On 12/24/2015 9:53 AM, OFWW wrote:
...[preceding discussion elided for brevity]...
Ya' lost me there...no idea how is intended to relate to current discussion.
US FPL (Forest Products Lab) has performed extensive tests on the
question and concluded "no"; in fact, the test data shows that the
higher the clamping pressure, the stronger the joint up to the point of
physically crushing the material. I've posted links to this in the
(fairly distant) past and unfortunately don't seem to have a bookmark at
hand so will leave it at that for now, other than to point out the
specific testing (as is virtually all work by the lab) was done in
support of the production manufacturer of wood products, and doesn't
really reflect a home-shop rec woodworker environment. Consequently,
the pressures achieved at the upper limit there exceed what generally
would be found in work rec.wooodworking participants shops. Which
simply supports the bottom line answer of "No" is why I included the
discussion. (Leon may be the one exception here with his known
penchant... :) )
The key limitation in a quality glue joint as far as material prep
causing poor adhesion (other than that of ill-fitting joints) is have a
fresh, unburnished surface. If one were to, for example, joint the
material with a set of dull knives it's possible for them to "hammer"
the edge rather than cleanly slice the fibers. In this case the
micro-pores that are critical for the bonding to occur can be closed and
thus the glue simply lays upon the surface instead of actually forming
the bond. I forget, it may be that Hoadley in his tome on wood
discusses; I'm virtually sure it's in the FPL Handbook (all again I've
not looked recently to confirm).
Sorry, I was watching some lamination jobs and some Japanese big beams
and how they were jointed. Just thought some of it was common to
Hmmm, the same pores for bonding that are also important for finishes
and stains to adhere to. I think I understand that, so an overly
"finished" joint can be a disadvantage and coarse sand paper the best
Sanding isn't terribly effective but it's not particularly harmful,
either. The ideal surface for a glue joint is one fresh off the plane
or a chisel, say, after final tuning or a tenon for it's mating mortise.
The sharper the tool, the better.
The problem outlined above is one that happens almost always with
machine operations where the knives aren't kept sharp--this mostly
happens because with a motor doing the work it's easier to keep putting
of the sharpening past when "should have done" and since the knives are
cutting in a rotating arc, when the dull surface contacts the material
instead of cutting cleanly as when sharp it effectively hammers the
surface. It's pretty common to see such burnished surfaces on
commercial framing lumber from the planing operations as an illustration
or in the mouldings in the box stores where the shaper cutters aren't
changed out frequently enough...as you say, it'll really show up in the
latter when finishing as differences in absoprtion and reflectance even
if lightly sanded--it can take a lot of effort to remove the traces
entirely. One's best off to select sticks that aren't so instead...
With hand tools, otoh, you need enough extra effort to make them work
that one will stop and sharpen before reaching the point...or just quit! :)
I love sharpening my stuff and checking it out, like chisels against
the end grain, and planes, planer and jointer. Just to see the ease of
hand tools usage with the right edge is a thing of beauty to me. Even
with router bits and saws. I love both power tools and hand tools and
seeing the old planes and special purpose planes are a thing of beauty
to me. Even the bench seats used for WW. I wish I could have done this
from the beginning.
Got side tracked again. But thank you for your valuable insight and
sharing your experience.
In the early days of the web that was a great resource, now, with the
psuedo wisdom of twenty something web designers, and left half bell
curve government employees, that information from UPL is getting more
difficult to locate lately.
Soon as the ComCasts, Verizons, AT&T's, et al got into providing
Internet access and locked it down, and regulatory capture once again
rules another public venue, the web has turned into a money grab,
nothing more than a pallet for blithering millennial idiots to somehow
"monetize" another one of their stupid ideas.
Screen real estate on your computer, once belonging to you, is now
theirs, and by damned they're going to use it, and screw you. Even worse
if you have a mobile device/tablet.
The asinine stuff is mostly free though, and the hive mind loves it ...
even though their data and privacy IS the product.
"Get off my lawn you blasted kids ... LOL
Google's core competency is making money off of advertising.
It is true that their search engine has become progressively
less useful over the years - part of that is their fault
(the recent idea that it should search for what it thinks
you're looking for, rather than on the words you enter),
but most of it is due to people gaming the system to try
and get their site to show up first (there's a whole
"Search Engine Optimization" industry that sets up bogus
websites linked to each other, to try and make one look
busy and important to Google).
