temporary repair on roof for rust area

[umpire111]

in the throes of buying a boat an assume owner shi p in net few days. For some reason \ Maxview Gazelle aerial is mounted on a block of wood about 3inches all round. This seems to be stuck on with mastic and rust is all around this and its badly blistered. Intend to have the boat painted next season but would like to scrape these bad rust spots off and temporary repair for over wintering. Was intending to sand down and apply Hammerite just for the winter- does that seems ok or can I just apply a primer?

[Jamboat]

Remove loose rust & give it a coat or two of vactan, should see you through the winter.

[Phil Ambrose]

Primer is not waterproof, needs paint of some sort on top.

Phil

[b0atman]

Hammerite smooth direct to rust is I believe waterproof

[Grace and Favour]

I'd wire brush the rubbish off, and then use a coat or two of Vactan, with just one or two coats of a topcoat paint. (primer and undercoat are too absorbent)

[kevinl]

I'd scrape or wire brush it back then give it a coat of rust convertor (link below) after 3 hours you can paint over it with Vactan or red oxide primer then personally I'd put a topcoat of something/anything on seal it all up for the winter.

K

https://www.londonpowertools.co.uk/decorating--wood-care-y/paints--spray-paints-y10/hammerite-one-coat-kurust-blister-90ml~zhmmock90?gclid=CKz8sJymvsACFSKWtAodCF8AoA#.VAN_ymdwbZ4

[davey b]

I'm not a fan of Ku Rust or any of the 'new' Finnigans products (or most of the ICI/ Akzo Nobel range including Dulux) because they no longer have the critical ingredients that gave them their reputation.

 

Instead of Kurust, i'd recommend Fertan or similar acidic based products or just straight on with the Vactan (which has added stuff over the active acid ingredient)

 

Or just wire brush & slap some paint on it until you have the full job done - that'll do for now

[Arthur Brown]

For an "over winter bodge" just scrape out most of the rust and cover liberally with Hammerite. For a better job clean back to metal, apply filler, primer, undercoat and then topcoat in your choice of contrast or matching colour.

 

Primer and undercoat have their purposes in a paint system but only properly applied top coat is waterproof.