Repairing a high humidity affected guitar

Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

I made this guitar for a grandson in 2016. It has lived in India ever since. 6 years in a very high humidity with hot temperatures caused extreme warpage to the neck.

The body is ambrosia maple. Top is sinker redwood.

I received the guitar this weekend when my daughter and grandkids came to the USA for a summer visit.

Surprisingly the top does not appear to have damage or deformation other than the bridge is sitting higher because the top dome has increased slightly.....but the bridge is not rotated forward. A good surprise.
Also the top under the fretboard extension has not caved in....another surprise.

So I started the repairs today. The plan was to remove the neck and evaluate. It's a bolt on M & T neck and the fretboard extension is not glued down. So easy removal.

The tenon bolts are rusted but came out okay. Guess I should be using stainless bolts and barrel nuts for India guitars.

The neck is crazy warped. I put a Gotoh double action truss rod in this neck and it would not affect the warp.
So, the fretboard had to come off. That took awhile, clothes iron heat and thin putty knife. It finally came off with very little damage to the neck.

Okay so I had to clean off and flatted the bottom of the fretboard. The neck surface was not flat....low in the center (warped?). I removed the truss rod which also had some rust. I scraped and sanded until I had this surface flat again.
Now I checked the mating surfaces for the neck heel and the fretboard extension and the were not flat so I remedied those areas and they are now flat. I checked my neck angle and it's at 88 degrees which is where I place mine.

So I installed a new truss rod. A one way same style as the Gotoh. Shorter and lighter weight. Should be an improvement.
I've glued the fretboard back onto the neck and it is now flat. I had to floss the heel a bit to bring it back into the correct angle but that is done.

I will redress the frets after the neck is reattached for the final time. My bridge is too tall by about an 1/8" so I'll shave that down. Not to worry I make my bridges 7/16" high so I can afford to take some off and my saddle slot will still be plenty deep.

I did a French polish on this one and I'll need to do touch ups on the body, top and neck after reshaping the neck where the fretboard is reattached.
Nice that I'm not dealing with lacquer on this one so the "refinishing" will be easy.
It had plenty of dings and scratches, especially on the top that I will just leave. This guitar will be put to use again...heavy use by a 17 year old who plays alot and is probably not super careful. 😀
I plan to return it to him in a couple of weeks.

I'll post again with more pics as this progresses.

Kevin
You do not have the required permissions to view the files attached to this post.
Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

More pics
You do not have the required permissions to view the files attached to this post.
Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

More pics
You do not have the required permissions to view the files attached to this post.
Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

More pics
You do not have the required permissions to view the files attached to this post.
Diane Kauffmds
Posts: 2846
Joined: Sun Mar 09, 2014 8:13 pm

Re: Repairing a high humidity affected guitar

Post by Diane Kauffmds »

That's a nice job Kevin. If the guitar is going back to India I would suggest gluing at the same humidity in which it'll be used and stored, and maintain that humidity with a humipak. But i figure it needs 50%.

Boveda makes 49% packs for guitars. But they also make higher humidity packs. The humidity packs work both ways, releasing moisture or absorbing it as needed. I'm not sure of their limits.

At least in a high humidity, he wouldn't have to worry about the humipak drying out. Usually that's how they wear out. But he could get a couple and refrigerate them if they become too saturated, keeping a couple in the case. Refrigeration will dry them back out. Just don't dry it completely out.

They're only $47 for 12 packs. You can buy fewer.

Boveda Wooden Music Instruments - 49% RH 2-Way Humidity Control - Size 70 For Wooden Instruments – Protects All Wood Instruments For Optimal Sound – Prevents Cracking & Warping Of Guitars – 12 Count https://a.co/d/gVo5qO1
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

Thanks Diane. Dehumidifier is a good idea but not practical for my India family especially the 17 year old grandson. I don't think he'd stick to it.

I refined the neck fit. Cleaned up the fretboard to neck joint and blended in the neck shaft curve. Mounted the neck. The fretboard extension lays nicely on the top.
A straight edge on the fretboard comes in about a 1/16" below the bridge at the center saddle location so I took out the block plane and took it down that amount. Now the straight edge just clears the bridge. I'm figuring I'll end up with about a 3/16" saddle height or a smidgen less. Saddle slot is 1/4" deep so I'm in good shape.

Next with the neck mounted I'll level and dress the frets. They look pretty flat with a slight drop off at the extension.....just what we want right?
I'll post some pics of this process tomorrow.

Once that's done I'll start the French polish repairs which may entail going over the whole guitar. I'll see.
Diane Kauffmds
Posts: 2846
Joined: Sun Mar 09, 2014 8:13 pm

Re: Repairing a high humidity affected guitar

Post by Diane Kauffmds »

You're right. A 17 year old wouldn't use it. Short of starting with a high humidity shop, with the wood acclimated and gluing at high humidity, I can't think of anything you can do. Obviously, this can't be done. Your replies look great.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

Got the fret work done yesterday. Took some off the top of the bridge which is now 7/16" tall.
Straight edge just clears the bridge.

Started French polishing. I will be going over the whole guitar but leaving dents and scratches....which are mostly on the top. So it will keep its used character but look refreshed with a new shine, I hope. It's been many years since I did this FP thing
Kevin Sjostrand
Posts: 3254
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Repairing a high humidity affected guitar

Post by Kevin Sjostrand »

Well I believe I'm leaving this where I have it now
I tried to refresh the shellac finish alla French polish.
Hmmm it's been 6 years since I've done it. This didn't go the way I'd have liked but I think it looks better than it was.
Shiney at least. The pick guard was peeling up so I pulled it, cleaned off the adhesive, applied new 3M transfer adhesive and restuck it.
I cleaned up the nut and saddle. I had too much bone above the nut slots so I sanded and reshaped so the slot depths are now a little more than half the string diameter as they should have been. The saddle fit too tight in the slot so I fixed that. It looks like I'll have a low action with strings on like 4/64th and 3/64ths at the 10th fret. Hoping there will be no buzzing.
So the finish is still a little soft so will wait till Saturday to install a JJB Electronics Prestige 330 passive transducer pickup and string it up.
You do not have the required permissions to view the files attached to this post.
Diane Kauffmds
Posts: 2846
Joined: Sun Mar 09, 2014 8:13 pm

Re: Repairing a high humidity affected guitar

Post by Diane Kauffmds »

It's a beautiful guitar
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
Post Reply