Vactan vs Owatrol?

[Odana]

The new baby boat has a V bottom with a fair bit of flaky rust in the bottom from leaking roof/front hatch. Otherwise it is very dry and most is sound. Once we've scraped and wire brushed I want to give it a coat or two of something to prevent further rust before the floor goes back down The main vulnerable area seems to be this V bottom in case of future damp. There is also a little bit of rust on the inside of the wall struts which I will do at the same time, though most is fine. There is polystyrene over the walls if this makes a difference.

 

After reading the many threads I am still unsure what to use. Once it is painted and the floor back down, things will get built over the top, so I am unlikely to ever see most of the bilge again other than an inspection panel and pump access. This is what I understand so far

 

1) Owatrol - nice and runny oil and will seep into the little crevices and pits to prevent further corrosion. Can be painted over with primer. Does it have to be overpainted, or is it fine to Owatrol it thoroughly and then leave? I am in favour of whatever requires least coats for most protection! So far this sounds good to me

 

2) Vactan - will convert rust to something else. Can be left on and overcoated. But may not get into all the nooks and crannies as well?

 

3) Waxoil - Like Owatrol but doesn't dry?

 

4) Red oxide - pointless unless we remove all hints of rust first, which will be nigh on impossible.

 

5) Hammerite - was my default option, but reports seem to indicate it's not as good for getting into those crevices.

 

 

Opinions invited on products/combinations.... I hope to get this stuff at/by the weekend to start the first section. The less pristine I have to get the hull first, and the fewer coats of whatever it is necessary to do the job well, the better!

 

Thanks!

Edited February 26, 2013 by Odana

[NB Lola]

I use vactan then cover with hammerite

[Bobbybass]

Only thing about Vactan is that its only really effective on rust.

It doesn't adhere that well to clean metal as it converts the rust into a surface suitable for the top coat. I have found that over large areas with no rust, it has a tendency to eventually start to peal off in a 'skin'.

[GSer]

I use a mix red oxide and owatrol, first i put a coat of owatrol leave it to become tacky then finish with 60% redoxide/to 40% owatrol mix, takes ages to dry but is very hard wearing in my experience. If you leave the initial coat of owatrol to dry fully, paint dosn't seem to stick to the glossy varnish like finish of the fully cured owatrol. ( Adding the red oxide gives you a good indication of coverage)

[smileypete]

If the surface is wire brushed I'd just use any one coat metal/bilge paint that has rust inhibitors. All the big marine paint names do bilge paint, but it might need a phone call to the manufacturer's help line to check they have rust inhibitors.

 

Couple of other ones are Hammerite smooth or Bitumastic coloured solution, a local decorators merchant might be able to order in the latter.

 

For areas with nooks and crannies I'd run in some thinned paint, the manufacturer should be able to say if thinning with white spirit or turps is OK. Vactan is another alternative.

 

Something to bear in mind is that rust inhibiting paints only work as such when applied direct to the metal.

 

cheers, Pete

~smpt~

Edited February 26, 2013 by smileypete

[luctor et emergo]

I used waxoil in part of my hold last year, and it seems to have peeled largely of the bottom already. Very unimpressed with it. I may try vactan next, or just go back to bitumastic blacking. If it works on the outside....

[MtB]

When Reginald's side decks were welded back onto the hull :-/ the newly angle-ground surface was given one a coat of neat Owatrol by Steve the weldy boy 'to keep the weather out'. Three months of solid rain later it was still ever so slightly sticky and the shiny steel underneath was showing signs of rust. I think Owatrol NEEDS to be over-coated with something.

 

I've since given the side decks a single coat of about 90% Raddle Red / 10% Owatrol which one summer and one winter later is still looking immaculate, despite being walked up and down probably hundreds of times.

 

MtB

 

But having read your first paragraph properly now, I'd recommend International Danboline bilge paint. It's AMAZING stuff. Covers absolutely anything and sticks liek the proverbial. It is the only paint I've ever encountered that will actually stick to silicone. I painted Aldebaran's engine room hull with this straight onto rusty steel soaked in oil and diesel and it still looks immaculate three years later.

[Odana]

Hmmm. Dilemmas! There is a fair amount of remaining rust round the nooks and crannies I can't get to and the bits I wire brushed are certainly not pristine, so Vactan would have summat to grip to if it's runny enough to get into the crevices.

 

Danboline on top of Vactan? Is that overkill? Remember this is a 44 yr old Springer hull we're dealing with, so every mm is precious!

 

Only 10m2 of floor max to do, plus maybe 3-4m2 of assorted upper hull.

[swift1894]

I used waxoil in part of my hold last year, and it seems to have peeled largely of the bottom already. Very unimpressed with it. I may try vactan next, or just go back to bitumastic blacking. If it works on the outside....

 

I agree....Waxoil is useless in an already rusty bilge. I spent ages scraping, wire brushing and vaxing out a bilge then applied Waxoil thinned down with white spirit to aid penetration into the metal.

