P-bracket leak

wragges

Well-Known Member
Joined
7 Nov 2005
Messages
145
Location
Nottingham, UK
www.minstercomputers.com
Hi,

Have a slow and minimal ingress from the P-bracket on a Westerly Seahawk. Only about 1/4 litre per day, but it builds up and then overflows on to the cabin carpet when healed. then I get GBH to the ear from the co-skipper.

The bracket appears to be solid and bonded okay from the outside.

Any suggestions on how to cure it without having to remove the entire bracket (re-glassing etc).

Is there a kind of Gel overcoat that I could apply to the outside?
 
Is the P bracket bolted through the hull? If so I would guess the water must be getting through the bolt holes. If so I would take the inside nuts/washers etc off and squeeze sikaflex down the bolt hoes, leave some to seal under the washer, and then put the nut back on.
 
I take it you mean that water is coming in where the P bracket is bolted to the hull, rather than via the shaft tube. In that case the cause might be corroded bolts, or possibly that a misaligned shaft is straining the P bracket mountings. Can you get at the nuts on the inside? If so I think you should examine the bolts. In any event a leak like that will only get worse, so I think you have to grasp the nettle and find the exact cause of the leak rather than just trying to seal it from the outside.
If the boat is coming out of the water this winter you should check the shaft alignment because engine mounts tend to compress over time and can put strain on the shaft and P bracket, particularly if you have a rigid shaft coupling. If it does not turn freely when in neutral with any adjustable packing gland slackened off a bit, the shaft alignment may be suspect.
 
I had this problem on a First 35 where they glass the PB in during construction. Bit of a hack job to fix, but with a little destruction and sophisticated weaponry we got it beat! There, the PB "strut" comes up straight into the hull and terminates above the deadwood. With the boat on the hard for a tide, I drilled in with a long-series 5mm drill all round the PB, and at various angles, till the drill touched the stainless steel. This made a sort of "root-system" from the PB to fill with epoxy. I put a number of syringes of slow-set into the holes to supply the goop into my "sponge", and with a mate outside with the Hoover, we injected epoxy into the holes, and sucked it through between the s/steel and the hull until the supply-holes were full, and the epoxy was flowing "freely" out down the PB. We stopped the egress of epoxy with some Simson, and now, some 30000 nM later, the wretched PB STILL won't leak a drop! It all started with a line round the prop, which bent the shaft just a fraction, but with a flash of brilliance it was cured in about 10 hours. 8 hours for a crankshaft-shop to precision-straighten the shaft, and 2 hours for me and a mate to goop the PB tight again! I don't think we weakened the deadwood, as we only punched in about a dozen 5mm holes, which were epoxy-filled and with the epoxy, formed a network which bonded the glass to the s/steel very effectively.
Hope this helps a little!
 
Just fixed the P bracket on a Westerly GK24. My leak was about half a pint a week. It had also de-zincified so I had to hack the glassing around the old bracket away inside the hull, remove it and re-glass the new one .
Bracket £220. 4 day lift store ashore & relaunch £160. Epoxy and glass tape and other materials £100. Two days of leave ... priceless ..
Best method for removing laminate - Tesco chinese £1.00 chisel filed to a blade whenever it blunted, and used with a wooden mallet.
 
It surprised me to learn that P-brackets are not custom made for each boat with an appropriate flange. Instead, many are made to the same overlength design but cut to length as required. Like this:

IMG_2210.jpg


This means that right-angled brackets need to be bolted to the P-bracket to attach it to the boat. On mine the attachment bolting was done very poorly, as can be seen in the photo above, and the cause of leakage was very slight movement of the P-bracket itself in the hull. The polyester or epoxy resin plus glass don't contribute a lot to the overall rigidity. Here's a picture of my hull after removal, to give you an idea of what is there:

IMG_2215.jpg


You might be able to bodge some sealant into the gap between hull and P-bracket, after making a suitable groove, but quite honestly you might as well do the job properly. Chop out the old GRP, as said a cheap chisel is a good method. Then fit up the new bracket to the hull and carefully mark the position of the brackets. Through-bolt the brackets and P-bracket using generously-sized bolts and do them up tight. Then, after making sure everything is aligned as well as possible, fix the assembly into the hull using epoxy resin plus filler and bolting the brackets. Ensure that plenty of filler goes between the P-bracket and hull; I used masking tape on the outside to prevent it from running out. When this has gone off lay up epoxy and glass to cover everything and make it leak tight.
You can flow coat internally to make it look better.

You will almost certainly need to re-align the engine to shaft when back in the water.

My P-bracket came from Lake Engineering in Poole.
 
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