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OK.... I have my two top pieces of Quilted Sapele Mahogany to join. I have the seam almost to where I want it. There is about a three inch length of seam that I'm not happy with. It's almost there, but not perfect. It is for an electric top. Some of the bad seam area is in where the neck pocket will go as well as the rhythm pickup. Should I ignore it? Am I being too picky? Will the glue fill this in and hide it? I put the pieces together and sanded them both together at the same time. I just can't seem to get it perfect. Any ideas?
Thanks!
Mark

Hmm maybe tape some 80 grit to a flat surface and sand the sets together on that? It's better to get it perfect. Or borrow 30 seconds of shop time with someone who has a jointer.

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Mark -
Ive never built an electric, but for an acoustic, there is no "Good enough" Its either a perfect join, where no light shows through the seam, or its bound to fail.

If your mahogany is going to be laminated to a solid body, and your seam, not in plain view, or not visible at all, I see no harm, however, as Ive never built an electric, in not aware of any pitfalls?


LanceK

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Lance@LuthiersForum.com

I don't think there would be any "pitfalls" of a poorly joined then laminated top.. Guess it's all personal.. I'm a bit of a perfectionist and little stuff drives me crazy. Most people probably wouldn't even notice it but YOU will always know it's there.

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Jason, the seam won't "fail" on a laminated top...(as in the conventional sense of opening up)...but, try sandpaper 3M'd to a side of your level (you do have a level don't you? I wouldn't ever try building a guitar without a level )...bookmatch your pieces with the centerseam edges to your left...butt the other edges to your tablesaw fence (you do have a tablesaw don't you? )...hold the stack down on the saw table and move the level's edge in long smooth strokes along the centerseam edges, checking the seam's fit often...any discrepancy between the two edges will cancel each other out and you'll have a perfect join in 3 or 4 minutes...by the by, I use 120 grit since I run the pieces thru my saw or a sharp block plane first to get close...hope this helps!

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[QUOTE=L. Presnall] Jason, the seam won't "fail" on a laminated top...(as in the conventional sense of opening up)...but, try sandpaper 3M'd to a side of your level[/QUOTE]

I agree it won't fail but Mark sounded as if the edge was off enough that it was visible. I couldn't handle seeing a gap right down the middle of an otherwise great top.

I don't need a level, we've got a new spiral head jointer thats nothing short of amazing.

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Jason, I'm sorry, I meant to offer that post to Mark...wow, how do you like the spiral cutters? I saw the ones in Grizzly's catalog and then on the Taylor site they have a neck cutter setup using sprials that's SWEET!

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I think the spirals are amazing. We have the Grizzly 12". You can run a 10" billet through them. One day maybe we'll get the 20 or 24" so I can flatten all these one pieces I've been stockpiling

With really intense curl our planer will have a lot of tear out, with the spiral jointer it comes out looking like it's been sanded already.

They are also handy when you get a chip, the 4 sided blades can be adjusted individually.

You can just buy the spiral blade assembly for shapers from Grizzly. I'm wonder if you could stack them or custom order one for any jointer/planer.

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Jason, yes I have their 3hp shaper, and I think that if I order the 4" spindle I can use the spiral cutter...I may have to give it a try...my 2" tall straight cutter is about ready to retire...

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This is just so much easier to do with a well tuned hand plane and a shooting board, and the joint will be far superior to a joint with sanded or power planed edges. Sanding leaves a torn surface and the marks from the power planer will leave little ripples, however small, and that means a weaker joint. Like the others say, I don't think it will matter much here, but it's just one of those things that are so easy and fast to do with a hand plane (I use a Bailey #5 1/2 for my acoustic tops and backs, but anything from a #4 and up will work well) that it's well worth the effort.Arnt38607.232337963

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Agreed, good plane, shooting board, a few minutes, and it should take care of itself. If it's not a 5/8" electric tops set, that is. Those are a bit more...annoying.

For a laminated top on an electric, it really depends on where the 'gap' is. I've done electric tops that were perfectly joined along the entire length of joint that ended up exposed, but that were kinda funky in bits outside the body outline, and the bit where the neck pocket/neck humbucker went. Because, well, that part of the joint gets routed away anyway on my design.

There's no structural downside to having a slight gap, but if it's in an area that isn't getting cut away, spend the time and get it right.

