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- 23/11/2008 at 7:56 pm #3820AnonymousInactive
Hello, does anybody know what these fixings are on the keel bands of my GRP Mk1? And, most importantly, how to remove them completely so that I can replace them with screws?
They look like some kind of pop rivet – you can see them close to two of the ends of the bands in this picture. I guess that I can drill the heads off to get the bands off, but then how do I get the rest of the fixings out of the keel without damaging it?
I would like to fit a centreboard slot gasket over the winter, which will involve removing and then reattaching the keel bands around the centreboard slot. I’ve read the excellent article by Mike McNemara (see http://www.wayfarer-international.org/WIT/maint.repair.ref/CB.rudder/Slot.Gaskets/MikeOnGaskets1.PDF) but instead of seeing simple screws to undo I saw these things.
Does anybody know how to remove them completely so that I can relace them with screws when I fit the slot gasket?
W301623/11/2008 at 11:51 pm #7466SwiebertjeParticipant
They probably are Philips screws. Perhaps the they are worn down to the point the screw driver won’t “bite” anymore. In that case you could drill the heads off with a drill that has about the same diameter as the heads. But be careful to leave as much of the screws stems as possible. (you don’t need to drill all of the head off). After all heads are gone the strip should come off with some persuasion. Then with pliers, try to screw the remaining parts of the screws out. If normal pliers slip try grip lock pliers.
I cannot imagine someone would be so stupid to use pop rivets for this purpose but if someone did the procedure would be the similar to the one described above. The only difference is that you would most probably not be able to get the rivet remains from keel. Instead hammer the remains of the rivets in to the wood of the keel using some sort of round driver (the blunt end of a suitable diameter drill or so). Make sure the rivet remains are driven deep enough in to the wood of the keel to make room for a screw again. Then epoxy the holes and drill new holes (for screws this time) in the epoxy after it has set.
Your strips look like brass to me which was the standard on older boats, and there is nothing wrong with that! (New boats use aluminum strips). Brush the strip off with a steel brush and re-attach with new brass screws. There is no need to polish it, it will be black again minutes after it is exposed to salt water. Maybe you could use SS-screws too but my guess is they would not agree with the brass strips. Perhaps someone else could comment?
Use some sealant on the screw holes to prevent water ingress and if there is no “bite” consider fixing the hole first by injecting some epoxy resin in it.24/11/2008 at 11:43 pm #7468Dave BarkerKeymaster
Maybe you could use SS-screws too but my guess is they would not agree with the brass strips.
There is a useful article on this topic at:-
A table headed “Fasteners for Fittings” just over half-way down the page confirms that SS fasteners should be avoided for brass fittings. The reason is clear from the “Galvanic Chart” higher up the page, and the accompanying text. Use brass or bronze fixings for brass, is the message.25/11/2008 at 1:23 pm #7469AnonymousInactive
Thank you both Swiebertje and Dave.
The fixings don’t look like Phillips screws to me; the holes in the heads look quite round, but then they don’t look like pop rivets either. The boat has a Small Craft label on it – does any body know what fittings that they used back in the early seventies?
I shall take you’re advice Swiebertje and drill off the heads then attempt to remove the shaft of the fittings with a pair of grip lock pliers.
My main concern is for the fittings on the bow and stern keel bands. I’m not planning to remove the keel bands entirely and so getting to the shafts of the fittings under the existing keel bands may prove difficult…
I hadn’t considered hammering the shafts of the fittings into the keel. It’s good to have an alternative if the mole grips don’t work 😉 .
Thank you very much for your link to the article on “Metals in a Marine Environment” Dave. It’s an excellent and amusing article and useful for anybody considering any metal fittings for their boat. I’ve always considered it wise to use the same types of metals together when bonding things on the boat . However this article makes it very clear why…
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