Rusty Keel

[Sailfree]

How do you treat any rust spots on your keel.

Will hammerite paint over the rust work as claimed?

 

[ghostlymoron]

I've not found Hammerite much use underwater on a rusty keel. I also tried Hammerite primer no. 1 which wasn't any better. The ultimate solution is
1. grit blast to SA2.5
2. immediately prime with zinc rich primer (international primocon) 2 coats
3. Antifoul
You should have no problems for 5 years (obviously repeat anti fouling annually unless you are Dylan Winter)

But if you are on a budget use a wire brush on an angle grinder as surface preparation and accept that you will have to treat patches most years.

 

[duncan99210]

If the rust spots are enough of a problem to be removed, then brace yourself for some hard work. You need to remove all the old paint and get back to bright bare metal. I used sanding discs on an angle grinder, along with flap wheels for a small angle grinder for the fiddly bits. Then treat with either rust converter or acid (which needs removing with baking powder in solution), then 2 or 3 coats of primer, followed by a couple of coats of epoxy followed by anti foul primer followed by as many coats of anti foul as you see fit.

Filthy dirty work, back breaking 'cos your stooped under the keel all the time and you need good weather through out. How do I know? Just finished putting the first coat of epoxy on Rampage's kell after doing the above.

Why did I do it? Well, last year I tried the wire brush the rust spots, paint them with some patent gloop that claims to prevent rust before covering with anti foul. Result? Even more rust spots this year, so I gave in and got on with the job....... Now I just have to hope that the weather stays good for a couple more days to finish off the job.

 

[Fantasie 19]

Have a read here... there are views that Hammerite can be quite effective...

http://www.ybw.com/forums/showthread.php?t=306558

...I've used it on mine for the last few years and have been happy with the results....

 

[Seajet]

I've never had any luck at all with Hammerite, what I have found brilliant is Dulux Metalshield, it's OK for steel or alloy and way superior to anything else I've tried - and I reckon I've tried everything, inc Primocon, Blakes Steel Treatment, you name it...

This Metalshield really stays on, a different league to the rest; it's one - pot, but requires the Metalshield Primer, also 1 pot; roughly £20.00 each from Brewers.

No connection other than chuffed to have found it.

 

[wooslehunter]

1. Clean off the rust with whatever weapon suits.
2. Vactan rust converter.
3. Several coats of primer like primocon.
4. Antifoul.
5. Launch.
6. Have fun.
7. Go back to 1 above & repeat for ever.

Alternatively, get the keels blasted & professionally primed & epoxied. To got mine blasted but being a cheapscate, I expoxied myself.

Now I'm following the numbers above. Epoxy is comming away in places.

 

[Seajet]

got mine blasted but being a cheapscate, I expoxied myself.

No wonder it's coming off in places !

 

[theoldplucker]

Epoxy, primocon is fine if you are laid up in a dry yard. Winter berth on a beach, I wire brush, sand bare spots and paint with red oxide before antifoul.

 

[VicS]

Save the Hammerite for the garden gate.
By all accounts the latest formulation isn't much good for that either

 

[oldsaltoz]

All the answer here,

http://www.google.com.au/search?q=Y...s=org.mozilla:en-US:official&client=firefox-a

Good luck.

 

[colhel]

woops

 

[colhel]

1. Clean off the rust with whatever weapon suits.
2. Vactan rust converter.
3. Several coats of primer like primocon.
4. Antifoul.
5. Launch.
6. Have fun.
7. Go back to 1 above & repeat for ever.

Did mine this way last year, still good this year

 

[lufc71]

Apparently 'Rustoleum' works pretty good:-

 

[onesea]

Did mine this way last year, still good this year

I found I managed about 3 years... Like this but maybe a coat or 2 more primer.

The way I look at it is:
1) stop the rust (rust converter)
2) then seal (primer)
3) then protect it Antifouling

 

[ghostlymoron]

Apparently 'Rustoleum' works pretty good:-

It doesn't seem to have protected the tin!

 

[BAtoo]

Best option is professional grit blast & immediate coating with epoxy or VCTar etc then plenty of Primocon ( AF )

Anything else is a compromise.......

Hammerite is better than nothing, and better than some other things; but it will fail.

Did son's keel with it after grinding off and it survived about 18months continued immersion. When blasted off at lift out I see its 50% gone.

Did my Squib keel, which always winters ashore, grind & Hammerite and its going in places on its 3rd season - so again about 18 months immersion.

If you are just spot treating I would scrape and Primocon etc & get the job done properly next winter.

 

[KellysEye]

>1. grit blast to SA2.5
2. immediately prime with zinc rich primer (international primocon) 2 coats
3. Antifoul
You should have no problems for 5 years (obviously repeat anti fouling annually unless you are Dylan Winter)

I agree, thar's what we do and it works. I haven't tried Metalshield but from Seajet's comment it might be worth trying first as it's less complicated and cheaper.

 

[lw395]

I had a totally rust free keel on my last yacht.
It was made of lead.

Previous one mostly did ok grinding back to shiny metal with a sanding disc, jenolite, then a few coats of west epoxy or SP. Warming the epoxy as it goes on with a hot air gun seems to help.
Some people recommend applying the first coat of epoxy using coarse wet and dry, in a sort of wet sanding action to get a good bond with the metal.

 

[Blueboatman]

Theoretically hot cast iron will be infinitesimally more porous ( therefore receptive to thinned epoxy) than when cold. I suspect the truth is that a keel that has been baking in sunshine all morning will be devoid of dampness in its pores....
I have never managed to stop a car rusting nor a cast iron keel indefinitely, short of grit blasting to shiny metal

 

[AntarcticPilot]

Several people have suggested sand-blasting a cast iron keel, and similar threads in the past have also suggested that this is the best way to remove existing rust and prepare a clean surface for primer and epoxy coating.

Of course, a commercial sand-blasting company is probably the simplest solution for many people. But has anyone any experience of using a sand-blaster accessory for a pressure washer (e.g. THIS)? Would it do the job?

I guess such an accessory might well be usable with other media than sand, which would make it a useful and versatile addition to the boat maintenance toolkit. Perhaps (with the right medium) it could be used to remove anti-fouling?

PS: I just checked and it seems that both Magnesium Sulphate and Bicarbonate of Soda are suitable for this kind of pressure-washer sand-blasting, and the former is specifically advertised as being suitable for removal of paint from the bottom of boats!