Rust converter?

[katie_hannah]

We have lifted the floor and found the underneath is quite rusty, we've wire brushed it and painted some areas with red oxide.

There's areas that are so rusty we're struggling to remove it (with a wire brush, drill attachment, scrapers), would it be worth putting a rust converter on before red oxide or should we just paint over the rust with red oxide? 

 

Thanks in advance ?

[Duck-n-Dive]

I would recommend using Vactan on all solid rust, then a good Zinc Phosphate primer, such as johnsons high build primer.

An alternative to primer is such as Firwoods 393 machine paint.  This is hard wearing and several coats can be put on quickly as it is very fast drying.

 

https://www.firwood.co.uk/categories/industrial-paints/finishes-and-top-coats/product/firwood-393-rapid-dry-matt-finish/393~393-8000-D

 

Edited July 26, 2020 by Duck-n-Dive

[Dharl]

1 hour ago, katie_hannah said:

or should we just paint over the rust with red oxide? 

Never paint over rust, that will look like you have solved it but will make the situation worse further down the line.    It is worth persevering to get it all up, treat it, then paint it with a couple of coats of Red Ox.    

 

White vinegar works good as a rust remover as well.   

[MrsM]

We have found the best way to get rid of rust is to use 'coarse fleece' pads on an angle grinder.  Toolstation sell them (see link below), but they are a available from welding suppliers at a better price. We used them to scour out our water tank. They were perfect for the job and do not damage the underlying steel. We got though 10 on our very neglected tank. 

 

https://www.toolstation.com/abracs-poly-abrasive-disc/p22693?store=L4&utm_source=googleshopping&utm_medium=feed&utm_campaign=googleshoppingfeed&gclid=CjwKCAjw9vn4BRBaEiwAh0muDKyoeOATojZGWdRm70Q8a_DSPO87hBW-pv4osIA_SqNZtONuBJxjuRoC7nkQAvD_BwE

[dmr]

19 hours ago, Duck-n-Dive said:

I would recommend using Vactan on all solid rust, then a good Zinc Phosphate primer, such as johnsons high build primer.

An alternative to primer is such as Firwoods 393 machine paint.  This is hard wearing and several coats can be put on quickly as it is very fast drying.

 

https://www.firwood.co.uk/categories/industrial-paints/finishes-and-top-coats/product/firwood-393-rapid-dry-matt-finish/393~393-8000-D

 

That looks interesting, might get some and investigate, it looks to be a matte finish red oxide colour top coat (which I like). For floor or bilge protection in a boat Danboline is a tried and tested paint.

 

If the rust is bad and you can't get to bare steel then Owatrol oil, and especially red Owatrol CIP are possibilities, but most people on this forum would recommend a rust converter.

 

..................Dave

[TheBiscuits]

1 hour ago, dmr said:

That looks interesting, might get some and investigate, it looks to be a matte finish red oxide colour top coat (which I like).

 

Just be aware 393 is a xylene based paint, so it's very good at turning other paints into orange peel!

 

Other than that it's great stuff to use and acceptably long lasting.  I painted my gunwales and decks with the black 3 years ago and gave it another coat last year as it was looking a bit tatty in places.

 

Minimal prep needed if you aren't fussy about the finish and aren't overpainting some oil based paints, and available in black, white, red oxide.

[TheBiscuits]

To add: And it's very forgiving of patches that need touching up - you can only tell it's a new bit because it's cleaner than the old bits.

[dmr]

Thanks, I currently use Bondaprimer as a final top coat on decks and 'gunnels as its matte so less slippy in the rain, and I like the colour. So a couple of coats of raddle (which is silk so a little slippy, especially when new, but thick and strong), then bondaprimer on top. 393 might be a better option. Pretty sure Bonda is also Xylene and its fine as long as the paint under it is totally dry.... which means 3 sunny days rather than 24 hours.

 

................Dave

[katie_hannah]

Thank you everyone, I'll look into those things ?

 

[Tracy D'arth]

On 27/07/2020 at 12:10, dmr said:

Thanks, I currently use Bondaprimer as a final top coat on decks and 'gunnels as its matte so less slippy in the rain, and I like the colour. So a couple of coats of raddle (which is silk so a little slippy, especially when new, but thick and strong), then bondaprimer on top. 393 might be a better option. Pretty sure Bonda is also Xylene and its fine as long as the paint under it is totally dry.... which means 3 sunny days rather than 24 hours.

 

................Dave

Bonda is Xylene base, allow plenty of time to dry right through before putting anything else on top.

[dmr]

11 minutes ago, Tracy D'arth said:

Bonda is Xylene base, allow plenty of time to dry right through before putting anything else on top.

