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I'm just curious who consistently joins their backs by sanding the edges flush, instead of using a shooting board and a sharp plane.

Thanks in advance.

Bill

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Eagles may soar, but weasels don't get sucked into jet engines.

I have a piece of marble countertop that I got from a kitchen installer that I attach some 240 grit sand paper to and then sand my tops and backs on that before I glue them. Of course I always do the "window test" to make sure the joint is tight before I glue it up and no light is visible through the joint.

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Reguards,

Ken H

ME

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I tried it on the last back I joined and I'm pretty happy with the results. I'll be trying it again

Me Too.
I use one of those precision 3' Blue ground levels from
the big orange box with 300 grit 1 inch wide ribbon sand paper and a shooting board.

Self stick sandpaper on my table saw top using a taller fence attached to the saw fence. Clamp both pieces together and sand away.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

My joins, all 2 of them, were sanded.  Self stick on a level.  I seem to have gotten good clean results.  Like Hesh, I planed first then finished with a few strokes of the sandpaper to clean up the tiny variations.

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Waddy

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[QUOTE=Hodges_Guitars] I have a piece of marble countertop that I got from a kitchen installer that I attach some 240 grit sand paper to and then sand my tops and backs on that before I glue them. Of course I always do the "window test" to make sure the joint is tight before I glue it up and no light is visible through the joint.[/QUOTE]

I thought I was the only one who used a marble countertop cast-off for jointing!!


I had a 1m x20cm x 4cm piece that was dead flat. I used it in conjunction with an expensive plumber's level with sandpaper until I dropped the marble and it snapped in half, head sinks in hands...

I'm gonna get another piece...it was so handy for all sorts of applications

I never finish any critical joint with sandpaper. We've been over this a number of times here so I won't reprise the reasoning, but a planed joint will always be stronger than a sanded one. If I sand a surface that is going to be glued I will always run a scraper over it to give a better gluing surface.

Does it matter? In reality probably not, but then as Mario always said (probably still does) it's all in the details.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Plane. Every time. Even if it's just to finish off the surface when it's been pre-prepped with sanding, or at least scraping.

Seriously, with the right tools, it's not difficult to joint 2" thick mahogany and the like, so rosewood is a snap. Spruce takes a bit more practice because you have to get the pressure right (most difficult jointing taks I've completed of late was the wedged archtop billet). Planing's more satisfying, easier to clean up, doesn't require me to wear a respirator, all good things in my book.

Mind, I do quite enjoy serious powered sanding (carving archtop/carved top plates with an angle grinder and a flap disk, anyone?) but until/unless I get a jointer, I'll stick to jointing with the jointer plane. Only joint I've sanded lately was the headstock veneer glue surface, since the Khaya was being very finicky about tearing out (main reason I prefer honduran for necks, really; so much easier to plane).

If for no other reason, I would use a hand plane to joint my plates because it is so easy.

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Rian Gitar og Mandolin

I started out sanding but have used a shooting board now for several years because it is quicker and I can put a \\ tilted joint which gives just a little more surface to the glue joint and makes a tighter and more invisible center seam.

I originally switched because of an article I read about many sandpapers using an soapy anti loading agent that could cause adhesion issues with some glues. But I have to say I have never had one that I sanded fail.

The piece of marble countertop I use is about 1 1/2" thick and about 6" wide. I attach self stick sandpaper to it also and then sand away. It only takes a few strokes to get the joint perfect. The marble is dead flat also and I use it for a lot of jobs when building the guitar like sanding the fretboard sides and back.

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Reguards,

Ken H

I use a really nice Australian hardwood Gordon plane. All my books say to use a plane and it is simple. A very fine cut and it only takes a few minutes to get a perfect joint. With this kind of work I recon it is OK to blame you tools sometimes. The first paltes I tried to do this way I used a cheap plane and couldn't workout what was going wrong. I was adjusting the pressure etc etc but it was getting gaps. Then I checked out the sole and it wasn't flat.

I was inculcated by my woodwork teachers never to run a plane or other bladed tool over a surface that has been sanded because the residue from the paper will wear you edge. I hear that in my head whenever I contemplate doing it and then don't.
Dom

[QUOTE=Dominic] I use a really nice Australian hardwood Gordon plane. All my books say to use a plane and it is simple. A very fine cut and it only takes a few minutes to get a perfect joint. With this kind of work I recon it is OK to blame you tools sometimes. The first paltes I tried to do this way I used a cheap plane and couldn't workout what was going wrong. I was adjusting the pressure etc etc but it was getting gaps. Then I checked out the sole and it wasn't flat.

