Huge puddle of oil beneath engine and some water within it probably around 40 litres worth of liquid roughly

[PhilR]

4 hours ago, Tony Brooks said:

 

and ensure the surface prep is adequate, that is the bit that concerns me about epoxy paints. If there is damp rust pits below the surface then I don't see however good the paint is that rusting will not continue, so the  coating eventually flakes off.

Dry the bilge as much as possible , vacuum out rubbish, then pour in and brush some Owatrol Oil. 

[Tony Brooks]

9 minutes ago, PhilR said:

Dry the bilge as much as possible , vacuum out rubbish, then pour in and brush some Owatrol Oil. 

 

FWIW, that is what I did at the back of y cabin bilge and it looked good at first, within three years or so I was scraping the rust flakes off, de-rusting as best I could, treating with Vactan, and then a couple of coats of Hemple bilge paint. It lasted longer than the Owltrol. Personally, I doubt any coating would last long in this situation with typical DIY prep.

[agg221]

3 hours ago, Tony Brooks said:

 

FWIW, that is what I did at the back of y cabin bilge and it looked good at first, within three years or so I was scraping the rust flakes off, de-rusting as best I could, treating with Vactan, and then a couple of coats of Hemple bilge paint. It lasted longer than the Owltrol. Personally, I doubt any coating would last long in this situation with typical DIY prep.

About the only thing which is likely to is a very high solids aluminium loaded epoxy. However, this is very expensive and not very available (you can buy it, but you have to know exactly where and what to ask for). For most paint systems that are easily available the best you can do is apply it, then a few years later scrape back the rust, leave the good, apply again. Over time you gradually end up getting it all to last fairly well as you progressively deal with the areas where the prep was inadequate.

 

Alec

[blackrose]

On 24/09/2023 at 19:55, agg221 said:

About the only thing which is likely to is a very high solids aluminium loaded epoxy. However, this is very expensive and not very available (you can buy it, but you have to know exactly where and what to ask for). 

 

Jotun 90 epoxy is available in an aluminium flake version. It's about 80 quid for 4 litres and always available from one supplier or another. 

 

https://www.rawlinspaints.com/home/metal-paints/direct-to-metal-paints/5030-jotun-jotamastic-90-aluminium.html

[dmr]

12 minutes ago, blackrose said:

 

Jotun 90 epoxy is available in an aluminium flake version. It's about 80 quid for 4 litres and always available from one supplier or another. 

 

https://www.rawlinspaints.com/home/metal-paints/direct-to-metal-paints/5030-jotun-jotamastic-90-aluminium.html

 

£20 per litre is a very good price for any serious paint. Have you seen the prices for Rylards one pack?

Still trying to understand the advantages of the Aluminium version.

My experience of two pack is it can sometimes detach from the steel in a solid sheet if the prep is not quite good enough, but I am still expermeting and learning.

In general am impressed with epoxy and the slight extra complication over single pack is very much worth it.

[blackrose]

13 minutes ago, dmr said:

 

£20 per litre is a very good price for any serious paint. Have you seen the prices for Rylards one pack?

Still trying to understand the advantages of the Aluminium version.

My experience of two pack is it can sometimes detach from the steel in a solid sheet if the prep is not quite good enough, but I am still expermeting and learning.

In general am impressed with epoxy and the slight extra complication over single pack is very much worth it.

 

Yes good prep is crucial and if you've seen it come off in a sheet it wasn't done right or there was oil or some other contaminant on the steel.

 

The aluminium version of Jotamastic 90 is meant to provide a better moisture barrier and improved abrasion resistance. You can even go one better for abrasion with their glass flake version. I've never used glass flake. I do 2 coats of Jotamastic aluminium followed by 2 coats of Jotamastic black.

 

If you do end up using the aluminium and you're buying more than one can then get one in silver and one in red tone. It's the same stuff just a different colour that lets you see where you're applying the second coat. SML also sell a dye suitable for Jotamastic for about a fiver if you're only buying one can of the paint. I don't know what the dye is called but Rusty used it when his boat was out recently. 

 

Also I'd recommend using winter grade hardener even in summer as the standard grade hardener takes too long to go off after your final coat (about a week at 20C) before the boat goes back in the water. With winter grade it's only about 2 days at that temperature.

Edited September 27, 2023 by blackrose

[dmr]

2 minutes ago, blackrose said:

 

Yes good prep is crucial and if you've seen it come off in a sheet it wasn't done right or there was oil or some other contaminant on the steel.

 

The aluminium version of Jotamastic 90 is meant to provide a better moisture barrier and improved abrasion resistance. You can even go one better for abrasion with their glass flake version. I've never used glass flake. I do 2 coats of Jotamastic aluminium followed by 2 coats of Jotamastic black.

 

If you do end up using the aluminium and you're buying more than one can then get one in silver and one in red tone. It's the same stuff just a different colour that lets you see where you're applying the second coat. SML also sell a dye suitable for Jotamastic for about a fiver if you're only buying one can of the paint. I don't know what the dye is called but Rusty used it when his boat was out recently. 

 

Also I'd recommend using winter grade hardener even in summer as the standard grade hardener takes too long to go off after your final coat (about a week at 20C) before the boat goes back in the water. With winter grade it's only about 2 days at that temperature.

dunno, I quite like the "summer hardener". Its really good to get coats on before the previous one has fully cured and the longer overcoat time can be really useful for this. But, I am talking about using epoxy above the waterline (decks, locker floors etc) where there is no dry dock time pressure

[blackrose]

9 minutes ago, dmr said:

dunno, I quite like the "summer hardener". Its really good to get coats on before the previous one has fully cured and the longer overcoat time can be really useful for this. But, I am talking about using epoxy above the waterline (decks, locker floors etc) where there is no dry dock time pressure

 

Ok in that case you don't have to worry about it. But even with winter grade the previous coat won't have fully cured before you put the next coat on, assuming that's within the specified maximum overcoating time.