Author Topic: Fastenings for galvanised floors  (Read 399 times)

Sniper

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Fastenings for galvanised floors
« on: November 18, 2017, 10:19:46 AM »
I'm in the process of removing and replacing the fastenings which go through the centre of the galvanised floors. Not surprisingly after 50 years the original galvanised bolts have wasted  away to a thread and as soon as I turned the nut on top the bolts snapped.

Anyway, my main issue is what to replace them with.  I plan to remove and regalvanise the strap floors as I can't afford bronze replacements. I'm leaning towads refastening with galvanised again - if they last another 50 years I probably won't be interested in replacing them again.  However I wonder if stainless would be a viable alternative?  The two forward keel bolts are stainless and are showing no signs of anaerobic corrosion.

Any thoughts welcome!
(By the way, in case there is any doubt Sniper is a wooden boat)

damarri

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Re: Fastenings for galvanised floors
« Reply #1 on: November 18, 2017, 01:32:48 PM »
My only thought would be that stainless and zinc or carbon steel are electrolytically "dissimilar metals" and as such don't mix,  particularly in a wet environment.  I think I would stick with galvanized fastenings.......  and as you say,  in 50 yrs time,  if they need replacing again it won't be your problem!

Paul

Lodesman

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Re: Fastenings for galvanised floors
« Reply #2 on: December 04, 2017, 01:42:43 PM »

  Hi Tim

  +1 for the dissimilar metals - stainless bolt didn't go well with my galvanised plate.  Another vote for galvanised fittings...

  James (Fred)

rikgaffer

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Re: Fastenings for galvanised floors
« Reply #3 on: February 01, 2018, 08:08:02 PM »
Another vote for galvanized bolts. If you use stainless the bolts will be fine but the galvanizing round the fixings will quickly disappear due to electrolytic action with the stainless. Just a note go to a reputable company ( The Galvanized Bolt & Nut Co. or South Essex Fasteners are excellent) and get hot dip spun galvanized bolts. There are many bolts on the market which claim to be galvanized but are merely zinc plated.

damarri

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Re: Fastenings for galvanised floors
« Reply #4 on: February 01, 2018, 08:49:32 PM »
Hi Rikgaffer and welcome to the Forum..........At the risk of exposing my ignorance, what is the difference between galvanizing and zinc plating?

steve

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gel coat repair and rust spots on fin keel
« Reply #5 on: March 22, 2018, 10:55:41 AM »
Hi there
Anyone know how best to fix these?
« Last Edit: March 27, 2018, 09:05:58 PM by damarri »

damarri

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Re: gel coat repair and rust spots on fin keel
« Reply #6 on: March 27, 2018, 08:28:03 PM »
Hi there
Anyone know how best to fix these?

Steve,  I think International's "Primocon" is the way to go.  Just scrape/sand the area down to clean metal, clean off and apply it with a brush.  Two coats with the first coat very slightly thinned.  Strictly speaking I think you are supposed to thin it with "No.1 Thinners" but I have found that white spirit works just as well and you clean the brush with white spirit.  Antifouling can go straight onto Primocon.

Paul
« Last Edit: March 27, 2018, 09:03:06 PM by damarri »