Official Luthiers Forum!

Hey guys. I just started to French Polish my top !!! But before I did so , I sanded of all tiny marks and misscolorations, fingermarks etc. looks GREAT !! accept for some small things. allthough its my first, so I am satisfied with the result so far.

Now, Before I started to finish sand the top, it was about around 0.098 and now as I´ve been finish sanding, I am not sure what it might be, the tap tone is great. But it might be real thin !!! So I am really worried about how it will hold up with strings on . cant even imagine my reaction if it breaks. might just do a nice dive from the eifeltower then or something. . it´s a real stiff top. but how thin can a top be with normal bracing patterns. ???? " before it breaks"

Lars.

Chances are you'll be OK with a "stiff top and normal bracing"!

_________________
JJ
Napa, CA
http://www.DonohueGuitars.com

You will likely be just fine. One of my L-OO was 0.083 prior to final sanding
It is one if the best guitars I have ever made!!!

_________________
Andy Z.
http://www.lazydogguitars.com

But, this is an SJ. !! . and I would bet mine to is around that thickness. So would you think I am ok even thought its an SJ ? 15.5 lower bout.

Lars...at this point, just string it up and see what happens. You might be pleasantly surprised!

_________________
JJ
Napa, CA
http://www.DonohueGuitars.com

Lars, go better get some sun before you string that baby up!

I'm guessing light strings would be best, anyone know the # difference between light and mediums?

_________________
Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

Lars,
You will probably be okay for awhile, but when you set you neck angle, you might want to make a straight edge fall a little lower than the top of the bridge with frets in. Your top will probably pull up a little more than normal. I remember in Kent Everett's voicing class, he mentioned that he would never build a top less than .10". But I know other builders who have done it successfully. Good luck, and keep us posted.

_________________
Tracy
http://www.luthiersuppliers.com

I built one of my early guitars real thin, it was before I measured stuff, so I'm not sure how thin it is. I say "is" because it is still playing after 30 years, though the top is wrinkled.

Don't make the bridge thick, and let the straight edge touch the top of the bridge at neck-set time.

_________________
https://www.facebook.com/profile.php?id=100008907949110

What kind of guitar are you building? If it's OM or other small body guitar you're fine but if it's dreads then it's iffy. I had a top that went to .09-.085" and I had to scrap it... I was building a Dread.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

The first thing I'd do is measure it with one of those long reach deep throat thickness gauges through the soundhole. No sense in just guessing how thick it might be, IMHO.

_________________
Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Lars bro I think that you are fine. The top may be a little thin for an SJ and the particular top that you have but OTH you are likely to have a very responsive guitar.

As mentioned keep an eye out for top distortion over time and use only light gage strings.

I'll bet you are pretty excited about stringing her up? On my first I was absolutely sure that the neck was going to come off when I strung it up. It never never did unfortunately.... but you should have seen my face when I was first stringing her up. I kept myself as far back from the guitar as possible as the loud creeks and groans were sounding off as I tensioned the strings. Looking back this was pretty funny probably to anyone else but terrifying to me.

It all worked out though and so too will yours bro.

I have one of those wonderful little toys called Hacklinger caliper, and one surprising things was that it is quite hard to thin the top on a completed guitar using finer sandpaper (360-400 grit or so, even 200's) What I'm trying to say is that a reasonable "final sanding" is not going to alter the thickness by a noticeable amount, unless you get drunk and dig in it using 80 grit on a hardwood pad....

_________________
Build log

I guess I need to get me one of those deep trought calipers or similar then and then simply keep my head away as I string her up hahaha. Thanks you all for making me feel better !!!!

Sincerely Lars.

Lars,
I gave you the wrong information for setting the neck angle. You should have the straight edge slightly higher than the top of the bridge with your straight edge sitting on top of the frets. Sorry about the confusion. Good luck!

_________________
Tracy
http://www.luthiersuppliers.com

The opposite re setting the neck.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

You can't get those through the soundhole and around the braces. But I agree that you didn't remove much with fine sanding--unless you went back to coarser grits.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

If you can roll it up into a complete circle.... it might be too thin.
If its tap tone is somewhere between "Cheap Poster board" and "Construction paper".... it might be too thin.

Then again... if you make the braces a little wider, then shape them with a gouge so that it has a shape kinda like a trumpet or a triangle shape -- thinner at the top and flaring wider at the bottom... they shouldn't telegraph too bad.

Do what I did with one that was *way* too floppy... retop a $30.00 Thrift Store beater....
Turns out that mine sounds pretty good with that Thin Floppy top....

Thanks

John

Even if it is too thin and you see the bridge rolling forward, you can at least salvage it by using one of those JBL Bridge Doctors. I've salvaged a fair number of Yamaki cedar topped 12 strings with those. Not ideal but a very practical 'after the fact' fix.

There is definitely some excitement when you're tensioning it up the first time. As I was hearing the creaks and snaps and my heart was pounding, I kept thinking of that line in Charlie and the Chocolate Factory: "The suspense is killing me...I hope it never ends."

Darrin

Good point, Howard! I don't know what I was thinking. Obviously, I'm not in the habit of measuring the plate thickness on my assembled instruments, though I do use my long reach thickness gauge all the time to measure plates before they're glued on the rims.

One could make a thickness gauge that could reach in the soundhole.

_________________
Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/