SanFran 12 Posted September 5, 2011 Share Posted September 5, 2011 Just been hauled out for the annual do up. Noticed the cup/scoop thingy on the hull for the engine water intake has gone for a swim in the last 12 months or so what I want to know is.... Has anyone found it while on a dive out there? Okay... real question is, what would the condition of the screw holes into the ply hull be like? (other than being saturated). And the suggested course of action.... (comments here please) a. borrow the missus hair drier for hard out for the weekend and hope she doesnt notice? b. once dry, fill with something, put in bigger screws? Link to post Share on other sites
Kestrahl 6 Posted September 5, 2011 Share Posted September 5, 2011 Dig out any loose material. Maybe drill the holes oversize, make sure the inside is dry, fill with epoxy and then re drill new holes in the epoxy when it is set to fit the old screws.. This way water can't go up the screws into the ply. Link to post Share on other sites
ab1974 1 Posted September 5, 2011 Share Posted September 5, 2011 Bit confused - do you mean the thru hull fitting that joins to the sea cock? Rot normally caused by fresh water rather than salt. Would try to dry (maybe heat gun or time rather the and misses hair dryer!) then drill out holes and fill with epoxy. Re drill and fit to sea cock. Though can't understand how the sea cock could fall out and not leave the hull flooded? Link to post Share on other sites
Kestrahl 6 Posted September 5, 2011 Share Posted September 5, 2011 They go over the skin fitting hole and are held in place by 3 screws Link to post Share on other sites
wheels 543 Posted September 5, 2011 Share Posted September 5, 2011 They usualy have a grill toward one end and scoop the water into the intake to create a little pressure and stop possible cavitation. They work very well at allowing a plastic bag to simply wash over and not get sucked in. It is well worth replacing it. The best way to fix the problem is to drill the holes just slightly larger and if you can, a drill/plug tool is good. Otherwise, a dowl plug and drill the hole just slightly tight of the plug size. Allow to dry the best you can, then evidure or Epoxy mixed with 10% thinners, to allow to soak well in and then drive the plug home. Then the rest of that thinned epoxy over it again, drill the new holes, paint the thinned epoxy in the holes. Then a small bead of Adhesive Sealant around the grill contact edge and screw the thing in place, but not tight. Keep a very little Bead of Sealant between the grill and hull. Then after it has cured, screw it home. That creats a compression seal and water will not get into the screw holes. Use Silicon Bronze screw. DO NOT use SST screws. In the timber, they do not breath and will not last long till they rust as if they were simple steel screws. Link to post Share on other sites
SanFran 12 Posted September 6, 2011 Author Share Posted September 6, 2011 They go over the skin fitting hole and are held in place by 3 screws Thats the one.... 4 screws holding the bronze fitting on to the glass over ply hull. Many thanks for all the responses... I knew thered be a right way to do it. Cheers Link to post Share on other sites
Guest Posted September 7, 2011 Share Posted September 7, 2011 DO NOT use SST screws. In the timber, they do not breath and will not last long till they rust as if they were simple steel screws.. FAROUT!! I never thought of that one! Of course you are dead right Wheels, remove the oxygen and wammo! (looking foward to some pix of your voyage!!) Link to post Share on other sites
wheels 543 Posted September 7, 2011 Share Posted September 7, 2011 Yep, when I cam across that one 7yrs ago, I had thoguht the guy that biult my boat was an idiot for using simple plain steel screws and nails. And this was above waterline in the ply topsides. Whenever water got into the ply, the SST screw or nail would turn to a sliver of pure rust. It was not untill I talked to a boat biulder that he said, oh the guy used SST and this is what happens. So now I use Copper or silicon bronze Only and SST inside the boat if I know it will be dry. SST outside will even rust under paint and glass. The more it is kept free of ocygen, the greater the possibility that is will corrode. It takes very little moisture to start and if you have used treated ply or timber, the metal(arsnic and copper) in the treating will also react with the SST. Link to post Share on other sites
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