Coat copper head gaskets with Permatex #2

[Nomen Nescio]

For a perfect seal, coat copper head gaskets with Permatex #2.

Do not worry about heat conductivity or gas leakage. Here's why:

Where there is true metal-to-metal contact between head, block and gasket,
Permatex will be excruded and metal-to-metal contact will be established.
Heat conductivity will be the same as if Permatex #2 was never applied.

Where there are irregularities in the metal surfaces, the Permatex will
block gas leakage 100%. Copper has limited conformability. Say there is a
surface that is 0.002 inch low and it spans one inch. The chances are the
copper gasket will not conform. But Permatex #2 will fill in the gap. You
might ask how it will seal against, say 1000 psi when the cylinder fires?
Do the math. 0.002 x 1.000 equals .002 square inch x 1000 psi equals two
pounds. TWO POUNDS is all the pressure the Permatex seal has to withstand.
It does that graciously. As for the heat, the heat wave cools dramatically
after as little as 0.1 inch penetration into the gap.

Coat both sides of the gasket with Permatex #2. The best way is to use a
printer's roller, but the finger will suffice. I recommend #2 because it
is flexible enough to maintain a seal as the head contracts and expands
with heat.

Nomen the Megaposter

[oskar]

Post by Nomen Nescio
For a perfect seal, coat copper head gaskets with Permatex #2.

Anybody dumb enough to use a solid copper head gasket in these days of
excellent composition head gaskets and raised ridge head gaskets and
o-ring seals is dumb enough to follow Nomen Nescio's idiotic tips.

[les]

Post by oskar

Post by Nomen Nescio
For a perfect seal, coat copper head gaskets with Permatex #2.

Anybody dumb enough to use a solid copper head gasket in these days of
excellent composition head gaskets and raised ridge head gaskets and
o-ring seals is dumb enough to follow Nomen Nescio's idiotic tips.

Anyone idiot enough to rule out copper head gaskets on any and all bikes is
just as bad. Some old bikes used copper, and unless you can show me
otherwise, it's all that's available for them still. Nothing wrong with a
head gasket that can be annealed and reused...

Les

[oskar]

Post by les

Post by oskar
Anybody dumb enough to use a solid copper head gasket in these days of
excellent composition head gaskets and raised ridge head gaskets and
o-ring seals is dumb enough to follow Nomen Nescio's idiotic tips.

Anyone idiot enough to rule out copper head gaskets on any and all bikes is
just as bad. Some old bikes used copper, and unless you can show me
otherwise, it's all that's available for them still. Nothing wrong with a
head gasket that can be annealed and reused...

Oh, you think you're talking to Nomen Nescio's idiot identical twin
brother, huh?

There's nothing "right" about a flat, plain metal gasket that spreads
out clamping force too much. Applying a sealing goop to such a surface
is just an exercise in futility. The gasket is going to leak sooner or
later.

Been there, done that. 1968 Yamaha 250cc single cylinder 2-stroke came
with a flat copper gasket. It leaked. Yamaha tech reps recommended
annealing the flat copper gasket in an oven and applying various
compounds, like Indian Head gasket shellac and red hematite goop. That
did NOT work.

Yamaha *immediately* moved on to improved sealing systems, which
involved
copper gaskets with raised ridges that would act as o-rings when they
mated with a groove machined in the head. The new gasket was also
effective with the original, ungrooved head. The raised ridges would
crush more, but they would seal.

And, how do spark plugs seal 900psi combustion gasses against leakage?

Two ways. One is by using a crushable metal gasket, the other is by a
tapered spark plug that seals by increasing contact pressure in a small
area.

Did you ever hear of o-ringing a head to increase the contact pressure
between
the cylinder and the head by cutting a groove and installing a soft
wire ring in the groove? Specialty machine shops who have worked on
older machines modified with high compression pistons would understand
o-ringing.

Another way to do it is with a flat copper ring in a wider flat
channel. That increases the pressure per unit area too.

Another way is to design a labyrinth seal system into the head and
cylinder. Bultaco used such a system on their 2-strokes.

I will never forget when I was helping a kid down the street get his
175cc Bultaco running after he tried to re-ring it himself. The Bultaco
shop mechanic recommended that he lap the labyrinth seal by putting a
little valve grinding compound on the parts and rotating them to lap
the surfaces. The kid thought that the shop mechanic meant that valve
grinding compound would make a better seal, so he smeared the compound
on and bolted the head to the engine!

He couldn't get the engine started, so he asked me for help. We took
the head off, and
when I saw the valve grinding compound, I asked him what the story was.
He told me what he understood the shop mechanic to be saying. No way,
dude!

