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#1
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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. |
#2
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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. |
#3
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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. |
#4
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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/ |
#5
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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. |
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