A
amphiguru
Guest
Professional welding of steel panels is the only secure method to
repair the Amphicar in its original design.
Let's look at the following concepts and experiences: (1)
coefficient of expansion, (2) passive lifetime of product, (3)
active lifetime of product, (4) real world examples.
Coefficient of expansion
The movement of heat into and out of steel is not compatible with a
resin product. Steel heats and cools much more rapidly. In time,
the "expansion friction" will cause separation. Think of the 150 to
200 degree inside engine compartment temperatures on one side, and
60 degree lake water on the other. Throw in cold wave water, road
rain, and years of launching, and you see the picture.
Passive lifetime
Organic new products made of rubber, plastic, cloth and wood last
much longer than those in an active lifetime. If new old stock
organics were stored in nitrogen gas, they would approach original,
new service life. Obviously, the best we can hope for are parts
that are sealed in plastic bags in a dark cool area with 50%
humidity.
Active lifetime
As we use our Amphicars, the organic parts: propellers, lenses,
seals, mounts, hoses tires, etc., are exposed to physical movement
within a world filled with ultraviolet light, constantly changing
temperature extremes, engine oil, hypoid gear oil, brake fluid, anti-
freeze, and the normal oxidation from oxygen and ozone in our
atmosphere.
Real world examples
Forget about all this chemical mumbo jumbo. What we all care about
are the parts and body work on our cars. So, let's look at some
examples.
1. Taillight lens - Over time, the red color bleaches from dark red
to pink. The resin itself developes "haze cracks". Ultimately, the
lens shatters from the slightest touch.
2. Propellers - Hold an old but good working propeller up to the
sunlight. Sooner or later, you will see the same "haze cracks".
Eventually, the "active lifetime" is exceeded and the propeller
fails with one blade breaking off.
3. Original Amphicar bilge coatings - The constant heat cycling of
cold lake water mixed with hot oils, residual anti-freeze, etc.,
sooner or later "lifts" the original, soft epoxy coating off the
metal floor. Each car is different due to usage. However, you will
never see actual steel parts like fenders "lift off" bodies, or
brackets. the engine metals don't separate. Only where they meet
gaskets, i.e., organic parts, do they develope leaks and failures.
4. Oil cooler hoses - When new, they are flexible, pliable, and
absorb the movement of the engine on its mounts. About six years
ago, the "active lifetime" of originally installed hoses produced a
failure rate of epic proportions. Almost daily the phone calls were
the same, "My hose broke, spraying oil on my engine and convertible
top. What happened?" The organics of the hose were as brittle as
glass. Since the oil cooler doesn't move and the engine does, the
rock hard hoses split open. Again it's the repeated hot/cold
cycling of the oil in an organic hose.
5. Fan belts - Old belts are a disaster. To see how fragile they
become, fold that old spare belt over backwards on itself. It will
split almost in two pieces.
6. Shock absorbers - Over time, the internal rubber extension stops
turn to a gel inside the shock tubes. Then the shocks hang too low,
causing the drive shafts to rub the tunnels when the wheels hang
down in the water.
The real question which needs a reliable answer is: How many active
hot/cold, etc. cycles can these glues take before separation
occurs? Then it's time to re-glue. So, from my experience, I'll
stay with steel.
Hugh
P.S. Ever notice the warning label of the use of those plastic, TV
dinner trays? You get only ONE active trip from freezer to boiling
hot. GOOD LUCK!
repair the Amphicar in its original design.
Let's look at the following concepts and experiences: (1)
coefficient of expansion, (2) passive lifetime of product, (3)
active lifetime of product, (4) real world examples.
Coefficient of expansion
The movement of heat into and out of steel is not compatible with a
resin product. Steel heats and cools much more rapidly. In time,
the "expansion friction" will cause separation. Think of the 150 to
200 degree inside engine compartment temperatures on one side, and
60 degree lake water on the other. Throw in cold wave water, road
rain, and years of launching, and you see the picture.
Passive lifetime
Organic new products made of rubber, plastic, cloth and wood last
much longer than those in an active lifetime. If new old stock
organics were stored in nitrogen gas, they would approach original,
new service life. Obviously, the best we can hope for are parts
that are sealed in plastic bags in a dark cool area with 50%
humidity.
Active lifetime
As we use our Amphicars, the organic parts: propellers, lenses,
seals, mounts, hoses tires, etc., are exposed to physical movement
within a world filled with ultraviolet light, constantly changing
temperature extremes, engine oil, hypoid gear oil, brake fluid, anti-
freeze, and the normal oxidation from oxygen and ozone in our
atmosphere.
Real world examples
Forget about all this chemical mumbo jumbo. What we all care about
are the parts and body work on our cars. So, let's look at some
examples.
1. Taillight lens - Over time, the red color bleaches from dark red
to pink. The resin itself developes "haze cracks". Ultimately, the
lens shatters from the slightest touch.
2. Propellers - Hold an old but good working propeller up to the
sunlight. Sooner or later, you will see the same "haze cracks".
Eventually, the "active lifetime" is exceeded and the propeller
fails with one blade breaking off.
3. Original Amphicar bilge coatings - The constant heat cycling of
cold lake water mixed with hot oils, residual anti-freeze, etc.,
sooner or later "lifts" the original, soft epoxy coating off the
metal floor. Each car is different due to usage. However, you will
never see actual steel parts like fenders "lift off" bodies, or
brackets. the engine metals don't separate. Only where they meet
gaskets, i.e., organic parts, do they develope leaks and failures.
4. Oil cooler hoses - When new, they are flexible, pliable, and
absorb the movement of the engine on its mounts. About six years
ago, the "active lifetime" of originally installed hoses produced a
failure rate of epic proportions. Almost daily the phone calls were
the same, "My hose broke, spraying oil on my engine and convertible
top. What happened?" The organics of the hose were as brittle as
glass. Since the oil cooler doesn't move and the engine does, the
rock hard hoses split open. Again it's the repeated hot/cold
cycling of the oil in an organic hose.
5. Fan belts - Old belts are a disaster. To see how fragile they
become, fold that old spare belt over backwards on itself. It will
split almost in two pieces.
6. Shock absorbers - Over time, the internal rubber extension stops
turn to a gel inside the shock tubes. Then the shocks hang too low,
causing the drive shafts to rub the tunnels when the wheels hang
down in the water.
The real question which needs a reliable answer is: How many active
hot/cold, etc. cycles can these glues take before separation
occurs? Then it's time to re-glue. So, from my experience, I'll
stay with steel.
Hugh
P.S. Ever notice the warning label of the use of those plastic, TV
dinner trays? You get only ONE active trip from freezer to boiling
hot. GOOD LUCK!