On Sun, 27 Dec 2015 14:35:31 -0000 (UTC), John McCoy
Sure, and that's the problem. Though I was specifically referring
their search engine.
Their ranking has always been an issue (pay me for better ranking) but
the fact that they're now the arbiter of truth makes matters worse. As
I said, I've never trusted their search engine and it's only gotten
I don't beleive you can pay Google for ranking (altho
you can pay to put an ad at the top of the results,
labeled as an ad).
But for facts (i.e. truth), now-a-days I go to Wikipedia.
You have to be a little careful with what's there, but
by and large it is very accurate.
While I agree that Wikipedia is a great source for information, no one
should ever take what you may find there as "gospel"
The reason for this is that Wikipedia is a collaborative effort by the
internet community (i.e. the very people who go to Wiki to seek knowledge).
Most posted there IS accurate but you don't want to be citing it as a
source. Instead, use it as a "lead" to show you where (from the
annotations there, if provided) to find the documented information you
seek backed by authoritative sources.
Just as an example, if there was a Wiki entry for John McCoy explaining
how you developed a strain of hybrid corn that was resistant to every
known form of fungus that typically attacks the corn plant. I could
come along and add additional information to your Wikipedia entry
stating that in addition, you were related to McCoy family of the
Hatfields and McCoys and that your great great grandfather was hanged
for stealing horses shortly after the Civil War and that your
grandmother missed the hanging since she was busy tending the family's
bordello in St. Louis.
Classic Garbage In, Garbage Out
LOL. Actually, I could be related to the McCoys of the
Hatfields and McCoys - there's a chunk of my great great
great great grandfather's life we don't know much about
(other than that he _was_ fleeing the hangman), it's not
impossible he was part of the group that came to the US
in the late 1700s.
You make a good point about using Wikipedia as a pointer
to more detailed references, altho again you have to use
some judgement as to the credibility of the reference.
But most Wikipedia articles get corrected pretty promptly
when garbage is added. You can look at the history of an
article, and see where people have added (either by intent
or by error) bogus information, and, often only a few hours
later, where it was taken out.
Depends on the glue. For epoxy, definately so. For common
yellow woodworking glue, no, at least not with any kind of
hand-tightened clamp. For other kinds of glues, I dunno.
It is, of course, very possible to not put enough glue in
the joint in the first place, which would have the symptom
On Thu, 24 Dec 2015 19:31:37 -0000 (UTC), John McCoy
I had heard in an online video once about over clamping problems, that
they were going to do some tests of get info, but it never came about
to my knowledge.
I had a couple half lap joints come apart which added to my wondering,
but in the end I realized it was sloppy work on my part. Too loose a
joint. I learned the hard way that if I cut a joint best to assemble
in right then. Or store up some wood ahead of time.
I made a could half lap joints on 2 X 4's to put my metal Craftsman
Cabinets on, checked out the fit and it was just a tad tighter than I
figured it should be, just to get glue in there. Next morning I dbl
Checked the fit and both were now a tad loose and when I added glue
they really got sloppy. When the joints dried I could see a couple
gaps. GRRRR. And the joint seemed like it was the easiest to do in the
I am great with sheet metal stuff, but wood working is far different.
I would apprentice myself in a shop, for free, just to learn good
habits and make some of this stuff natural to me. (and for now at
least, I don't even mind sanding. :) )
Yeah, for common wood glues you need wood-to-wood contact
for the glue to make a strong bond. The exception is epoxy,
which will fill a gap (indeed, if you add sawdust or Lew's
favorite microballoons (*) to make a putty, you can fill
gaps measured in inches with epoxy).
Note that, while squeezing glue out due to clamping isn't
an issue, scraping all the glue off during assembly is,
especially when doing things like putting a tenon into a
mortise. It is possible to make a joint too tight.
Construction lumber is a pain, because it changes shape
and twists and what-not whenever you cut it. I'd probably
have screwed something like that together instead of glue.
Yeah, I get that from watching my buddy the machinist.
Seems like the big differences are that metal doesn't
compress (so you can't make a joint a tad tight and
push it together), and wood doesn't let you add filler
(unlike welding metal).
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