Jumbo Acoustic Re-Build

[ozziebluesman]

Hi everyone!

This jumbo acoustic was given to me by a friend who has a large guitar collection. This one met with an accident and has had a fall. It also appears that it has been very wet or maybe through a flood at some stage. The top was cracked in a number of places and it has a split either side of the top under the fingerboard extension. It is a dovetail neck join and although the truss rod shows some rust it is operating correctly. The back is three piece and the sides are genuine mahogany. No cracks but a few dings to fill. It has also been through a room during painting with white paint and the guitar has wore some paint spots. It was hand built originally by a prominent Queensland guitar builder as a gift to a friend and I reckon it is about thirty years old. The workmanship is good and I believe it was a prototype. It is a big mother and the previous owner, not the owner it was built for said it was a good sounding guitar. The neck is mahogany, straight as and the fingerboard and frets show little ware. The frets are jumbo stainless steel and it has some good Grover tuners. I have never attempted removing and fitting a new top so it is going to be great experience for me. The guitar has been built using hide glue so it should not create too many problems removing the top.

Here are a few pictures






Started the rebuild by removing the plastic binding. Took some time but was easy enough and no damage. Next the top was removed and it took me about an hour, again no problems as the hide glue made the job straight forward. The next job took an hour also to remove the piece of top between the fingerboard and the top of the fingerboard extension. That was tricky! I then decided to remove the bridge as it looks in good nick and matches the fingerboard. Some so and so used epoxy for this job. That took some work also but I won out in the end. I am very pleased with the way the project is coming along as this is my first go at a major re-build. Some more pics for you.









I have selected some Lutz Spruce from Shanes great deal sometime back so the top cost $15. It is beautiful and rings like a gong. There are a few imperfections but I was able to dodge most of them.

I have one question is it possible to fit the top without removing the neck? I think it is possible but wondered what you all think?

Thanks for looking to be continued......

Cheers

Alan

[jeffhigh]

It is possible to do without removing the neck, but I reckon you will be regretting it.
I'd be pulling the neck and making sure the neckblock is secure.

[nnickusa]

I have no idea, but I'm watching with interest...

[liam_fnq]

I've got the same species of dust bunny hiding in my guitars.

[ozziebluesman]

More pictures of progress on the rebuild:



Brace sizes are as per the specs of the old top and are some nice Englemann Spruce from Graham:
Transverse brace 10mm x 15mm.
Xbrace are 8mm x 16mm.
Tone braces 7mm x 13mm.
Finger braces 5mm x 13mm
I will be using a sound hole patch in the brace design also to help stop the splitting that happened to the old top.

To be continued.....

Cheers

Alan

[Kamusur]

Great work Alan, it looks like it was well made in the day which definitely helps in your revamp. I probably would have found it hard not to use the old braces if i was tossing the top.

Steve

[ozziebluesman]

Thanks for your comments Steve.

It is a well made guitar so that's why I decided to rebuild it. I think getting wet was not good for it and I reckon it happened a while back. It has some pencil into under the top but no date anywhere. The spruce top was split in many places and I managed to damage the ends of the X brace when I was removing the top so I thought lets go with new braces. I like to use sound hole spruce patches in all my builds now. I reckon it may have saved the splitting at the neck if the original had the patch.

Cheers

Al

[Kamusur]

Just my thriftiness shining through Alan and also eyed the Paua/Blue rosette (hate to waste lol). thanks Al

Steve

[ozziebluesman]

Thanks Steve you have just given me an idea and that is dangerous a times. I will see if I can lift whats left of the shell rosette and use the shell in the endgraft to make up the shortage of shell in the rosette! Hmmmm

Cheers

Al

[ozziebluesman]

Could not save the old pearl rosette so have made a new one from some lightly figured blackwood. I have some lightly figured Blackwood binding and an engraft that will go nicely with the mahogany. Today the sound hole patch was glued in and the rosette made and glued in with black white black purfling. Nothing fancy as I am trying to make the guitar look natural when all finished. I may even age the top to a darker shade.
Some more pics for you





to be continued...
Cheers
Al

[ozziebluesman]

More pics:




to be continued
Cheers

[ozziebluesman]

Early start this morn. The top braces are all glued in using Titebond.
A pic for you:

cheers
Alan

[ozziebluesman]

Voicing this top is pretty easy as I will be copying the old tops bracing design and then maybe fine tune it later.

