Preparing to paint a steel boat

[Rustic Charm]

Hi all,

I'm preparing to give my 36 foot steel ketch a paint job, top and bottom. Not the deck.

It's a chimed and flared boat amounting to three chimes on each side. It's got lots of indents on both sides where it's been damaged and I've just patched it up at the time.

I can't sand blast it as there is no where it can be done locally.

I want to fill in the damaged areas with proper faring filler and bring the surface back to be flat. Paint will no doubt be done by paint brush and roller.

Looking at Norglass paints for the top sides and seriously considering Copper-coat for the bottom. I'm also considering using a two pac for the top sides too.

The question: because I'm not looking at sand blasting, and it's a fared boat, can I just patch the dents and use a two pac primer, fair those areas in preparation for the top coats? Where the fairing has gone can I just grind/ sand those areas down and try to limit the damage to those areas the fairing has gone?

And how many coats of primer do I need under the top coat?

[GordMay]

Have you considered soda blasting?

[Rustic Charm]

Originally Posted by GordMay

Have you considered soda blasting?

I can't 'blast' of any persuasion where I am due to local environmental restrictions.

[Snowpetrel]

You can blast down in Kettering, it's not soda they use, maybe glass bead, but it works well. Maybe also Devonport, or dunally. If there is no rust, you don't need to blast. If there's rust, blasting is the best way to get a decent key.



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[Rustic Charm]

Originally Posted by Snowpetrel

You can blast down in Kettering, it's not soda they use, maybe glass bead, but it works well. Maybe also Devonport, or dunally. If there is no rust, you don't need to blast. If there's rust, blasting is the best way to get a decent key.



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If I take it away, then I can't do it. I can pay to have it done in Devonport but at much more cost.

Shouldn't be any rust. It remains sealed.

[Uncle G]

I once saw a new steel boat which had been coated with a copper rich epoxy coating below the waterline. It was hauled out about a month after launching for some reason or other. I noticed that it had a very small 'ding' in the paint underwater (about 5mm diameter) - from hitting something - which had gone through the epoxy coating back to bare steel.

The steel in the 'ding' was shiny bright and about half its thickness had vanished due to electrolysis in the month that it had been afloat.

All that copper surface acting on the tiny amount of bare steel.

Copper below the waterline may work well if the epoxy system stays intact, but can you guarantee that it will do so?

[Truemettle]

I used to own a 43 foot steel boat and here is what I did. Acid wash the entire hull and then I cleaned it with DevPrep 88 applied 4 coats of Bar rust 235 and then 4 coats of a 2 part poly DevThane 238 as a barrier coat. I then coated it with micron CSC. I did the entire boat in DevThane and never had a rust problem. I would always repair any spider cracking or winch handle damage.

[hpeer]

Just having had a bad experience sand blasting and repainting I have no advice.

I have been frustrated with getting contradictory recommendations from experts and factory reps.

Good luck getting some consensus.

[Steadman Uhlich]

Originally Posted by hpeer

Just having had a bad experience sand blasting and repainting I have no advice.

I have been frustrated with getting contradictory recommendations from experts and factory reps.

Good luck getting some consensus.

Have you written about the bad experience anywhere (on the forum, in a blog, etc.)?

I am always looking to learn about steel boat issues and maintenance and stuff.

Anything about the bad experience you can share with us/me?

Thanks.

[jreiter190]

True mettle had given you the good way to get good results. I used to be a body and fender man for Broward Yachts in the'70's when we were building 87 footers.Not steel, but aluminum. Fairing is fairing. I also faired 46' gaff -rigged topsail wood schooners and a 55' steel muscle boat in Port Townsend. Don't go too thick on the fairing compound. Do it in layers or a bump might cause the whole thing to fall out. Follow true mettle's advice and you'll have a beautiful and lasting result. Good luck.

[Rustic Charm]

Originally Posted by Truemettle

I used to own a 43 foot steel boat and here is what I did. Acid wash the entire hull and then I cleaned it with DevPrep 88 applied 4 coats of Bar rust 235 and then 4 coats of a 2 part poly DevThane 238 as a barrier coat. I then coated it with micron CSC. I did the entire boat in DevThane and never had a rust problem. I would always repair any spider cracking or winch handle damage.

Thanks Truemettle,

I have purchased a 16 litre drum of what's called I think 'peel off', which is a paint remover. Once you paint it it on, then you cover it with a brown paper, tape it up and leave it from 24 to 48 hours and then peel it off using a scraper. The paint sticks to the paper.

I've then been given similar advice to yours about covering in the entire outside with a 2 part poly. I'll research what you have suggested.

[Rustic Charm]

Originally Posted by Truemettle

I used to own a 43 foot steel boat and here is what I did. Acid wash the entire hull and then I cleaned it with DevPrep 88 applied 4 coats of Bar rust 235 and then 4 coats of a 2 part poly DevThane 238 as a barrier coat. I then coated it with micron CSC. I did the entire boat in DevThane and never had a rust problem. I would always repair any spider cracking or winch handle damage.

It seems that Devprep 88 is not available in Australia. It seems it's a North American product only

And the same with Bar rust 235 ?


And Micron csc is an antifoul? Why would you put an antifoul on the topsides?

[Snowpetrel]

Originally Posted by Rustic Charm

Shouldn't be any rust. It remains sealed.

Hi RC, should be easy then, just sand out the dings, refair with epoxy bog, prime and topcoat. I'd use 2pack polyurethane and an epoxy primer.

I've used jotun and wattle products in the past with good results. The wattle rep in Tassie is very knowledgeable and helpfull (or at least he was a few years ago) so that's a good reason to use wattle paints. He was happy to come and look at boats personally, and advise.

Underwater is always an interesting juggle. If the paint isn't falling off in big chucks I'd just cross my fingers and repaint with good quality compatable antifouling. I'd be reluctant to put coppercoat over an old substrate, and it's a huge job to strip all the old antifouling back without a sandblaster. done it the hard way now on three boats.



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[Russ]

Have owned steel for 15 years. NOT blasting a BIG mistake on an old boat. Skip the fairing, spend the money on a good blast and use AMERON paint. Joint the Metal Boat Society they have loads of info. I use AMERON Primer and then AMERON on deck but Interlux for topsides ( a bit more shine then athe AMERON which gets pretty flat.

[hpeer]

I have posted most of my paint saga on the a Metal Boat Society.

I am still not sure if I have fixed the problem or not.

I don't have the boat in the water yet, another jiggling issue.

Short of joining MBS, which I recommend, you could do an a Google search here for Ameron 235, a few threads will pop up.

It's enough to say I can not get consistent advice on Ameron.

But I had other issues as well.