I was reading about the grading of steel bolts
(http://www.sizes.com/tools/bolts_SAEtork.htm.) At the end it made
this interesting statement:

"It isn't always a good idea to replace a bolt with a stronger one.
Some bolts are deliberately chosen so that they are weak enough to
fail before the stress or strain damages some more expensive or
critical part of the equipment. For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true? I recall reading on this NG that regular wood glue
forms a bond stronger than sold hardwood and when tested the wood
breaks near the joint before the joint separates.

Thanks,
Michael

"Michael Press" wrote in message
...

---snip-----
critical part of the equipment. For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true? I recall reading on this NG that regular wood glue
forms a bond stronger than sold hardwood and when tested the wood
breaks near the joint before the joint separates.

I have seen pictures of tests done with glue and various joints on this NG
but don't have any reference to that study handy. However, this individual
has an opinion worth noting.
http://atos.stirlingprop.com/kbase/HOTHIDEGLUE.htm

Larry

The July/August Handy magazine just did an article on glues.
They did a review on everything from plain old elmer's,
Tightbonds, Epoxies, hot-melts, Eurathanes, etc....
They stated that most glues (other than hobby glues)
have a rated shear resistance of 2000-4000 psi, which is
greater than most wood species and that some epoxies go
8000 psi or higher.

Joey in Chesapeake
"Michael Press" wrote in message
...

I was reading about the grading of steel bolts
(http://www.sizes.com/tools/bolts_SAEtork.htm.) At the end it made
this interesting statement:

"It isn't always a good idea to replace a bolt with a stronger one.
Some bolts are deliberately chosen so that they are weak enough to
fail before the stress or strain damages some more expensive or
critical part of the equipment. For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true? I recall reading on this NG that regular wood glue
forms a bond stronger than sold hardwood and when tested the wood
breaks near the joint before the joint separates.

Thanks,
Michael

"Michael Press" wrote ...
critical part of the equipment. For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true? I recall reading on this NG that regular wood glue
forms a bond stronger than sold hardwood and when tested the wood
breaks near the joint before the joint separates.

There is no way to really quantify what "Stronger than the wood itself" or
"weaker..." means. I have seen several articles that try to explain it but
you can't really put a number on it. No furniture maker will consciously
make a joint that has a weak spot in case of later breakage. You try to
make the joint as strong as possible so it will never break. To do that you
need a properly executed joint and a properly applied adhesive. Any study
you can find will show pictures of joints (one in FWW several years back
comes to mind) that failed where the wood around the joint broke instead of
the glueline. It seems to me that common sense would indicate that the glue
was not the weakest point in the equation. Of course it also means that
once you have reached the point where the surrounding wood fails before the
glueline, that requirement for additional strength is debatable.

--

Cheers,
Howard

----------------------------------------------------------
Working wood in New Jersey -
Visit me in the woodshop - www.inthewoodshop.org

"Michael Press" wrote in message
...

For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."


I don't think this is accurate. I can't think of an instance where
something is designed in woodworking to fail. The idea is that something
should be built so that it will never fail. It is probably a valid point
when dealing with metal mechanical things such as engines, transmissions,
etc. I don't believe the same philosophy has any place in the construction
of an endtable.

Frank

Mon, Jun 28, 2004, 5:41pm (EDT+4) (Lawrence=A0L'Hote)
says:
snip However, this individual has an opinion worth noting.
http://atos.stirlingprop.com/kbase/HOTHIDEGLUE.htm

I think my favorite part is where he goes on about the glue being
weaker then the wood, even tho some wood will go with the glue when a
joint fails, then says that means nothing. Amazing. Absolutely
amazing. I stopped reading about then.


JOAT
That the peope have a right to bear arms for the defense of themselves
and the state.
- Pennsylvania Constitution of 1776

"Frank Ketchum" wrote in message
hlink.net

I can't think of an instance where
something is designed in woodworking to fail. The idea is that something
should be built so that it will never fail. It is probably a valid point
when dealing with metal mechanical things such as engines, transmissions,
etc. I don't believe the same philosophy has any place in the construction
of an endtable.

Quite right.

PVA is a release agent when mixed with almost anything else except
water. I believe meths is used with it in fibreglass molds. Any glue
joint will fail too where one or both sides is rubbed down with a damp
cloth and the pores are full of water when the glue is applied. These
are not engineered devices but poor practice.




--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

On Mon, 28 Jun 2004 17:10:36 -0400, (J T)
wrote:

Mon, Jun 28, 2004, 5:41pm (EDT+4) (Lawrence*L'Hote)
says:
snip However, this individual has an opinion worth noting.
http://atos.stirlingprop.com/kbase/HOTHIDEGLUE.htm

I think my favorite part is where he goes on about the glue being
weaker then the wood, even tho some wood will go with the glue when a
joint fails, then says that means nothing. Amazing. Absolutely
amazing. I stopped reading about then.

I thought he brought up some interesting points. I haven't yet used
hide glue, but I believe I'll dig out that bag that's been gathering
dust on the back shelf for a little research.