We pulled the cylinder off the engine and lapped the parts together and
I looked at the paper cylinder base gasket. It had NO cutouts for the
lower entrance to the transfer passages. Apparently, Bultaco
anticipated that any mechanic working on a Bultaco would know how a
2-stroke engine worked and would know to finish the gasket by cutting
the transfer passage entrance area out.

You want to discuss methods of holding in pressure at high
temperatures, I'll tell you about some of my aerospace experience.

I worked in an engineering lab, doing qualification tests on
high-temperature, high-pressure pneumatic ducting and other pneumatic
components for the F-15, when the system was manufactured under license
by a Japanese tire company.

I needed to apply steady pressures on the order of 400 pounds to parts
which had incidental clamped flanges with flat gaskets between them in
order to do pressure decay tests at 750 degrees F. in a gas-fired oven.

We weren't much concerned with the clamped flanges, as I recall, we
didn't even have any official gaskets. I had to improvise a sealing
system that would hold the pressure long enough to run my leakage rate
and pressure decay rate tests.

My crude flat gaskets always leaked. By now you know why. I tried high
temperature rubber o-rings and they leaked too. In order to qualify the
parts, I had to come up with another solution. It was a tapered metal
plug, which I clamped between the flanges. The tapered plug increased
the point force per unit area of the sealing surface and the parts
passed the specified tests.

The ducting system had to be made in many short pieces, with built-in
metal bellows to allow for thermal expansion in operation. Hot
compressed gasses would be bled off the jet engine and would go through
the ducting to whatever pneumatic components were being supplied.

So there were many sections of ducting that had to be clamped together.
Without gaskets.

How did the ends of the ducts seal in hot, high pressure gasses with no
gasket whatever? The flanges on the ends of the ducts were not flat,
they were slightly curved.

This slight curvature increased the pressure per unit area of contact
and made an effective seal.

Got any more questions for old idiots, such as myself?

[les]

Post by oskar

Post by les

Post by oskar
Anybody dumb enough to use a solid copper head gasket in these days
of excellent composition head gaskets and raised ridge head gaskets
and o-ring seals is dumb enough to follow Nomen Nescio's idiotic
tips.

Anyone idiot enough to rule out copper head gaskets on any and all
bikes is just as bad. Some old bikes used copper, and unless you can
show me otherwise, it's all that's available for them still. Nothing
wrong with a head gasket that can be annealed and reused...

Oh, you think you're talking to Nomen Nescio's idiot identical twin
brother, huh?

No, but someone that doesn't realize copper works just fine for some
applications. I also know enough to realize Nomen Nescio is the name
provided when using anonymous remailers.

Post by oskar
There's nothing "right" about a flat, plain metal gasket that spreads
out clamping force too much. Applying a sealing goop to such a surface
is just an exercise in futility. The gasket is going to leak sooner or
later.

I do agree that applying sealing goop is a mistake. Making sure the surfaces
are not warped and torquing properly will allow it to seal just fine.

Post by oskar
Been there, done that. 1968 Yamaha 250cc single cylinder 2-stroke came
with a flat copper gasket. It leaked. Yamaha tech reps recommended
annealing the flat copper gasket in an oven and applying various
compounds, like Indian Head gasket shellac and red hematite goop. That
did NOT work.

That'll make it leak quicker, IMO.

Post by oskar
Yamaha *immediately* moved on to improved sealing systems, which
involved
copper gaskets with raised ridges that would act as o-rings when they
mated with a groove machined in the head. The new gasket was also
effective with the original, ungrooved head. The raised ridges would
crush more, but they would seal.

That'd be a good alternative, if offered for all bikes. It's not though, and
the original type flat copper gaskets work just fine.

Post by oskar
And, how do spark plugs seal 900psi combustion gasses against leakage?
Two ways. One is by using a crushable metal gasket, the other is by a
tapered spark plug that seals by increasing contact pressure in a
small area.

Apples and oranges.

Post by oskar
Did you ever hear of o-ringing a head to increase the contact pressure
between
the cylinder and the head by cutting a groove and installing a soft
wire ring in the groove? Specialty machine shops who have worked on
older machines modified with high compression pistons would understand
o-ringing.

Sure, that'd be a great idea on an engine where compression is being bumped.
Not always needed on a stock engine though.

