduction

    Are people getting hired to write fake reviews of this thing?


    8 years ago on Introduction

    or if youre using an electric guitar ( usually a nice one that you dont want to ruin by cutting the bone made nut) you can turn the knobs on the 2nd part of the bridge and it will lower them and not worry about getting any buzz


    9 years ago on Introduction

     My guitar (electric) was only £190 (or about 275 Dollars if you're american) and It has a really low action, but doesn't seem to buzz =P.


    9 years ago on Step 1

    what i did to lower the action on the nut is actually grind it down with the string itself like a saw, then you know it will fit the string perfectly!


    9 years ago on Introduction

    Good maybe I'll be able to learn too play that  cheap acoustic I got off of ebay. Strings are killer high!

    this instuctable was good right up until you got the green suite on. now im just confused.


    9 years ago on Introduction

    Good instuctable, but I wouldn't really recommend whittling down the nut or bridge, it is pretty likely to cause tuning problems


    10 years ago on Introduction

    Thanks to you, my cheap old guitar is now easy playable. Good Instructable !!!


    11 years ago on Introduction

    thanks i play ukulele and have one with extremely low action and love it. unfortunately I recently smashed a $15 ukulele because it had and unplayably high action


    11 years ago on Introduction

    I have an old Epiphone archtop (1933 )that either has a non-adjustable trussrod or was made before trussrods. It had a big bow when I got it. I hung it from the wall by the headstock primarily as a decoration with the strings tuned down and low and behold the neck eventually straightened out! I keep it tuned down for slide so it won't bow again.

    1 reply

    Reply 11 years ago on Introduction

    if you want to play it more often, try lighter gauge strings on it if it has heavier ones on it. Lighter strings, less tension, less bow.