Top Thickness Question

[RobStark]

Ok, so I have searched and searched through new and MANY old threads here related to questions on the thickness of a les paul maple top.

I understand that the standard on 59's seem to be between 9/16" and 5/8" at the thickest part (although some say there are examples of 1/2").

I also understand that the thickness is directly related to the neck plane angle. A 5/8" top thickness should co-exist with around a 4.4 degree neck angle and a 1/2" top thickness should go together with a 4.2 degree neck angle (increasing thickness = increasing angle and visa versa).

Ok so that's all fine and dandy. But my question is much simpler and noobish. Let's say I want a 5/8" top and let's say I have a bookmatched maple top already resawn and the pieces are 5/8" thick. After I glue them together and glue them to the body and start carving the top this means I basically leave the middle portion alone, correct? I would carve around the edges and the rest of the body but leave the middle portion alone (where the bridge and pickups sit) since it is already at the target 5/8", right? Is this normal? Do people generally start with tops that are already planed to their target thickness? Or do they generally leave a little room (say start with a 3/4" maple top when their target will be 5/8" in the end) before they start carving? And if they do this, how do they gauge/measure when the top is reduced to the appropriate thickness once they start carving? It is already glued onto the mahogany body back so is it just a matter of subtracting the mahogany thickness from the overall thickness of the body to determine if you're at the target top thickness? What tool would you use since the target thickness of the top is all the way by the bridge/saddle area?

Im asking because I've seen videos and build threads of people carving that middle portion down also when they do the rest of the body carve, but I've also seen people not touch that middle portion. In my simple mind, it would seem easier to just have the top already at the target thickness (5/8" for me) and not touch that part.

Also, does the pickup plane affect the overall height of the top? No right? The highest point of the top is behind the pickup plane, correct? Or am i wrong and does the pickup plane start at the bridge? I seem to see a lot of conflicting info on the internet.

Thank you SOOOOOOOO much for any help.

 

[ARandall]

If people have carved the middle portion, then its likely the top was too thick, or they wanted a different look/aproach/feel etc.

The top of the vintage LP is 5/8", and if you look at the ExNihilo vintage burst build thread along with the Bartlett build there are a whole heap of details about how the carve works and looks.

The pickup plane starts at the bridge or just a little behind it. As both the bridge and t/p are at full thickness after the initial carve it matters not precisely where you start it. The main point of it is to allow for the neck pickup ring. The Ex-nihilo thread gives very detailed explanations here - there is quite literally every bit of info you could ever need in that thread (as well as carve templates).

The Bartlett plans are also a key too. They show graphically what is going on, as well as giving all the details that you seem to be asking about.

 

[Barnaby]

Well, part of it is the condition of the wood. You need a perfect gluing surface on the underside and a smooth finish on the top. If you get it planed to exact thickness, you have absolutely no wiggle room for these things. Most wood comes from the supplier with less than ideal surfaces and it's also trickier than you may think to align the halves perfectly when gluing. 3/4 is safer.

There are other reasons, I am sure, but these are the main ones that occur to me immediately. I'd rather plane away a little extra than bemoan an imperfect top. Personally, I carve the tops before gluing them to the body, but know that most don't. The reason I do it is because I chamber my instruments and like to undercarve and tune the tops.

 

[Bill Hicklin]

^This.

In most woodworking it's easier (and less risky) to start with a little excess material and cut it away. This is why, for example, I always leave a bit of extra (~1/16") at the side of the neck joint on cutaway guitars, and carve it down together with the heel after assembly. Remember, removing wood is a helluvalot easier than adding it!

 

[emoney]

Ditto to what's been mentioned in that it all depends on in what stage the wood blank is in
when you receive it. If it needs planed in order to achieve flatness, then you need to start
at 3/4". If it's machined when it comes to you, then it depends on how steep you want your
carve to be. "Vintage Correct" is 5/8" but you can get a shallow carve that looks nice out of
a board that's 1/2" thick as well.

 

[pshupe]

I'm with Barnaby. I usually purchase 8/4 (2") maple for the top and resaw. Then might plane it down to no less than 3/4", just enough to get it flat really. Then glue together and thickness plane to 5/8". Keep in mind that with figured wood there is a higher probability of tear out. That isn't that important with a carved top as most of the wood will be carved away after thicknessing. It becomes very important for a junior style with a maple cap. Ask me how I know! You have to be careful with mahogany as well. If there is an option you should thickness sand to final dimensions instead of planing or jointing.

Cheers Peter.

 

[RobStark]

Thank you all for the replies