Galvanising

[calloo]

Is it a sensible option to re-galvanise old chain plates and deck fittings which stain my boat with rust? I suspect it would be more sensible to replace these fittings with stainless steel. I have never found a place which re-galvanises old fittings, but would appreciate any advice.

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[chippie]

I had an anchor regalvanised which was a lot cheaper than a new anchor. I found the galvanisers through the yellow pages. There was a base charge for sand blasting and a charge for the weight of the zinc used. If your fittings are in otherwise good condition I think it would be well worth it as you avoid some of the pitfalls of ss.

Although I am in NZ I'm sure that the situation re galvanisers is much the same .

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[Peterduck]

The biggest problem with just getting the chainplates done is that galvanisers have a hefty minimum charge; the last time that I had some work done it was A$80. You can get quite a lot of work done without the charge going up, so it is best to seek someone else in your area who also needs some parts galvanised and pool the parts and share the cost. Weigh the parts to get a correct sense of the proportioning of the costs. Whether to replace the chainplates with stainless steel depends on the depth of your pockets and the length of your arms. You would have to be certain that you were getting 316 grade [non-magnetic] and not 304 grade [slightly magnetic]. The latter will still rust, which defeats the purpose of using it.
Peter.

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[Talbot]

Most galvanising laces in UK charge a flat base rate plus cost of the actual galvanising. This can make the cost far outway the value, but there is a way round it. Go to a trailer manufacturer (lots in Yellow pages. They normally send of lots of stuff to the galvaniser, and most are quite happy to add yours into their load just for the cost of the galvanising.

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[ccscott49]

Most galvanisers are willing to add your stuff to a batch going in, as long as you are willing to wait a little longer for them to be done, try the back door method, for a couple of pints!!

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[calloo]

Thanks to you all for your helpful comments.

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[rjp]

Definitely worthwhile. Not all galvanisers have a high minimum charge. I had a load of stuff done in Liverpool for around £100. I think the minimum charge was £30 but I took the opportunity to get the anchor and several other weighty items done.

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[Davy_S]

I took my anchor and several other bits to a local gate maker, they sent them off to the galvanisers in Liverpool along with their stuff. Cost me just over 50p per pound to have done. No cleaning off involved,I think they acid dip the parts to clean them.

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[Gordonmc]

I don't know where you are in Scotland, but I used a galvaniser in Glasgow who did a bag o' bits for about £30 two years ago. Six chainplates, gammon iron and bits of windlass.
It may have been cheaper because I left the stuff with them and was relaxed about how long it took. As a precaution I took photos of the bits before losing sight of them.
It will be a bit more expensive if they have to sand/grit blast any paint.
Clydesdale Galvanisers. 0141 334 9678. www.clydegalv.co.uk
Just off the Expressway.
If you decide to replace the kit, bronze would be preferable to stainless.

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[Gordonmc]

Clydesdale Galvanisers in Yorkhill, just off the Expressway in Glasgow did my chainplates, gammon iron and some other odds and sods for about £30.
Blasting will ben needed if there is paint adhering, but the price can be kept to a minimum if you are relaxed about when you get stuff back. I took photos as a precaution, but everything was in order a week later.

If you do decide to replace I suggest bronze would be prefereable to SS, especially if your rigging is galvanised wire rope.

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[Mirelle]

It will be much cheaper and better to have them regalvanised. No risk of crevice corrosion which you might get with stainless.

I may the the only person who suggests bolting them back on with bronze bolts, though. There is a sound theoretical basis for this, in the case of chainplates and deck fittings, which I can explain if anyone's interested.

Wrought iron floors can be tricky to regalvanise as they pick up chloride ions; this is the trouble with the Great Britain and the Cutty Sark, incidentally.



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[ccscott49]

Go on, Go on, Go on, Explain.

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[Mirelle]

Charles, you know the answer!

But, OK, it's because where the volume of the less noble metal substantially exceeds the volume of the more noble metal, as in the case of a galvanised steel fabrication or galvanised iron casting secured by bronze fastenings, the wastage rate is very low.

The fasteners are highly stressed, vis a vis the fitting, and it is important that they are preserved. If you use galvanised screws to secure a galvanised casting the screws will waste a little faster than the casting, because they have a proportionally bigger surface area and they are stressed, and this you do not want.

What one should not do is to fasten a bronze casting with steel screws - the fasteners would be gone in a matter of days!

Look round your decks and I bet you will find at least one, maybe twenty, galvanised fittings secured with bronze screws and perfectly happy with it!

NB this applies to deck fittings; not under the waterline.

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[Plum]

stainless steel bolts with galvanised steel

In practice I have found nothing wrong with using stainless steel fasteners on galvanised fittings above the waterline. On two boats of mine this setup has lasted 15 years and by the condition of the galvanising will easily stretch to 18, maybe more, before I need to re-galvanise. The stainless bolts are showing no signs of deterioration, even on the hidden parts.

Of course, below the waterline is a different matter entirely.

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[Mirelle]

Re: stainless steel bolts with galvanised steel

Exactly!

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[ccscott49]

Just wondered if you knew the answer!! tee hee

Have used bronze screw bolts for lots of fittings! Including SS.

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