Bonda dries really quick, a few minutes, and is really dry in a couple of hours. I have had no problem putting stuff on top. What does go very wrong is if you try to put Bonda on top of enamel that is not fully dry, and fully dry means 2 to 3 sunny days, not just 24hours. Also if you feather an edge in enamel paint (like when repairing a scrape) and put Bonda on then it will sometimes raise up that edge. Good stuff though.

 

I did my front and back decks in surface tolerant epoxy primer, abraded it to take away the shine, put a coat of Bondaprimer on top then two coats of Craftmaster raddle. Decided it was a bit too slippy so put a top coat of Bondaprimer on. looks good to me (but I like the way it fades) and works well. Top it up with a quick new coat of Bonda every couple of years.

 

...................Dave

[Duck-n-Dive]

I used 393 on the rear deck of my "project" boat in the boatyard.  Two coats, no primer 2 years ago and it is still there

As an experiment I overcoated it with Rylard 2-pack blacking with no reaction.

I then overcoated that with 393.  No reaction

Just to complete the experiment, a further coat of 2-pack.

Over the last year the 393 - 2 pack - 393 - 2-pack - 393  sandwich has remained solid with no reaction despite being walked on many times, so I conclude that 393 and 2-pack are compatible. 

I will post a photo next time I am at the boatyard if I remember.

However, I am not sure that "overcoated" is a word, maybe I have just invented it.?

Edited August 2, 2020 by Duck-n-Dive

[TheBiscuits]

1 minute ago, Duck-n-Dive said:

However, I am not sure that "overcoated" is a word, maybe I have just invented it.?

Anorak ...

[Duck-n-Dive]

38 minutes ago, TheBiscuits said:

Anorak ...

No, I believe that somebody has already invented that word...

[ditchcrawler]

6 hours ago, Duck-n-Dive said:

I used 393 on the rear deck of my "project" boat in the boatyard.  Two coats, no primer 2 years ago and it is still there

As an experiment I overcoated it with Rylard 2-pack blacking with no reaction.

I then overcoated that with 393.  No reaction

Just to complete the experiment, a further coat of 2-pack.

Over the last year the 393 - 2 pack - 393 - 2-pack - 393  sandwich has remained solid with no reaction despite being walked on many times, so I conclude that 393 and 2-pack are compatible. 

I will post a photo next time I am at the boatyard if I remember.

However, I am not sure that "overcoated" is a word, maybe I have just invented it.?

2 Pack without blasting back to bright steel, its not possible

Edited August 2, 2020 by ditchcrawler

[Duck-n-Dive]

It is more than possible. It happens and it works.

[Tracy D'arth]

20 minutes ago, ditchcrawler said:

2 Pack without blasting back to bright steel, its not possible

Yes it is, I've done it. 

Hand scraped a 10 year old hull of bitumen, antifouling and gloss paint. Two pack ( Leigh's)  on and 20 years later its still on.

Killer job though, ruined my nails.

[Duck-n-Dive]

15 minutes ago, Tracy D'arth said:

Killer job though, ruined my nails.

You should have got some false nails - works a treat ?

My mistake in a previous post, I used Hempel 2 pack, not Rylard

[BEngo]

1 hour ago, Duck-n-Dive said:

You should have got some false nails - works a treat ?

 

If you get the carbide tipped ones you can shape them up to get into the pits a treat.  Easiest with a diamond nail file.

N

[captain birdseye]

On 27/07/2020 at 09:49, dmr said:

That looks interesting, might get some and investigate, it looks to be a matte finish red oxide colour top coat (which I like). For floor or bilge protection in a boat Danboline is a tried and tested paint.

 

If the rust is bad and you can't get to bare steel then Owatrol oil, and especially red Owatrol CIP are possibilities, but most people on this forum would recommend a rust converter.

 

..................Dave

Just what we did on our boat. Owatrol on leave for a good few days to dry off and then Danboline. Did the bilges four yeards ago, and if I wipe off the accumulated dirt and greasy water under the stern tube it still comes up shiny grey 

[dmr]

8 minutes ago, captain birdseye said:

Just what we did on our boat. Owatrol on leave for a good few days to dry off and then Danboline. Did the bilges four yeards ago, and if I wipe off the accumulated dirt and greasy water under the stern tube it still comes up shiny grey 

I did the very back bilge under the stern gland like this, poor access so very limited prep, and in winters its always wet with collected condensation. I used red Owatrol (CIP?) and then Danboline (or possibly the Rylard equivalent). Its just starting to fail now after almost ten years.

 

...............Dave

[captain birdseye]

Also, when on dry dock I did the inside of the weed hatch the same. An oft neglected part of the boat

 

[dmr]

17 minutes ago, captain birdseye said:

Also, when on dry dock I did the inside of the weed hatch the same. An oft neglected part of the boat

 

I did inside the weedhatch with a very light grey surface tolerant epoxy, this makes it a lovely light place when I have  to my head down there ?

 

.............Dave