Straightening Acoustic Neck

[Mr. Preston Swift]

heyo

i recently obtained an acoustic guitar with a bolt on neck

First of all the neck had a massive bend in it which i fixed with an iron

now the neck is perfectly straight, but when it was put on the guitar (bolted on)

it turned out that it was mostly neck angle

how would i go about fixing this?

[Acousticraft]

Are you saying the neck was bowed but gave it some neck angle. Now you have straightened it there is no neck angle?

Does it not have a adjustable truss rod?

My thought would be to make up a thin tapered shim to put between the body and neck heel to create some neck angle.

I have found you always need more neck angle than needed on an acoustic due to the distortion of the body by string tension which pulls down at the sound hole and tilts the bridge forward.

[Mr. Preston Swift]

Are you saying the neck was bowed but gave it some neck angle. Now you have straightened it there is no neck angle?

Does it not have a adjustable truss rod?

My thought would be to make up a thin tapered shim to put between the body and neck heel to create some neck angle.

I have found you always need more neck angle than needed on an acoustic due to the distortion of the body by string tension which pulls down at the sound hole and tilts the bridge forward.

the neck was bowed and straightened

it's old and lost it's angle long ago from what i can tell

it has a non-adjustable truss rod

it also has a sort of metal saddle so I can't really file it down

[Acousticraft]

You will need to put packers under the top edge of the neck, under fingerboard, to see what thickness a tapered shim would need to be.

I guess without a neck angle it has a high action?

The easiest way to check the action is to put on the High and low E strings and pack the top edge of the neck until it has an acceptable action of approximately 2mm between string and fret for high E and 3mm for low E at the twelfth fret. Once you have worked out the needed thickness of a shim you can make a pattern of the neck heel and make a wooden shim and taper it down at the bottom of the heel.

Hope this helps but without seeing exactly what is involved I may be guessing here.

[fryovanni]

Attach the neck(no shims). Place a straight edge on the frets and confirm the neck is straight, then with the straight edge on the frets see where the straight edge aligns with the bridge(a picture of this would be handy). String it up and see how much relief is generated. If the body meets the neck at the 14th fret hold the string down at 1 and and 14 then test the relief at 7th. If the neck meets the body at the 12th hold the string down at 1 and 12 again check at 7. This will give you an idea as to how the neck is going to perform under tension(I am not sure how you adjusted the neck with an iron(assuming household clothes iron)). After you know how much relief you have. Hold the strings down at the third fret and check your string clearance at the first fret. Finally with the guitar tuned check your clearance at the 12th fret. Any extra pictures would be helpful.

So if you can; give us the pic/pics or indication of where the fret plane would meet the bridge/saddle. Measurement for relief, measure for clearance at 1st, clearance at 12th. (measurements will be most helpful if you can get them accurately(feller gauges work well) and measure to the thousandth of an in(ie.. say .005" clearance at 1st fret).

Peace,Rich

P.S. Also confirm if the fretboard is flat or tapered. Some fretboards are tapered as opposed to angling the neck. If you can inspect the top when it is tuned and look for distortion that may be happening(sinking between the bridge and neck, or maybe lifting behind the bridge). That info would be handy to know.

[Mr. Preston Swift]

sorry i didn't get back to you right away

the neck is perfectly straight and fretboard is flat and mets the body at the 12th fret (it is an acoustic not a classical)

as far as i can tell there is no distortion between the neck and the body and neck

the bridge is fine and isn't lifting

the action is about a half an inch off the neck at the end of the neck which leads me to belive that the neck angle is wrong

also the neck is bolted on like an electric would be

I will get back to you guys with pictures in the next day or too

thanks so far