 

The problem is when the bilge gets wet, with condensation, the moisture gets under the skin of Waxoil and can't dry out. It then separates from the metal in large scabs. I mentioned in another post that diesel might be an excellent (although initially smelly) treatment because it really penetrates into the rust and metal.... or maybe any kind of grease that doesn't dry out.

[smileypete]

Hmmm. Dilemmas! There is a fair amount of remaining rust round the nooks and crannies I can't get to and the bits I wire brushed are certainly not pristine, so Vactan would have summat to grip to if it's runny enough to get into the crevices.

 

Danboline on top of Vactan? Is that overkill? Remember this is a 44 yr old Springer hull we're dealing with, so every mm is precious!

I'd only use rust converter in areas where a wire brush or grinder can't get to; deep rust pits, corners, gaps or seams between metal angle and plating.

 

Elsewhere where the wirebrushing is reasonably OK, I'd use the Danboline only, straight onto the metal.

 

ETA Scratch that, looks like Danboline is in fact supposed to be used with a primer, would be be well worth calling them to check. If so I'd try to source a one coat rust inhibiting paint.

 

cheers, Pete

~smpt~

Edited February 27, 2013 by smileypete

[MtB]

ETA Scratch that, looks like Danboline is in fact supposed to be used with a primer, would be be well worth calling them to check. If so I'd try to source a one coat rust inhibiting paint.

 

Correct, but in decades gone by it was used as a 'sticks to anything' product for grubby bilges, and International only added the requirement for proper preparation, primer etc, I suspect, when trades descriptions act came along and gave users the ruight to demand a refund if if failed to stick to the 1/2" of water sloshing around in the bilge. If you use it sensibly, ie. mop up the surplus liquids, it still seems to stick amazingly to wet and/or oily and rusty steel, drying to a durable shiny finish. I find it so good in fact that I'd use it everywhere, if it came in the right colours

 

MtB

 

Edit: P.S. no I don't work for International!

Edited February 27, 2013 by Mike the Boilerman

[swift1894]

Correct, but in decades gone by it was used as a 'sticks to anything' product for grubby bilges, and International only added the requirement for proper preparation, primer etc, I suspect, when trades descriptions act came along and gave users the ruight to demand a refund if if failed to stick to the 1/2" of water sloshing around in the bilge. If you use it sensibly, ie. mop up the surplus liquids, it still seems to stick amazingly to wet and/or oily and rusty steel, drying to a durable shiny finish. I find it so good in fact that I'd use it everywhere, if it came in the right colours

 

MtB

 

Edit: P.S. no I don't work for International!

 

Can it be thinned down to aid penetration?

I don't like paint that is too thick, I don't think it gets into the pores.

[MtB]

Can it be thinned down to aid penetration?

I don't like paint that is too thick, I don't think it gets into the pores.

 

It doesn't need it in my experience, penetration into rust, cracks etc is brilliant when applied neat, but I would image yes if you wanted to.

 

MtB

[KenK]

I used Vactan in the water tank, dried it using an electric heater then two coats of potable bitumin. That was four years ago, had the lid off for an inspection last September, no sign of rust, couple of inches of water still in the tank below the pick up was clear.

 

Vactan is fairly thin seems to get into cracks without a problem but make sure it's dry and turned black before you overcoat it. Our boat was in the water when I did it and the lower part of the tank needed the heater to make it go off.

 

Ken

[smileypete]

Correct, but in decades gone by it was used as a 'sticks to anything' product for grubby bilges, and International only added the requirement for proper preparation, primer etc, I suspect, when trades descriptions act came along and gave users the ruight to demand a refund if if failed to stick to the 1/2" of water sloshing around in the bilge. If you use it sensibly, ie. mop up the surplus liquids, it still seems to stick amazingly to wet and/or oily and rusty steel, drying to a durable shiny finish. I find it so good in fact that I'd use it everywhere, if it came in the right colours

Fair enough, but it's not clear to me whether it has rust inhibiting additives that most metal primers have. Having thought about it, Bondaprimer has a very good track record and Mike/Blackrose has has some assurance from the manufacturer that it can be used on it's own:

 

http://www.canalworld.net/forums/index.php?showtopic=24984&view=findpost&p=414303

 

Sounds like it needs good ventilation when applying, or you could get knocked out or worse.

 

Bitumen in a bilge is a bit risky, if any oil gets down there it'll make an unholy mess, BTDTGTTS . Coal tar epoxy works very well on hulls but isn't easy to overpaint and I'm not sure whether it's healthy to use inside accommodation, like possible odour problems.

 

So, all in all Bondaprimer gets my vote, not too dear if shopping around, could be used as primer for topsides too. I'd use extra coats in areas that look like it needs it, so all the rust is nicely encapsulated.

 

cheers, Pete

~smpt~

Edited February 27, 2013 by smileypete