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PostPosted: Mon Dec 31, 2007 3:56 am 
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Brazilian Rosewood
Brazilian Rosewood
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Location: Bucharest, Romania
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Going to soon glue the FB, classical, fish glue.
The fit is perfect, passes the light test.

So does it really need a lot of pressure?

If not, why not just use a lot of very tight tensioned sticky tape same as for binding?

I was just looking at this LMI gadget...quite far from a 2 ton crushing clamp :)


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PostPosted: Mon Dec 31, 2007 4:51 am 
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Koa
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Hey Alex,
In my opinion, binding tape is not sufficient. I actually use those
fingerboard clamps from LMII and they generate quite a bit of clamping
force. There is enough surface area under the fretboard that you really
need to make sure you can apply enough pressure to squeeze out the
excess glue.

There has been a fair amount of discussion lately about fretboard
clamping. I use a dual-action trussrod from Allied and any backbow is
easily corrected after the fretboard has been clamped and the joint is
totally cured. So my clamping method is simply using about 5 of those
LMII clamps.



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PostPosted: Mon Dec 31, 2007 5:08 am 
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Brazilian Rosewood
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I wouldn't use tape, especially on such a broad surface. You need to be
sure you have clamped well enough to get all of the excess glue out from
all areas. My general rule is clamp until glue stops squeezing out, and
anything beyond that isn't going to too much good. I don't feel fish glue
is especially prone to starved glue joints like many epoxies and other
synthetic adhesives can be though, so I wouldn't worry too much about a
little bit of excessive clamping pressure. Just make sure it's clamped until
no more glue will squeeze out.

The LMI clamps are no good for gluing on a fingerboard in my opinion.
First, the clamping pressure is all at the edges of the board, nothing in
the center. More importantly however, is how are you going to ensure
you're gluing up the neck in the shape you want, controlling relief,
backbow, twist - they're just not designed with clamping against a
reference board in mind. I Just can't think of an advantage they have over
a bessey or cam clamp holding the neck against a gluing board, but can
think of a number of areas they hold potential to underperform.


With a water based glue this is especially important, as it's going to swell
near the fingerboard joint when the glue is curing, and usually want to
spring in to back bow as soon as you unclamp it from a board. This is a
main reason many have switched to epoxies for fingerboards. For those
that still use water based glues, double action rods have become popular,
or I still prefer clamping the the neck against a board to shape it in to
slight relief when gluing.

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PostPosted: Mon Dec 31, 2007 5:22 am 
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Brazilian Rosewood
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I guess I would not mind a bit of backbow, since I've put a bit of too much relief in the neck 




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PostPosted: Mon Dec 31, 2007 8:02 am 
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Koa
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David,
I've used quite a few different methods over the years. For a long while I
was using a clamping caul with the appropriate radius and slots for the
frets (since I fret before the fingerboard is attached to the neck). If you
start with a perfectly flat neck surface and a perfectly flat fingerboard
surface, I just don't see the need for a clamping caul. I generally get just
a wee bit of backbow but that is easily corrected with a dual-action truss
rod. Obviously, if you don't use one of those truss rods then I would
highly recommend an epoxy glue-up.

I have been using stainless frets for the past couple years and the
amount of leveling I have to do after using my current method is minimal
to none.

Those little tie clamps exert a surprising amount of force. And there is a
good distribution of the clamping force. Certainly nothing to cause one
to question their sufficiency. Is it any better to have the force dead in the
center as oppossed to the edges? - not really. In fact, I remember seeing
an aluminum fretboard caul of Frank Ford's that applied pressure right at
the edges. Regardless of center or at the edges, the job will get done
either way.

Obviously, this is just my opinion. But I do believe it is an effective and
sensible approach -- and one that has served me very well for the past
couple years.


Happy New Year's,
Simon




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PostPosted: Mon Dec 31, 2007 8:05 am 
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Brazilian Rosewood
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Tape would give nowhere near adequate clamping pressure.

I use as many spring clamps as I can get on it, one row down each side.

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PostPosted: Mon Dec 31, 2007 8:06 am 
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Koa
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Oh, I forgot to mention why I use these particular clamps over cam clamps
or C clamps. I like that they exert no twisting force. These clamp similar to
how vacuum does- straight down. Other clamps tend to push or pull the
workpieces. I use locating pins to nail down the location but clamping can
still move the pieces a little bit. I just find these twist clamps to simplify the
process and give me perfect results.

If you doubt their effectiveness, try one out on an offcut of the fretboard. I
think they are more than adequate.




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PostPosted: Mon Dec 31, 2007 9:01 am 
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Brazilian Rosewood
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I used to have about a dozen of those LMI clamps, but never really ended up using them. I've tried them many times, and I still simply don't trust them. I still would not feel comfortable "free clamping" anything like a neck/fretboard joint. Plus, I honestly find it much simpler and quicker to glue up a sort of bar clamp like a cam or Bessey. I'm sure those clamps work fine with the right glues and preparations, but I just don't like free clamping anything like that. Just a matter of personal preference I suppose.

I know many folks like to fret the board apart from the neck, but I've never been a fan of this method unless the builder has really done a lot of tests and refined a procedure enough to get consistent results. I see a lot of hand built instruments, and at first glance can almost always tell if the board was fretted before or after assembly. Some folks certainly can pull it off, but very few and far between in my experience.

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PostPosted: Tue Jan 01, 2008 6:22 am 
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Cocobolo
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i use a combination of spring clamps and releasable cable ties with titebond
this seems to work for me so far but i sure are better methods out there.

i have the policy of if it aint broke why fix it so i am happy with this method
for now and it a great method for beginers as you can experement with out
the for lots of expensive clamps.

joel.


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PostPosted: Tue Jan 01, 2008 6:37 am 
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Brazilian Rosewood
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Thanks everyone.

I ended up doing my own special clamps.  

1 inch width 1mm thick steely sheet to go  on the back of the neck, and oak thick flat stock on the fretboard, and 2 sturdy screws. 
When tightening the back sheet conforms to the contour of the neck, while the thick oak presses flat on the FB. 

Ive made 4 of these. Used a traditional small C for the soundhole, and a lot of strong sticky tape for the heel fret. 

Why don't I just use some factory made clamps? Only heavy metal types at the local HW stores, and they cost a whopping 35$ each.  I should be ordering a few Klemmsias  from Germany one of these days....


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PostPosted: Tue Jan 01, 2008 11:40 am 
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Brazilian Rosewood
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Unclamped..could not wait more than 12h 

There is no backbow...yet

I have heard spanish cedar is more stable with humidity changes..maybe that is the reason.




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