JP

On Mon, 28 Jun 2004 21:20:48 +0000 (UTC), "Michael Mcneil"
wrote:

"Frank Ketchum" wrote in message
thlink.net

I can't think of an instance where
something is designed in woodworking to fail.

Shoji screens are made with rice glue so that they can be easily
knocked apart, repaired and reassembled.

JP

The idea is that something
should be built so that it will never fail. It is probably a valid point
when dealing with metal mechanical things such as engines, transmissions,
etc. I don't believe the same philosophy has any place in the construction
of an endtable.

Quite right.

PVA is a release agent when mixed with almost anything else except
water. I believe meths is used with it in fibreglass molds. Any glue
joint will fail too where one or both sides is rubbed down with a damp
cloth and the pores are full of water when the glue is applied. These
are not engineered devices but poor practice.

The key part of this information is "expensive or critical part of the
equipment". Furniture does not generally fall into these categories. I
can't think of a reason save movie break-apart furniture, where a joint
would be designed to fail. Well maybe some IKEA stuff!

Dave


"Michael Press" wrote in message
...

I was reading about the grading of steel bolts
(http://www.sizes.com/tools/bolts_SAEtork.htm.) At the end it made
this interesting statement:

"It isn't always a good idea to replace a bolt with a stronger one.
Some bolts are deliberately chosen so that they are weak enough to
fail before the stress or strain damages some more expensive or
critical part of the equipment. For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true? I recall reading on this NG that regular wood glue
forms a bond stronger than sold hardwood and when tested the wood
breaks near the joint before the joint separates.

Thanks,
Michael



Posted Via Usenet.com Premium Usenet Newsgroup Services
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It's pretty much a non issue. All modern wood glues are stronger then the
wood, as is some not so modern ones so, from that point you would have to
hunt around for some glue that is weaker then the wood but strong enough to
withstand the forces it will encounter and I don't think fish or vegetable
glue will cut it.

To look at it in another way, unless you are talking balsa wood models, wood
it's self is pretty sturdy stuff and with properly made joints, if someone
is going too, in the course of normal use, bang it around badly enough to
break it either at the joint or the grain maybe it probably shouldn't have
been made of wood to start with or they shouldn't have been allowed near it.

Lastly, we aren't talking, say a crankshaft breaking under transmitted
stress we're talking wood that can be glued back up again.

I've had to repair glue joint failures and wood grain failures. I prefer the
wood grain failures, the wood goes back together easily and seamlessly where
as a failed glue line is usually a raggedy ass affair that always seem to
end up as an obvious repair.

In short, it's horse pucky.

..



--
Mike G.
Heirloom Woods

www.heirloom-woods.net
"Michael Press" wrote in message
...

I was reading about the grading of steel bolts
(http://www.sizes.com/tools/bolts_SAEtork.htm.) At the end it made
this interesting statement:

"It isn't always a good idea to replace a bolt with a stronger one.
Some bolts are deliberately chosen so that they are weak enough to
fail before the stress or strain damages some more expensive or
critical part of the equipment. For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true? I recall reading on this NG that regular wood glue
forms a bond stronger than sold hardwood and when tested the wood
breaks near the joint before the joint separates.

Thanks,
Michael

On Mon, 28 Jun 2004 13:25:45 -0400, Michael Press
vaguely proposed a theory
.......and in reply I say!:

remove ns from my header address to reply via email

For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."

Is this true?

No. It's crap. Glues are stronger than wood. Most joints involve the
wood of one part intruding into the other part, specifically so that
the wood has to break to break the joint.

"Frank Ketchum" wrote in message
hlink.net...

"Michael Press" wrote in message
...

For the same reason, in making
furniture cabinetmakers use glues that are weaker than wood. That
way, if the furniture is overloaded, the joints break. It is much
easier to reglue a broken joint than to replace a piece of broken
wood."


I don't think this is accurate. I can't think of an instance where
something is designed in woodworking to fail. The idea is that something
should be built so that it will never fail. It is probably a valid point
when dealing with metal mechanical things such as engines, transmissions,
etc. I don't believe the same philosophy has any place in the
construction
of an endtable.

many things have 'sacrificial' parts or points of known failure. electronic
circuits have a fuse which is essentially a wire that burns up. car engines
have plugs in them so if they overheat the plugs pop before the block
cracks. boat owners toss zinc over the side with a wire attached so it
corrodes and not the boat. the company that makes my electric toothbrush
thoughtfully makes the plastic on the replacable brushes much softer than
the expensive handle and will in fact repeatadly crack in the same place if
over tightened, trust me on this one g

but for an end table, i agree. it doesnt apply.

randy

"xrongor" wrote in message
news
Snip

car engines have plugs in them so if they overheat the plugs pop before
the block
cracks.

They pop out to prevent damage but not because of overheating.
Those plugs are known as FREEZE plugs. If the cooling system water in the
engine block freezes the expanding ice will pop out the plugs to help
prevent damage to the engine.
The radiator cap is the safety valve for an overheating cooling system, not
the freeze plugs.

