Wobbly P bracket

SteveB_Sigma33

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First of all a big Thanks to the people that replied to my request for advice on changing a cutlass bearing. Much appreciated.

However, it seems the problem lies in the fact my P bracket can flex 1mm left or right!

Has anyone else had this problem? If so what did you do to rectify the problem.

I'm getting a quote from the yard, but don't want to be ripped off!

I don't know if its feasible to grind a slot into the hull gel coat to enable repacking the bracket with resin and chopped matt. Any gurus with advice!?!?!



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I have heard it's possible to grind out some of the surrounding GRP and repack it, though you would need to be careful about maintaining temperature while it cures.

When we had our P bracket rebuilt it cost about £600, and that was 7 years ago. Fortunately this was spotted by the surveyor before the sale went through so it was not our problem. In fact I think the broker paid! The movement was more than 1 mm.

It involves grinding out the GRP box inside the hull (very messy) and rebuilding the whole installation, quite a careful process of jigging to maintain the shaft alignment. I would get a couple of quotes.

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We had this problem several years ago. The movement in the P bracket was more than 1mm, though not too much more from memory.
The solution was not too complex. First, several small holes (about 3mm) were drilled from the inboard side through the GRP surrounding the P bracket mounting as far as the metal of the P bracket. (The P bracket was held in place by a big lump of GRP around its inboard end.) The holes were arranged all over the lump of GRP. Then isopropanol was carefully injected into these holes and watched dripping out of lower holes and out of the gap beteen hull and P bracket. The isopropanol was used to dry out the GRP and to clean the surfaces (hopefully). The injecting was done with a syringe. The hole size fited the syringe fairly close.
Air was next blown throught to help evaporate the isopropanol (using a syringe again).
Finally, epoxy was injected (3rd time for the syringe) into the holes, aiming to fill all the spaces up and fix the P bracket. All the inboard holes were resealed by this. Disappointingly, the epoxy didn't drip out of the P bracket/hull joint except at a couple of places but given its viscosity I am not very surprised. It may be possible to get low viscosity epoxy or it can be heated to make it more runny but that also shortens the curing time.
I tried to fill the hull/bracket joint with epoxy all round on the outside to compensate for it not penetrating well from inside.
Finally, the joint was covered with sealant (Sikaflex probably). The sealant was found to come loose after a few seasons and was replaced. But the bracket stayed firm from 1990 to when I sold the boat in 2002.
I was not confident that it would surviuve so well.
I hope that helps.

Derek

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Steve

I have posted a reply on your original plea, so I wont repeat myself. I dont know how we contact each other, but I can help with a tool for removing and refitting the cutlass bearing, in fact if anyone is about to do the same job , form a Q, I dont use the tool anymore (the puller that is) as I have a saildrive!

We suffered the wobbly P bracket problem, several years ago, after getting a rope around the prop; you are getting lots of advise on that one, all sound very good.

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G'day Steve,

You are correct to use epoxy resin, however, don't use chopped strand mat, it will hold way too much resin and weaken the whole job.

With epoxy resin you are looking for a ratio of one to one, resin and mat, with wax resins the ratio is more like 3 resin to 1 mat.

So only use fabrics that are designed for use with epoxy.

I hope this helps, worth checking when you get a quote done. as is a warranty to cover both materials and workmanship.

I hope this helps...



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