Fertan rust converter

N

NickT2

New Member
Joined
26 Feb 2008
Messages
1
Visit site
Has anyone had experience of using this product? It has been recommended to me for use on my iron ballast keel after wet-blasting and before priming, but I've no idea if it's better than conventional dry-blasting followed by epoxy primer. I'm suspicious of creating a chemically-induced extra skin between iron and paint.
 
I have used it to treat rust in cars and found it very effective if several repeat applications are made over a period of time.

For your keel have you looked at Jenoseel?

Really though you should follow the recommendations of the manufacturer/supplier of the coatings you intend to apply .... to the letter!
 
I'm sure there are lots of good products but they always seem to involve a lot of work. I used to slap on Hammerite on the worst bits and this worked very well for me.
 
I've found Fertan works well. My strategy is to paint it on to the newly bared metal, then wash and wire-brush it off again 24hrs later immediately before the first coat of primer. I find it best to do this even if grinding/blasting has left what looks like a perfectly clean surface after rust removal. Fertan will loosen remaining particles of rust for the wire brush to sweep away, and hopefully neutralise any that are still there. The wire-brush also helps key the surface for paint. I agree completely not to paint direct over what's remaining that hasn't been converted - that is a recipe for trouble.
 
Good product that has its uses although a chemist friend says that all it does is convert red rust to black rust but maybe he is biased as he works for a paint company!! However I am not in favour of wire brushing especially after blasting / grinding as it "softens" the profile of the cast iron reducing the coating adhesion
 
[ QUOTE ]
I must have had a duff bottle, it did nothing at all!

[/ QUOTE ] It appears to do nothing to rust free metal. The reaction with rust should be quite obvious.
 
[ QUOTE ]
However I am not in favour of wire brushing especially after blasting / grinding as it "softens" the profile of the cast iron reducing the coating adhesion

[/ QUOTE ]It is supposed to convert rust to ferric tannate, a black, water-soluble compound once used as ink. As you might expect, this can be rather messy. 'Black rust' to my understanding is just burnished rust, caused by inadequate mechanical removal.

I should have said that I have an old mild-steel yacht. Its a while since I had to treat cast-iron keels, they were quite a bit easier and less prone to recurrence of rust. An 11000 rpm angle-grinder wire-brush does seem to work for me in reducing shine and keying the surface prior to repainting, but what do you do?
 
Re Fertan In a roundabout way you have answered your own question, ferric tannate, "a water soluable compound"
what do you not want between the coating and the steel? a water soluable compound!!!
Depending on what type of coating has been applied ie epoxy or conventional single pack requires a different approach Underwater/topsides epoxy scheme, remove A/F / topsides finish from epoxy primer, including overlap area, using disc and scraper or blasting then coat immediately with an epoxy blast primer then build paint film using the appropriate primers /tie coats for topside / underwater to the paint manufacturers suggested film thickness.
Single pack products, prep would be the same and overcoating tolerances not so crutial, especially if low temperature is involved!!
As a professional paint inspector I would would ask for a reblast if a blasted surface was touched with a wire brush
Waterbased primers are allowed to "ginger" and be swept with a sweeping brush, nothing harder, should the first primer coat not be applied immediately.
 
Welcome to the forum!
I would avoid any rust converter for marine use and especially underwater.
No subsequent coating will form a good bond to a converter and you can expect corrosion to start immediately and break through your priming scheme pretty quickly.
There is no substitute for dry blasting and a good anticorrosive. Wet blasting is not so good but acceptable as a secondary method of preparation provided, again, the surface can be dried and a good anticorrosive applied as soon as possible. Anticorrosive doesn't have to be epoxy as there are high performance alternatives. For cast iron, expecially if wet blasting, a zinc rich primer is advisable.

If you must use a rust converter make sure it is fully removed before putting any coatings on the keel.
 
Zinc coatings below the waterline? not saying it doesn't work but sophisticated electrical systems to stop electrolosis problems need to be put in place. what appears to happen is if the non zinc epoxy primer coatings are breached, even pinholes, the zinc coating becomes an anode and starts to deplete causing blistering
Have seen more problems using hot sprayed / cold applied zinc coatings below the waterline than I have seen success stories Would happily suggest for topsides, deck and hull, to within 150mm of the waterline, to be coated with zinc and conventional U/W epoxy anticorrosives from just above waterline to keel
For ease of application the modern vinyl aluminium anticorrosives systems applied at the correct film thickness will give excellent results.
 
Not quite, Fertan lays down a zinc phosphate layer on the underlying steel and then the surface above, the rust, is converted to Hopeite ZN3(PO4).2 4H2o and phosphophyllite ZN2Fe(PO4).4h2o . Fertan manual page 15. All these are insoluble in water.

I've been using Fertan on steel boats since 1981 and don't have any problems. I paint it on, give it 48 hours, rinse off surplus with water, allow to dry and then paint.
 
Hello NickT2,

I'm also interested in the rust transformation product, but I'm currently confused about it myself. However, thank you for your suggestion and I will try this product to see how it works. However, if anyone can share their opinion on this product from corten plus, it would be a great help to me in dealing with the rust.
I'll link it here for those who want to help me: Rust Converter
Thank you so much,

Anma
 
Ok, rather old thread dating from 2008, or did you just join YBW to advertise a product under the guise of asking for help :rolleyes:

Fertan? lovely stuff, splash it all over like Brut 33 :)

Turns rust into a hard black surface which once dry should be followed by lots of coats of paint. I prefer Internationals Primocon as it dries quickly enabling more coats but there are lots of other options. However, we normally only patch paint the rusty bits rather than the whole keel or both in our case.
 
Pete7 said:
Ok, rather old thread dating from 2008, or did you just join YBW to advertise a product under the guise of asking for help :rolleyes:

Fertan? lovely stuff, splash it all over like Brut 33 :)

Turns rust into a hard black surface which once dry should be followed by lots of coats of paint. I prefer Internationals Primocon as it dries quickly enabling more coats but there are lots of other options. However, we normally only patch paint the rusty bits rather than the whole keel or both in our case.
Click to expand...
Daughter used it on the cast iron keels of her bilge keel Pandora. She wire brushed with rotary brush in an angle grinder and then applied Fertan. Washed off with fresh water and then Primacon and anti-fouled. No problems two years later.
 
Goodness me, I've just seen the price of Fertan. If you were thinking of spending that much money, time and effort it would be far quicker, cheaper and more effective to do the job properly with an epoxy coating. My personal favourite is Jotun Jotamastic 90 Aluminium. Others are available depending on preference.
 
I use Vactan on bits of cars, campers and boats. Seems to do a good job.

I don't know if Fertan and Vactan are similar or completely different but I am happy with results
 
You must log in or register to reply here.

Share this page

Top