To have a bench mark I weigh the top in a braced state it come in at 310 grams.

I have also scalloped the ends of the transverse and the x brace to 2mm thick at the ends. I measured the depth of the notches that are already cut in the rim so the the top will fit nice and snug. You will also see I have left the finger and tone braces where they butt up to the x brace at 4 mm thick.

This top design tucks the lower bout x brace ends so I will do the same.
I check the tap tone and the top has dropped in pitch from rough braced D to C#.

Now to shape the two tone, finger braces and after that task I have dropped the pitch to C. A little more material material taken from the x brace and we are now at B, the same as the old top. I have had no experience with these big wide mother tops (425 mm 16 3/4" lower bout) so I am happy to copy the old top and go with B. The owner of the guitar said it used to be a good sounding guitar in it;s day so I hope we can regain that!

I am happy with the tap tone so now it is time to address the butt joints of the finger and tones braces where they intersect the x brace looking to give the top a little more flexibility.

I glued a cap on the x brace and sanded the braces down with 220 grit sandpaper and then 400 grit.


Before sanding the braces I weighed the top again and it id now 299 gram.

I used the spool clamps and did a dry run first to make sure the top fitted and after a few little filing and shaping it fits not to shabby.

The top has been glued at the neck end around to where the x brace and transverse brace tuck into the linings. I used a plastic syringe filled with Titebond and squirted in plenty of glue.

I predicted a lot of glue squeeze out so I lined the inside of the body with some newspaper. Should keep things nice and clean inside the box.

One thing I did forget to do was sign the inside of the top. I maybe able to do that later if not I will make a small patch explaining I did not build the guitar originally but just restored it.



That's it for today, good progress.

Cheers

Alan

[DarwinStrings]

Nice bit of craftsmanship Alan especially dealing with it with the neck still on.

Jim

[ozziebluesman]

Thanks Jim I am stoked I pulled it off! The neck set was perfect so it was just the matter of getting the new top to fit in the old brace notches, I took off the clamps this morn, pulled out the paper inside the body and gave here a tap and as usual the pitch has dropped two tones to G. The neck is straight and lines up and there is a little over hang in spots that will be removed when the binding channel is cut.

I do have a question for you all and that is why would the original builder have tucked the x brace at the lower bout end? The tap tone is big as you would expect a 16 3/4 inch lower bout guitar to sound but it has a short attack! It seems like the top will not sustain like I expected and I put it down to the feet of the x brace being tucked. Love to hear some discussion.

Cheers

Alan

[Nick]

Been enjoying watching this resto Alan, you've done a brilliant job so far and it's probably going to end up better than it was pre 'accident'.

[ozziebluesman]

Hi to you all and Happy New Year.
I started this guitar re-top sometime ago and my health went down hill so all stopped in the workshop. Health is much better now so back in the shop catching up on all my projects I had started. This Jumbo was going to be thrown out but I decided to have a go at a re-top and it worked a treat, I used one of the $10 Lutz tops that Shane offered on special. It's a big boomer, with great sustain and finger picks nicely as well. Very pleased at the outcome. A few final stage pics for you all:
Cheers
Al

[Bob Connor]

Nice when a plan comes together Al.

Looks great.

Regards

[56nortondomy]

A great save there Alan.
Wayne

[colburge]

Very nice

Col

[demonx]

Great work!

[simso]

Impressive you managed to do it without removing the neck or fretboard.

Steve

[woodrat]

Nice one Alan......Well Done!

[charangohabsburg]

Two times (the guitar + you) successfully restored to good health!

Cheers!

[HighMountainTW]

Great job! I actually have a couple guitars that I want to do the same to. One of them with the 'neck still on' issue. This inspired me. I'm starting tonight!

Cheers