On Mon, 28 Jun 2004 15:47:01 -0700, TeamCasa wrote:
The key part of this information is "expensive or critical part of the
equipment". Furniture does not generally fall into these categories. I
can't think of a reason save movie break-apart furniture, where a joint
would be designed to fail. Well maybe some IKEA stuff!

Dave

"Breakaways" are generally made without glue and with rather loose
joinery all 'round.

Take a gander at WWE's chairs: They're a design that holds together
when weight is applied (they can be sat upon) but fall apart fairly
easily.

Casework is often made of styrene foam.

"Leon" wrote in message
m...

"xrongor" wrote in message
news
Snip

car engines have plugs in them so if they overheat the plugs pop before
the block
cracks.

They pop out to prevent damage but not because of overheating.
Those plugs are known as FREEZE plugs. If the cooling system water in the
engine block freezes the expanding ice will pop out the plugs to help
prevent damage to the engine.
The radiator cap is the safety valve for an overheating cooling system,
not
the freeze plugs.

ya freeze. it was late.

nonetheless, what good is the radiator cap if all the coolant is missing and
the temp sensor doesnt work.... the plugs will help with that too. my dad
grossly overheated a slant 6 in that condition and plugs popped.

randy

In article ,
Leon wrote:

"xrongor" wrote in message
news
Snip

car engines have plugs in them so if they overheat the plugs pop before
the block
cracks.

They pop out to prevent damage but not because of overheating.
Those plugs are known as FREEZE plugs. If the cooling system water in the
engine block freezes the expanding ice will pop out the plugs to help
prevent damage to the engine.
The radiator cap is the safety valve for an overheating cooling system, not
the freeze plugs.



I was going to let this OT pass, but, though they are commonly
referred to as freeze plugs, the technical term IIRC is welch plugs.
They are NOT designed to protect the block or other casting from
freezing, they are simply required as part of the casting process.
--

Larry Wasserman Baltimore, Maryland

"xrongor" wrote in message
...
nonetheless, what good is the radiator cap if all the coolant is missing
and
the temp sensor doesnt work.... the plugs will help with that too. my
dad
grossly overheated a slant 6 in that condition and plugs popped.


Modern cars, built since the mid 70's, and I realize the old Dodge slant 6
and been around longer than that, have coolant recovery tanks. As the
temperature of the coolant cools inside the cooling system the coolant is
sucked back into the radiator through the radiator cap and back into the
radiator. The radiator cap is a 2 way valve. When pressure builds up high
enough because of temperature the radiator cap lets water bypass it and into
the hose going into the coolant recovery tank. When the coolant cools and
contracts, the coolant passes back through the cap and into the radiator.
If the freeze plugs indeed pop out because of overheating, you probably had
a number of problems with that engine. #1, you temp sensor did not work
properly, probably too much corrosion built up for it to get a correct
reading or, there was an air pocket and the coolant was not submerged in the
coolant. #2, the radiator cap did not work properly or was one with too
high of a pressure setting for that car. #3, since the freeze plugs popped
out, the engine over heated and the temp gauge did not work, I suspect a
rusted out cooling system and the freeze plugs were probably about rusted
out anyway.

"Lawrence Wasserman" wrote in message
...


I was going to let this OT pass, but, though they are commonly
referred to as freeze plugs, the technical term IIRC is welch plugs.
They are NOT designed to protect the block or other casting from
freezing, they are simply required as part of the casting process.

This is correct. But they are referred to as freeze plugs by GM at least in
the 70's and 80's when I was Service manager of a General Motors dealer.



--

Larry Wasserman Baltimore, Maryland

Tue, Jun 29, 2004, 1:34pm (EDT+4) (Leon)
says:
snipThose plugs are known as FREEZE plugs. If the cooling system water
in the engine block freezes the expanding ice will pop out the plugs to
help prevent damage to the engine. snip

Not quite. "Freeze plug" holes in the engine block are actually
used to empty out sand, used during casting.

JOAT
When you're up to your ass in alligators, today is the first day of the
rest of your life.
- Archchancellor Mustrum Ridcully, UU

Really a dual purpose part. As you indicated, to close an opening that is
intended to facilitate the manufacture of the block and,

Definition: An expansion plug located in the side of an engine block that is
supposed to protect the block against freeze damage. Water expands when it
turns to ice, and if the coolant doesn't have enough antifreeze protection
it can freeze and crack the engine block. The freeze plugs (there are
several) are supposed to pop out under such conditions to relieve the
pressure on the block. Freeze plugs can often be a source of troublesome
leaks as a result of internal cooling system corrosion. Ease of replacement
depends on accessibility.

On Tue, 29 Jun 2004 18:57:11 -0400, (J T)
vaguely proposed a theory
.......and in reply I say!:

remove ns from my header address to reply via email


When you're up to your ass in alligators, today is the first day of the
rest of your life.
- Archchancellor Mustrum Ridcully, UU

I would have said "last day"....

Wed, Jun 30, 2004, 8:29am (EDT+12) (Old=A0Nick)
says:
I would have said "last day"....

But, if you believe in reincarnation...

JOAT
When you're up to your ass in alligators, today is the first day of the
rest of your life.
- Archchancellor Mustrum Ridcully, UU