All,
Thanks for the responses back! I agree with Lance on the "perfect" seam. I do want to get a system down that works for when I do start making some acoustic guitars, so I want to get a procedure down for when that time comes. There is no issue with failure. It's just me wanting the join perfect. The join is good for about three quarters of the way towards the neck pocket. Then it opens up a very small amount. The neck join takes up some of it and the pickup will there as well. I don't want to keep sanding and adjusting. I think this will throw off the center line. I put the pieces together and sanded them lightly figuring they would match.
What is a shooter board? Square edge next to the top pieces to use as a guide?
Thanks again all.
Mark

There are a few illustrations in the MIMF library, maybe on the jigs pages here. A 'shooting board' is simply made: flat board longer than the pieces you're jointing, two bits of scrap (flat, straight edges) a little longer than your board, anywhere from 1/4"-1/2" (or bigger..but it just gets silly). That, and a well-tuned handplane, set to take a minimal amount of wood off. Tiny is best, and a #4 will do, #5 will do nicer :-)

Right. Your big flat board is the table. Place one of the smaller scraps on it, close-ish to the edge (your plane needs to be able to slide along on the table, on its side). Close your bookmatched set up, so the edges that need jointing line up properly and cleanly. Place this on the first bit of scrap, the edge to be joined only just overhanging the scrap piece. Place a second bit of scrap on top, and clamp this whole 'sandwich' down. You've got this, basically:

+++
-----
-----        <- halves of bookmatched wood to be jointed
+++         &nb sp;<- scraps
============ <- table

Basically, you've firmly affixed your bookmatched set, lined up, and ready for levelling. Now take a plane, tip it on its side, and plane using even, straight strokes. It'll hit some bits, miss others, but that's normal. When it's straight, it'll take off a fine curl the entire length of the piece. Alternatly, a sanding block will do, but isn't much fun.

What this does is take the same amount of wood off of each half, maintaining the perfect bookmatch in terms of figure. Check with a straightedge for rough controls, and 'candle' (hold together, up against a window/natural light, and see if you can find any gaps) for final fit.

Here's my shooting board set up, pretty simple. I used a scrap piece of hardboard to set the top plates up off the table a bit. I use a #4-1/2 smoother and it works out pretty good.

It'd probably be slightly quicker if I had a longer joiner plane. As it is now, my only problem is I can't find the glue joint after they're joined. I keep forgetting to notch each end of one of the plates so I can center it up later.

Using a level with sandpaper on the edge works okay, but it's much more fun to make shavings than dust.

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Jonathan Kendall, Siloam Springs AR

Mattia - Got it! Very descriptive and understandable. As always good advice!
John,
Thanks for the pics. I was doing something like this but on my vise.I have the plates sandwiched between two boards between my vise jaws. I leveled the top pieces and tried to lightly plane them. Seemed to work until I put them together. I think I need a new plane. Mine is too small. This could be my problem. The plane did not work too well. So I tried sandpaper on a block. I'm getting there, but it's just not tight enough for me.
Can't thank you guys enough for the info!
Mark

It took me a little trial and error to get the right feel for getting a good straight edge with the plane. I do a lot of stopping and holding up a machined straightedge to it to gauge my progress (or regress, as the case may be).

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Jonathan Kendall, Siloam Springs AR

Just remember that you are planing figured wood, and take light cuts! If the throat of your plane is adjustable, close it right down to a sliver...if you run into problems, plane from the other direction...if you still tear out, go with the level and sandpaper route...it does leave a "rougher" edge than a plane, but we're talking a microscopic level and the glue doesn't mind...a torn out edge from a plane can be more than glue can handle! Good luck tho, I'm sure you'll do fine...you've figured out how to get this much of the job done after all!

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The glue _does_ 'mind': they found back in WW II that wood prop layups that had the layers sanded to thickness tended to fail, while the planed ones didn't.

The mantra for hand planing is 'sharp'. I'm also assuming your plane is properly tuned up.

A freshly worked surface will glue better than one that has sat around for even as little as 15 minutes. It has to do with the 'surface energy' of the wood: how many open molecular bonds there are. When you remove wod you break chemical bonds, and it takes a little while for them to glom onto something. If you present them with glue they'll grab that. Have all of your gluing stuff ready to go as you plane.

Alan, point taken, but then sanded edges are glued every day and hold up fine...especially since the top in question will be laminated to a solid substrate...I agree with you that a planed edge is better, I was just trying to get Mark to an acceptable spot with a way that gave him the best chance of success, all things considered!

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Alan,
Point taken for sure. But this is for a laminate top on an electric and I think it's not as important as for an acoustic for obvious reasons.And yes I want a nice invisible seam as well. I need to get a better plane I think.Thankyou for the knowledge!
Larry,
I think I will go out and get a better plane and try it that way.If I can't get it I might just use the sandpaper method for right now.I agree with both of you on a good sharp plane. I'll just go slow and try to use as fine as I can get away with. I DO NOT want to ruin such beautiful wood from Bob C! Man I hope to show all of you a guitar one of these days!
Mark

Mark, we're all looking forward to seeing it! Good luck with the seam, and above all, GO SLOW! I sharpen and polish my plane blade immediately before I make an important joint like this...like I said, I'm sure you'll do fine!

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Thanks again Larry! And for the vote of confidence! I'll get it yet!
mark