Post by oskar
Another way to do it is with a flat copper ring in a wider flat
channel. That increases the pressure per unit area too.
Another way is to design a labyrinth seal system into the head and
cylinder. Bultaco used such a system on their 2-strokes.
I will never forget when I was helping a kid down the street get his
175cc Bultaco running after he tried to re-ring it himself. The
Bultaco shop mechanic recommended that he lap the labyrinth seal by
putting a little valve grinding compound on the parts and rotating
them to lap the surfaces. The kid thought that the shop mechanic
meant that valve grinding compound would make a better seal, so he
smeared the compound on and bolted the head to the engine!
He couldn't get the engine started, so he asked me for help. We took
the head off, and
when I saw the valve grinding compound, I asked him what the story
was. He told me what he understood the shop mechanic to be saying. No
way, dude!
We pulled the cylinder off the engine and lapped the parts together
and I looked at the paper cylinder base gasket. It had NO cutouts for
the lower entrance to the transfer passages. Apparently, Bultaco
anticipated that any mechanic working on a Bultaco would know how a
2-stroke engine worked and would know to finish the gasket by cutting
the transfer passage entrance area out.
You want to discuss methods of holding in pressure at high
temperatures, I'll tell you about some of my aerospace experience.
I worked in an engineering lab, doing qualification tests on
high-temperature, high-pressure pneumatic ducting and other pneumatic
components for the F-15, when the system was manufactured under
license by a Japanese tire company.
I needed to apply steady pressures on the order of 400 pounds to parts
which had incidental clamped flanges with flat gaskets between them in
order to do pressure decay tests at 750 degrees F. in a gas-fired oven.
We weren't much concerned with the clamped flanges, as I recall, we
didn't even have any official gaskets. I had to improvise a sealing
system that would hold the pressure long enough to run my leakage rate
and pressure decay rate tests.
My crude flat gaskets always leaked. By now you know why. I tried high
temperature rubber o-rings and they leaked too. In order to qualify
the parts, I had to come up with another solution. It was a tapered
metal plug, which I clamped between the flanges. The tapered plug
increased the point force per unit area of the sealing surface and
the parts passed the specified tests.

Sounds like the flanges should have been RTJ, using a metal ring in the
joint for sealing. Commonly used in natural gas systems where pressures are
going to be in excess of 2,000 PSI.

Post by oskar
The ducting system had to be made in many short pieces, with built-in
metal bellows to allow for thermal expansion in operation. Hot
compressed gasses would be bled off the jet engine and would go
through the ducting to whatever pneumatic components were being
supplied.
So there were many sections of ducting that had to be clamped
together. Without gaskets.
How did the ends of the ducts seal in hot, high pressure gasses with
no gasket whatever? The flanges on the ends of the ducts were not
flat, they were slightly curved.
This slight curvature increased the pressure per unit area of contact
and made an effective seal.
Got any more questions for old idiots, such as myself?

Yes, have you worked on all makes and models of old bikes? Are you familar
with what head gaskets are available for them? Several use copper, it works
just fine for them. Leaking head gaskets are not a big problem.

Les

[terrapin]

Post by Nomen Nescio
Do the math. 0.002 x 1.000 equals .002 square inch x 1000 psi equals two
pounds. TWO POUNDS is all the pressure the Permatex seal has to withstand.

1000 psi is still the pressure the Permatex seal has to withstand.
"Two pounds" is a force, not a pressure.

[R. Pierce Butler]

Post by Nomen Nescio
For a perfect seal, coat copper head gaskets with Permatex #2.
Where there is true metal-to-metal contact between head, block and
gasket, Permatex will be excruded and metal-to-metal contact will be
established. Heat conductivity will be the same as if Permatex #2 was
never applied.
Where there are irregularities in the metal surfaces, the Permatex will
block gas leakage 100%. Copper has limited conformability. Say there
is a surface that is 0.002 inch low and it spans one inch. The chances
are the copper gasket will not conform. But Permatex #2 will fill in
the gap. You might ask how it will seal against, say 1000 psi when the
cylinder fires? Do the math. 0.002 x 1.000 equals .002 square inch x
1000 psi equals two pounds. TWO POUNDS is all the pressure the Permatex
seal has to withstand. It does that graciously. As for the heat, the
heat wave cools dramatically after as little as 0.1 inch penetration
into the gap.
Coat both sides of the gasket with Permatex #2. The best way is to use
a printer's roller, but the finger will suffice. I recommend #2 because
it is flexible enough to maintain a seal as the head contracts and
expands with heat.
Nomen the Megaposter

Nomen is the king of misinformation. Permatex #2 is good only to 400
degrees. After that it burns. It is not always flexible as it
eventually dries hard as a rock. Using it on a head gasket is inviting
trouble.

I like his funny math. With logic and math like that, who needs a head
gasket? Put some Bounty paper towel in as a head gasket. If it can hold
up a cup of coffee when wet, it can hold two lbs when dry right?

pierce