Maple body cap

[Chris Richards]

Hi

Just wanted some thoughts on a fairly simple question...... I'm just about at the stage of gluing a book matched flamed maple cap(7mm thick) on a mahogany body and wondered what the consensus of opinion was to the method. Is it preferable to glue the two maple sides together first then glue to the body or do both the joints at the same time, the centre joint and glue it to the body?

Thanks
Chris

[Lincoln Goertzen]

I would recommend gluing the cap together, then gluing the two plates together. I have not done it the other way around, but when I have looked at the process, I have always thought that I had a better chance of getting things fit and aligned doing it my way.

[Nathan Dodd]

Get the seam on the face of the guitar right first and you will avoid any unsightly matching miscalculations on the most visible part when you are involving a lot more glue

[Warren May]

You can do it either way with good success. Gluing, first, gives you the opportunity to plane the seam in case things don't exactly match. Either way, using locating pins helps keep things from sliding around. Things can creep apart due to the glue and trying to glue in 2 directions can be a challenge depending on the glue's open time.

[Art Davila]

Thanx Chris for asking this question,
I have some burl that i have for one of my future projects and have not considered how to do this.
I was going to glue the joints tape the piece then apply to the guitar body all at the same time Like I have done with marquetry.
Now I think I will do the glue up and let it cure then attach to the body.

[John Catto]

Without a doubt you want to glue up the top before you glue it onto the body. In a perfect world you'd glue it up then run it through a thickness sander to get everything perfect but you can get away without that if you are careful with the top glueup. It's not overstating it to say that while success with this is largely a product of doing it right and having the right tools it's one of the trickier aspects of building and the very first thing people will pick at if they are looking to find fault.

To do it properly you need

A thick board about the size of the top wood but just a tad narrower (12" x 17" will usually do it). 8 C Clamps and at least 3 sash clamps.

Run the gluing edges through a joiner first and pay particular attention to them being square to the bottom. If you don't have access to a jointer clamp the wood (each side) to a brand new clean (no dents etc.) piece of MDF and use a router with a pattern following bit to "jish" each edge.

Put wax paper under the glue line and line up the two sides on the 12" x 17" base board. Clamp the 8 corners lightly, back them off a touch then apply the sash clamps and really crank them down hard enough to literally mash the fibres at the joint together, it cannot be too much. Tighten the 8 corners down hard after. Leave for around 6 hours or so.

There's an alternate method described in the Melvin Hiscock book involving clamping everything in place over a shallow center "lift". This is then removed and the clamps tightened down forcing the edges together. It works OK, I used it twice, once with very iffy results once with excellent ones. Nothing beats ponying up for the sash clamps though.

[Chris Richards]

Hi all

Thanks for all your thoughts..... And yes John I agree it's definitely one of the first things that people would find fault with.

I'm going to follow the consensus of opinion and glue the centre join first, at least then I only have to concentrate on one joint at a time, I have a jointer and sash clamps so should be on to a good start....

Thanks again
Chris

[Chris Richards]

Hi all

Well I got the centre join done with no real problem, more or less following John's method above and all went well, I'll get some pictures on here of the whole thing when construction gets a bit further down the line.

Thanks again
Chris

[Mark Wybierala]

I do a lot of similar things as mentioned but have found it really easy to superglue cleats at one inch intervals on each side of the joint and use a lot of rubberbands.

Super ditto about using locator pins. ...when you put the top on the body and I also put two into the joint. Things always want to slip when glue is wet and it also prevents long duration creep.