Prop zincs with inner band
 

Hi,

I believe it was in Nigel Calder that I read -

better propshaft zincs have an inner band that is bonded to the prop
shaft, eliminating loose connections to the shaft after the zinc has
been partially eaten.

Does anyone know of a good source for these higher quality prop-zincs?

Thanks,

Mike.

Hey Mike,

I don't recognize the quote or the product. Zincs intended for prop
shaft mounting tend to be pretty much alike in my experience. These
zincs can be almost completely sacrificed and yet be firmly attached to
the shaft. Of course, you would want to replace the zinc well before
that stage was reached.

Are you having a problem with the zinc working itself loose after it is
partially sacrificed? Or just pursuing greater reliability?

Chuck

beaufortnc wrote:
Hi,

I believe it was in Nigel Calder that I read -

better propshaft zincs have an inner band that is bonded to the prop
shaft, eliminating loose connections to the shaft after the zinc has
been partially eaten.

Does anyone know of a good source for these higher quality prop-zincs?

Thanks,

Mike.

Here is a trick I read about, but haven't tried for MaxProp zincs, but I do
recognize the symptom:

These zincs are a cone shaped piece of metal that screws to the face of the
prop with three screws in each of the corners. The problem is that there is
very little metal surrounding those screws, so after a bit of wastage, the
whole thing falls off. But if you paint around the screw holes with
fingernail polish, that will protect the metal that holds it together and it
will last much longer.

There is plenty of surface contact with the prop face assure a good
electrical continuity. The same is true for the ID of prop shaft zincs.

David

"beaufortnc" wrote in message
oups.com...
Hi,

I believe it was in Nigel Calder that I read -

better propshaft zincs have an inner band that is bonded to the prop
shaft, eliminating loose connections to the shaft after the zinc has
been partially eaten.

Does anyone know of a good source for these higher quality prop-zincs?

Thanks,

Mike.

With all zincs, including the MaxProp: Smack them with a hammer for
better contact, then torque down again. Ours all decay from the outside
mostly.

In article BvxOe.70252$DW1.68237@fed1read06,
"David&Joan" wrote:

Here is a trick I read about, but haven't tried for MaxProp zincs, but I do
recognize the symptom:

These zincs are a cone shaped piece of metal that screws to the face of the
prop with three screws in each of the corners. The problem is that there is
very little metal surrounding those screws, so after a bit of wastage, the
whole thing falls off. But if you paint around the screw holes with
fingernail polish, that will protect the metal that holds it together and it
will last much longer.

There is plenty of surface contact with the prop face assure a good
electrical continuity. The same is true for the ID of prop shaft zincs.

David

"beaufortnc" wrote in message
oups.com...
Hi,

I believe it was in Nigel Calder that I read -

better propshaft zincs have an inner band that is bonded to the prop
shaft, eliminating loose connections to the shaft after the zinc has
been partially eaten.

Does anyone know of a good source for these higher quality prop-zincs?

Thanks,

Mike.





--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

I've noticed that the zincs intended for attachment to prop shafts have
a slightly smaller radius of curvature than the stamped size. I wondered
about this and considered the smacking technique to provide greater
surface area.

Usually, high electrical resistance is not a big problem with this type
of zinc. What is more important is that the mechanical "bite" of the
zinc on the shaft remain tight. If the zinc ID is slightly undersize,
the zinc will contact the shaft at four places. For a given torque on
the attaching bolts, there will be much more pressure (psi) with an
undersize zinc than if the zinc ID were exactly the same as the shaft
OD, where the pressure is spread more uniformly around the circumference
of the shaft. Think about serrations on the jaws of a pair of pliers as
an analog. So I wonder which is really better, assuming both provide
satisfactory electrical contact.

Chuck


Jere Lull wrote:
With all zincs, including the MaxProp: Smack them with a hammer for
better contact, then torque down again. Ours all decay from the outside
mostly.