Engine bay rust - Fertan, Owtrol, other?

[John V]

I have recently (couple of months) used Flag "Rust Converter" on some small rusted areas on Sabina, one with heavy rusting applied after de-scaling and vigorous chipping, thee other with light rusting applied after wire brushing.

I spent a while trying to find the active chemicals in this product but without success. It doesn't smell like a Phosphoric acid based compound and it lacks the warning signs normally present on Oxalic based products. Has anyone else any experience with this stuff?

 

I wasn't too concerned about its effectiveness due to the low risk of the areas treated but I would be interested if anyone else has experience before using more of it, especially in a more vulnerable area.

 

Years ago I was a great fan of Mr Harry Wheatcrofts Tannic acid based product (He of great Rose growing fame). There are a couple of areas on Sabina that I treated with his product and never overpainted and they show no sign of rust after nearly 20 years !!! (interior of hull of course). Unfortunately he sold the rights to "CarPlan" and the price jumped from a few quid per gallon to a few quid per 125mL !!!!

[Tony Brooks]

Ah Flag Rust Converter otherwise known to viewers of the shopping channels as Black Magic. I went through a assimilate process to John and got as far as emailing Flag (no reply) and them telephoning them to try to get the same information. I asked for their technical manager and the lady who answered avoided answering my question, referred to "new technology", and said "it is lovely paint my sister uses it". So no further forward.

 

I have yet to see the colour change the instructions speak off but the lady did warn that if there is any brown in the area it needs another coat.

 

I am more than happy to be proven wrong but I suspect it is another water emulsion that seeks to put a water and air proof barrier between the rusty steel and the atmosphere. I have no idea what makes it black.

 

I also note their data sheet (http://static1.squarespace.com/static/516bc0d7e4b0f727065c77b6/t/516d602ee4b044ac537b6460/1366122542598/rust_converter.pdf) refers to a Safety Data Sheet yet there is not one on their website, aparently you need to phone for it. I am tempting to ask what are they trying to hide.

 

I am trialling it on the hull above the top rubbing strake where the paint is always being damaged. So far, but only for a few months, it ha shown no obvious signs of rust re-occurring but then I would not have expected it if I had used a good metal primer. Time will tell..

 

I just wish such companies gave just a little more information to their customers rather than relying on the "trust me I'm a doctor" principle.

[Sea Dog]

Is it even legal not to have a readily available safety data sheet Tony? I'm thinking you're not wrong to have suspicion.

[David Mack]

Ah Flag Rust Converter otherwise known to viewers of the shopping channels as Black Magic. I went through a assimilate process to John and got as far as emailing Flag (no reply) and them telephoning them to try to get the same information. I asked for their technical manager and the lady who answered avoided answering my question, referred to "new technology", and said "it is lovely paint my sister uses it". So no further forward.

 

I have yet to see the colour change the instructions speak off but the lady did warn that if there is any brown in the area it needs another coat.

 

I am more than happy to be proven wrong but I suspect it is another water emulsion that seeks to put a water and air proof barrier between the rusty steel and the atmosphere. I have no idea what makes it black.

 

I also note their data sheet (http://static1.squarespace.com/static/516bc0d7e4b0f727065c77b6/t/516d602ee4b044ac537b6460/1366122542598/rust_converter.pdf) refers to a Safety Data Sheet yet there is not one on their website, aparently you need to phone for it. I am tempting to ask what are they trying to hide.

 

I am trialling it on the hull above the top rubbing strake where the paint is always being damaged. So far, but only for a few months, it ha shown no obvious signs of rust re-occurring but then I would not have expected it if I had used a good metal primer. Time will tell..

 

I just wish such companies gave just a little more information to their customers rather than relying on the "trust me I'm a doctor" principle.

 

There's a Safety Data Sheet at https://www.promain.co.uk/specsheets/RUST%20CONVERTER-Promain.pdf. According to this it contains aliphatic amide derivate.

[Tony Brooks]

So from that I need to ask what is aliphatic amide derivate and how does it combat/neutralise rust. Any Chemists about who have any idea about this stuff? Thanks.

[Beaker]

So from that I need to ask what is aliphatic amide derivate and how does it combat/neutralise rust. Any Chemists about who have any idea about this stuff? Thanks.

 

I'll ask Bunsen next time I see him.