I was inculcated by my woodwork teachers never to run a plane or other bladed tool over a surface that has been sanded because the residue from the paper will wear you edge. I hear that in my head whenever I contemplate doing it and then don't.
Dom[/QUOTE]

I guess this could be true if the paper had a anti loading agent but that would be left behind on the top surface not the edge other than just a micro amount. And considering that all timber gets sanded one way or another; if applied in the absolute, this thought process would leave use with no use for a planes

just a over the top observation

i have always used a plane. why? because that is how i learned to do it. i never tried sanding because using a plane either on a shooting board or in a vice is very quick, easy and reliable. no reason to change. i never tried the power jointer for the same reason, and the plane is quiet as well.

but i've also read some of the research results going back to the pre ww2 era and subsequently, which have all indicated that a joint surface which has been shear cut, i.e., planed or scraped, has better glue adhesion and produces a stronger joint than one which has been abraded. so by circumstance and habit i stuck with what is the "better" way.

does it make a difference? i can't say. certainly a lot of guitars have been built with sanded joints. i've not heard any reports of their having higher failure rates than planed joints.

but if the one method has been objectively determined to be superior, and is no more difficult, or expensive than the inferior method, i think i will stick with superior one.

I read in a post on this web-site that if you plane from one end of the two pieces to the other, you will end up with gaps at the ends.   That was my result too.  How do you overcome that?  The post, which is in the techniques section, says plane in the middle first, but ISTM that if you plane in the middle, then plane from end to end, it takes out the middle dip and would still produce the same result that you would have had if you had planed from  end to end to start with.  What is the best technique for planing the seam?

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Waddy

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Thanks folks...I really appreciate all the input. I've been truing an old Stanley No. 6 plane lately, on one of the Woodcraft marble slabs (supposedly accurate flat to .0001) and my plane now appears flat, and the blade sharp. But, last night I grabbed a low-end top, and proceeded to do some practicing. Despite my best efforts, I still seeing tiny gaps on my test pieces.

More than likely this is just a try, try, try, then WHAMMO, you figure it out. I think I'm not getting even pressure from the plane, a common newbie mistake.

Thanks again for all the advice. I've got to get this process down and join a few tops/back!

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Eagles may soar, but weasels don't get sucked into jet engines.

what you describe should not happen if proper technique is used.

as with most plane cuts, you have to control where your pressure is applied. at the start of the cut, the pressure has to be on the toe, shifting to an even pressure as the whole sole is engaged, then shifting to the heel as the toe and the foresole goes off the stock till the cut is complete.

practice on some thin stock sawn from 2x4 or 2x6 construction grade lumber. it doesn't take long to acquire the knack.

Thanks for the tips Michael, I'll give that technique a try!

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Eagles may soar, but weasels don't get sucked into jet engines.

I must be strange--I use my joiner--I run both pieces through and have never had to touch them after. I've had perfect joint on a dozen tops so far. Why doesn't anyone use their joiner????

[QUOTE=WaddyT] I read in a post on this web-site that if you plane from one end of the two pieces to the other, you will end up with gaps at the ends.   That was my result too.  How do you overcome that?  The post, which is in the techniques section, says plane in the middle first, but ISTM that if you plane in the middle, then plane from end to end, it takes out the middle dip and would still produce the same result that you would have had if you had planed from  end to end to start with.  What is the best technique for planing the seam?
[/QUOTE]

The plates are book matched and clamped down on the shooting board. The passes are single push complete passes. I use and feel it is best to use a #6 or #7 jointing plane to assure a level pass. But I have heard of those that use a jack plane with success. so in essence you are only planing a double stacked single plate. So both plates will be exact mirror images of each other.

waddy, i just had a look in the techniques section and couldn't find the post describing the planing technique you described.

could you give a better pointer?

Yeah, I was looking too, and I couldn't find it either.  It was a tutorial post by Serge, and I may have seen it in the archives.  I'll look and see if I can find it.  It was last week when I was browsing for information.

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Waddy

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