Jump to content

Rust spots coming through recently treated bilge


Featured Posts

Hello! Just after some opinions or advice on why I might be seeing rust spots come trough my bilges treated as follows: 

 

1. Significant chunks of rust removed

2. Wire brushed and scraped down clean as much as possible

3. Wiped down with white spirit, left to dry

4. One coat of vactan, left to cure for a few hours at least

5. One or two coats of leyland heavy duty floor paint 

 

All done a matter of months ago and now tiny speckles of rust have appeared through the paint. Any ideas why and what my next steps could be?

 

Thanks in advance for any help!!

82C00FEA-12ED-4464-9CBF-7E6375F604E7.jpeg

Link to post
Share on other sites

Looks as though they might be little bits of metal swarf / dust trapped in the paint from wire brushing etc. You might just have got them on the brush from corners and spread them all over the place. Always happens whenever I varnish, specks everywhere. Rust appearing through paint is usually the result of a very thin covering of paint but it sounds as though you have done a proper job on it. I wouldn't lose any sleep on it, just tell everybody its special paint reinforced with steel.

  • Greenie 1
Link to post
Share on other sites

Have you done any angle grinding?  The specks of steel will rapidly tarnish if they are not cleaned off, before or after painting.

Link to post
Share on other sites

4. One coat of Vactan, left to cure for a few hours at least.

 

This is your problem.

 

Did you read the instructions? Absolute minimum 24 hours in hot summer, otherwise 48 hours. 

Edited by matty40s
  • Greenie 1
Link to post
Share on other sites
28 minutes ago, akmext said:

Any ideas why and what my next steps could be?

 

 

Suggest you live with it for the next 5 months and then grind it out, read the instructions, paint it again in accordance with the instructions.

Link to post
Share on other sites
26 minutes ago, dor said:

Have you done any angle grinding?  The specks of steel will rapidly tarnish if they are not cleaned off, before or after painting.


Yes there has been angle grinding nearby since painting so it may well be that - guessing I would just wire brush back and treat again? 
 

Also the rusting specs are localised and not over the whole treated area. 

20 minutes ago, matty40s said:

4. One coat of Vactan, left to cure for a few hours at least.

 

This is your problem.

 

Did you read the instructions? Absolute minimum 24 hours in hot summer, otherwise 48 hours. 


Was done end of Aug so warm enough - I’m all too aware of vactan being ineffective below 10 degrees! 
 

Didn’t realise 24-48hrs required prior to overcoating though - instructions don’t state anything about overcoating time but it would make sense to leave it to cure longer as you’ve said. 

Link to post
Share on other sites
20 minutes ago, Alan de Enfield said:

 

 

Suggest you live with it for the next 5 months and then grind it out, read the instructions, paint it again in accordance with the instructions.


Realistically I’m probably not going to grind it all back again - it’s taken a lot of work to get to this stage given the state it was in prior to any work - and I’m talking sodden with slabs of rust 5mm thick (don’t worry I’m overplated!) 

 

As it’s localised I was hoping to get away with wire brushing affected areas then spot treating with vactan (when conditions are ok) then more of the heavy duty paint over that.

Link to post
Share on other sites
2 minutes ago, Arthur Marshall said:

Can you actually stop a bilge getting rusty?

Without dedicating your whole life to it I think not 😂

 

Im a bit pedantic about most things I do on the boat but, unless you’re starting from brand new or totally gutting an old boat and spending a fortune and/or a lot of hours on it, I think it’s damage limitation! 

Link to post
Share on other sites

I would suggest a proper bilge paint like Danboline. Some floor paints are probably ok, but others are just not suitable for a steel bilge on a boat, so its a big gamble.

 

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

  • Greenie 2
Link to post
Share on other sites
10 minutes ago, dmr said:

I would suggest a proper bilge paint like Danboline. Some floor paints are probably ok, but others are just not suitable for a steel bilge on a boat, so its a big gamble.

 

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

Thanks Dave

In an ideal world that or owatrol is what I’d be using but it’s pricey stuff. I know in most cases you get what you pay for but with such a large area to eventually cover I opted to spend on the vactan and save using the floor paint which is less than half the price. Seems to have done the trick in most places so far 👍

Link to post
Share on other sites
1 hour ago, matty40s said:

4. One coat of Vactan, left to cure for a few hours at least.

 

This is your problem.

 

Did you read the instructions? Absolute minimum 24 hours in hot summer, otherwise 48 hours. 

This ^^^^, and...

 

What made you choose floor paint rather than bilge paint?

Link to post
Share on other sites
1 minute ago, Sea Dog said:

This ^^^^, and...

 

What made you choose floor paint rather than bilge paint?

I’m thinking you’re right - the vactan does need to be left longer... there doesn’t seem to be any instructions readily available about overcoating time though 🤔 

 

And floor paint due to cost - bilge paint isn’t cheap! As an overcoat to a vactan’d surface I thought the heavy duty floor paint would be a good option and have seen some other good reviews from use in bilges. It’s oil and chemical resistant and suitable for use on metal. 

 

Link to post
Share on other sites
6 hours ago, akmext said:

3. Wiped down with white spirit, left to dry

Not sure if it applies to this particular rust treatment but I'm sure I read that white spirit shouldn't be used in the degreasing of the are being treated.  White spirit may prevent the treatment from penetrating the rust.

 

Link to post
Share on other sites
15 hours ago, Arthur Marshall said:

Can you actually stop a bilge getting rusty?

Mine is not rusty, original paint, still OK after 18 years. I would think it was done properly. A light covering of grease and a dry bilge, there is a barrier which stops water getting in from the stern tube, and its a trad stern, no rainwater. 

Edited by LadyG
Link to post
Share on other sites
15 hours ago, Tracy D'arth said:

By floor paint do you mean paint for concrete floors? I would have thought it was not ideal onto steel. It may be slightly porous to allow damp to escape the concrete.

I think you are right. Most of the floor paints that I have checked are actually unsuitable even if they say concrete or steel.  Many are indeed more showerproof than waterproof. I used some on a steel roof. and it lifted when it got properly wet and stayed that way. Took ages to get it off.

  • Greenie 1
Link to post
Share on other sites
9 minutes ago, Bee said:

I think you are right. Most of the floor paints that I have checked are actually unsuitable even if they say concrete or steel.  Many are indeed more showerproof than waterproof. I used some on a steel roof. and it lifted when it got properly wet and stayed that way. Took ages to get it off.

I have seen a roof done with supposedly polyurethane floor paint that peeled off in sheets in the first winter which is why I said it was probably unsuitable in a wet bilge environment. 

Link to post
Share on other sites
16 minutes ago, Bee said:

I think you are right. Most of the floor paints that I have checked are actually unsuitable even if they say concrete or steel.  Many are indeed more showerproof than waterproof. I used some on a steel roof. and it lifted when it got properly wet and stayed that way. Took ages to get it off.

When built, our cellar floor was painted with expensive (supposedly) high quality 'commercial building' concrete floor paint.

It didn't last very long and soon got 'worn' dragging barrels etc across it, it was repainted and was the same again fairly quickly.

The first time the washing machine leaked all over it it bubbled up (almost like paint stripper had been put on it) and it could be 'swept off' the concrete.

 

I have very little confidence on floor paint used in its correct application, let alone on steel.

 

Poper bilge paint is proper bilge paint and is expensive for a reason.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.