Galvafroid or alternative?

[DoubleEnder]

I have galvanised mild steel mast fittings for the spreaders. These are held in by the tension in the cap shrouds, plus habit, inertia and friction. Following a lucky escape last year I am going to fit pins, to hold the spreader roots in their sockets. This means drilling through the sockets, thus exposing ungalvanised metal.

What‘s the best way to protect this bare metal? Galvafroid? Epoxy coating? Something else? Any good ideas?

thank you

 

[anoccasionalyachtsman]

Have a look at Zinga from MG Duff (the gurus in anodic protection). Surfaces should be painted very soon after blasting, which might be a problem for you. It's been impressive on a couple of cars on which I used it extensively.

 

[jwilson]

This winter I used Rustoleum 1085 to repaint large square washers and keel stud nuts, after serious work removing surface rust, wire brush, then Fertan, then more wire brushing and oxalic acid. To date looks good. It's meant to be 90% zinc in an epoxty base. Rust Oleum 1085 Cold Galvanising Zinc Metal Paint | Specialist Paints

 

[JumbleDuck]

Have a look at Zinga from MG Duff (the gurus in anodic protection). Surfaces should be painted very soon after blasting, which might be a problem for you. It's been impressive on a couple of cars on which I used it extensively.

I have Zinga on the keel (plate and bulb) of my Hunter 490. It seems to have worked well where undisturbed, but it's brittle and comes off very easy where, for example, rollers press on the keel. In the OP's position I'd slather grease on.

 

[anoccasionalyachtsman]

I have Zinga on the keel (plate and bulb) of my Hunter 490. It seems to have worked well where undisturbed, but it's brittle and comes off very easy where, for example, rollers press on the keel. In the OP's position I'd slather grease on.

Interesting - did you have the keel blasted and painted over within the time and humidity specs? One car has had it all covered with their Tarfree stuff to minimise stone chips, but the 'project' has it unprotected, and despite unavoidable scrapes through it's definitely not flakey, and more impressively doesn't rust when bare metal is exposed.

 

[Rappey]

Chose whatever metal antirust solution jumps out at you.. Whatever you put on, the pins are going to rub through it and lead to rusting ? You do have an advantage that the steel will be totally clean when drilled through
Epoxy coating is the usual clean steel protection.
Maybe treat it and then seal it once in place with butyl or some other non setting sealant..

I paint a large ship every so many years... Have tried so many anti rust treatments (single pack) and all are only temporary as the rust keeps comming back. Red lead is the leading solution in my opinion but virtually impossible to get hold of.. Original hammerite wins hands down over all the others but whatever the magical ingrediant was is no longer present.
Have painted test patches of the ship with rustoleum, fertan, hammerite, por15 etc then painted over.. Monitored over a few years to see what does and does not work, hence what i have concluded.
The ultimate solution would be to regalvanise it but appreciate that may not be a cost effective or easy to do option.

 

[JumbleDuck]

Interesting - did you have the keel blasted and painted over within the time and humidity specs?

The blasting and coating was done by a local specialist, so I hope so. It has lasted fine on the bulb and the sides of the keel plate; it's just on teh leading and trailing edges, which run over rollers, that it has spalled off. Easy enough to touch up.

 

[Old Bumbulum]

Tefgel?

 

[anoccasionalyachtsman]

The blasting and coating was done by a local specialist, so I hope so. It has lasted fine on the bulb and the sides of the keel plate; it's just on teh leading and trailing edges, which run over rollers, that it has spalled off. Easy enough to touch up.

The 'retouchabilty' is interesting too. Duff had pics on their website showing that a fresh coat mixes pretty thoroughly with older layers. The claim that bare metal within 10mm of the Zinga surface won't corrode holds true for me with damp and rainwater - how was it with salt about? Not so good I'd imagine?

 

[JumbleDuck]

The 'retouchabilty' is interesting too. Duff had pics on their website showing that a fresh coat mixes pretty thoroughly with older layers. The claim that bare metal within 10mm of the Zinga surface won't corrode holds true for me with damp and rainwater - how was it with salt about? Not so good I'd imagine?

Dunno - the Hunter has only been used in fresh water since I had the keel done.

 

[DoubleEnder]

hmm. It is really a tiny area I have to protect. Maybe on reflection I'll fill and cover it with grease ( I usually grease the wooden spreader roots anyway) and wrap it all up with self amalgamating....