blow-up (testing)

[mark grady]

{snip}

> Inspected my cones tonight and still cannot tell if they are aluminum or
> plastic. they are black but I really don't want to scrape them
> for fear of
> losing the protection of the covering if they are aluminum.

Take your volt-ohm meter with sharp probes, set on continuity or a low ohm
scale and stick it to it.
You'll know right away if its plastic or not. If you don't have a VOM, use a
12 volt light, a sharp nail and make the cone the ground for the circuit.

+12 volts-----------bulb--------------------->
nail or sharp point

First touch the nail or sharp point to a known good ground to make sure your
light works.
Then push into the cone with the point. Light goes on, metal cone. Light
stays out, plastic.

I think Rick Staples already suggested this, but this testing can be done by
anyone who wants to know.

Put a dab of silicone or fingernail polish over the hole your test leaves in
the powder coat to prevent further deterioration. I always wear the new
Covergirl nail slicks when I'm out on the town.

Regarding plastic good or bad, exploding fact or myth, I've never known GM
to undertake a recall/field upgrade if there wasn't a good reason. I'd
change 'em over taking a chance.

Mark

 

[thomas g. warner]

I will try it but if the cones are coated with a plastic than they will more
than likely not conduct electricity to the chassis.

Was there actually a recall of the plastic cones. If so shouldn't it still
be in effect?

>{snip}
>
>> Inspected my cones tonight and still cannot tell if they are aluminum or
>> plastic. they are black but I really don't want to scrape them
>> for fear of
>> losing the protection of the covering if they are aluminum.
>
>Take your volt-ohm meter with sharp probes, set on continuity or a low ohm
>scale and stick it to it.
>You'll know right away if its plastic or not. If you don't have a VOM, use a
>12 volt light, a sharp nail and make the cone the ground for the circuit.
>
>+12 volts-----------bulb--------------------->
> nail or sharp point
>
>First touch the nail or sharp point to a known good ground to make sure your
>light works.
>Then push into the cone with the point. Light goes on, metal cone. Light
>stays out, plastic.
>
>I think Rick Staples already suggested this, but this testing can be done by
>anyone who wants to know.
>
>Put a dab of silicone or fingernail polish over the hole your test leaves in
>the powder coat to prevent further deterioration. I always wear the new
>Covergirl nail slicks when I'm out on the town.
>
>Regarding plastic good or bad, exploding fact or myth, I've never known GM
>to undertake a recall/field upgrade if there wasn't a good reason. I'd
>change 'em over taking a chance.
>
>Mark
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach

 

[mark grady]

> I will try it but if the cones are coated with a plastic than
> they will more
> than likely not conduct electricity to the chassis.

MG In reply:

Yes. That's the reason for the sharp nail or test probe point, to get to
metal (if it exists.) I certainly don't intend to patronize anyone, but
there are many readers of this list with varying levels of skill. I
attempted to present a simple, easy to understand testing technique, a
further refinement of Rick Staples post on 3/22/99.

Since the cone is held on with a fastener, it doubt the coating is so
complete an insulator you wouldn't get and indication of electrical
continuity. As a side note, my '77 had the original air bellows (bags) on it
when I got it; it had metal cones, still does today.

> Was there actually a recall of the plastic cones. If so
> shouldn't it still
> be in effect?

I don't think a 'recall' as we know them today were handled in the same
manner in the '70s. Undoubtedly, this issue was covered in a service
bulletin. Phil Stewart asked the same question in December, and someone who
has a collection of these bulletins would surely know. I do not.

'Recalls' as we know them today are registered letters and phone calls (at
least from Chrysler and VW). 'Service bulletins' and 'product alerts' from
the past are a different matter. I know personally of some *major* work that
was done by my local Chev/Pont dealer because I complained. I'm not sure
that work was covered by a recall, but we would all probably agree that it
should have been. Certainly, we all know there was a field upgrade effort of
some sort, and I guess that's the unanswered question: How did GM handle it
and when? Whether we get an absolute answer to this question is determined
by how far someone wants to research this issue or take it up with GM.

As to whether you want to use the plastic cones or replace them with metal
is a personal decision that can be made based on the information that has
been provided on this list. There seems to be first hand evidence that
plastic cones do in fact, disintegrate; metal ones do not. [Bob Morris,
3/22/99]

Each person reaches a conclusion of a satisfactory level of personal safety
and accepts the responsibility for potential property damage on their own.

Out. Mark Grady

 

[mark grady]

> I will try it but if the cones are coated with a plastic than
> they will more
> than likely not conduct electricity to the chassis.

MG In reply:

Yes. That's the reason for the sharp nail or test probe point, to get to
metal (if it exists.) I certainly don't intend to patronize anyone, but
there are many readers of this list with varying levels of skill. I
attempted to present a simple, easy to understand testing technique, a
further refinement of Rick Staples post on 3/22/99.

Since the cone is held on with a fastener, it doubt the coating is so
complete an insulator you wouldn't get and indication of electrical
continuity. As a side note, my '77 had the original air bellows (bags) on it
when I got it; it had metal cones, still does today.

> Was there actually a recall of the plastic cones. If so
> shouldn't it still
> be in effect?

I don't think a 'recall' as we know them today were handled in the same
manner in the '70s. Undoubtedly, this issue was covered in a service
bulletin. Phil Stewart asked the same question in December, and someone who
has a collection of these bulletins would surely know. I do not.

'Recalls' as we know them today are registered letters and phone calls (at
least from Chrysler and VW). 'Service bulletins' and 'product alerts' from
the past are a different matter. I know personally of some *major* work that
was done by my local Chev/Pont dealer because I complained. I'm not sure
that work was covered by a recall, but we would all probably agree that it
should have been. Certainly, we all know there was a field upgrade effort of
some sort, and I guess that's the unanswered question: How did GM handle it
and when? Whether we get an absolute answer to this question is determined
by how far someone wants to research this issue or take it up with GM.

As to whether you want to use the plastic cones or replace them with metal
is a personal decision that can be made based on the information that has
been provided on this list. There seems to be first hand evidence that
plastic cones do in fact, disintegrate; metal ones do not. [Bob Morris,
3/22/99]

Each person reaches a conclusion of a satisfactory level of personal safety
and accepts the responsibility for potential property damage on their own.

Out. Mark Grady