De-zincified P- bracket - replacement options?

[skyflyer]

Turns out that our P bracket isn't bonded and has suffered galvanic de-zincfication and the engineer says it should be replaced (or risk it breaking off if knocked etc)

Being an american boat, my first port of call was to US manufacturer and I am quoted approx £400, but there will be shipping and VAT to go on top of that.

Obviously we have the old one as a pattern so the questions are:-

• can I use the old one as a pattern for a foundry to cast a new one
• is there a specialist manufacturer who could do the job
• how crritical is the alignment and boring of the hole for the propshaft - I would have thought "very"!
• Would fabrication using stainless steel be an option?

This is what i think is called the 'plate' type not 'glassed in', so it has a curved horizontal plate with 4 holes in it through which it is bolted to the hull

 

[Tranona]

If it has dezincification it is not just because it was not bonded to an anode but because it was cast in rubbish material, probably just brass. So don't waste £400+ on more rubbish. You can use the existing one as a pattern. You need to find a foundry that will do it. Teignbridge and Clements are possibilities. Will likely be similar price to importing one but they will use a good material. Alternatively it could be fabricated from stainless. Although the alignment is critical there is a degree of adjustment when bolting up using spacers. With compatible fastenings there should be no need for an anode.

 

[oldharry]

I had a new one made up in stainless this summer for my 24 footer. Cost 250 beer tokens. The weder did a final check of the top plate angle before assembling it. Seems fine. I was advised having a new one cast was an option, but did not prsue it.

 

[vyv_cox]

When I replaced mine, full description at http://coxengineering.sharepoint.com/Pages/Pbracket.aspx I found it very easy to align the new bracket and cutless bearing with the shaft, in fact considerably easier than re-aligning the engine and gearbox. I would do as suggested, remove the old one and have a copy fabricated. Casting a replacement is likely to cost far more than fabricating one but the welder needs to be knowledgeable when making it in stainless steel.

 

[burgundyben]

When I replaced mine, full description at http://coxengineering.sharepoint.com/Pages/Pbracket.aspx I found it very easy to align the new bracket and cutless bearing with the shaft, in fact considerably easier than re-aligning the engine and gearbox. I would do as suggested, remove the old one and have a copy fabricated. Casting a replacement is likely to cost far more than fabricating one but the welder needs to be knowledgeable when making it in stainless steel.

I read the post and wondered what you'd say. I try to avoid putting stainless underwater. Hateful material. I would cast it in bronze.

 

[SHUG]

P-brackets are widely available. I got mine from Barcelona for fitting in Mallorca.
It had developed a crack and a local lad volunteered to weld (braze) it. When it was heated it oozed water like a sponge and was clearly dead. It was cut out with an excellent pneumatic hacksaw and then re-glassed into position with a shoe-box internal moulding. Good repair.