Rust treatment

[Kevin H]

I have used many different products to treat surface rust and rust pitting, prior to painting, but I can't really point to a product that I know for certain is better than anything else.

Can anyone recommend any products, preferably based on experience over time - meaning a product that you have used to treat rust with long term success.

[geo]

Kevin,

Oh that there was a straightforward answer to this perennial problem! The one that I have used in the past to some effect is Jenolite (the watery remover not the converter), multiple applications with a bit of encouragement from a pad of wire wool seems to do the trick.

It depends upon the severity of course, but to my mind, there is nothing better than blasting the rust with an appropriate grit, then sloshing the Jenolite over the results until all signs of the rust have disappeared.

I am less keen on the converters that claim to seal the rust. On a couple of experiments I made they seemed to work, but when flexing the test pieces a week or so afterwards, there was an unhealthy amount of rust that had been sealed under the black coatings.

If you can get hold of some phosphoric acid of a decent strength, then this is a very much cheaper way of buying the basic ingredients of most of these products.

A link to one of the 'Practical Classics' tests is
http://www.rust.co.uk/filestore/Prac...erter_Test.pdf
but I did not see the follow-up, which of course is the vital part of any test.
Good luck

[Kevin H]

Thanks George. I know what you mean about the rust converter. It's amazing that it's so popular. Probably down to good marketing of a quick fix!

The rust in question is nothing serious, just surface with a small amount if pitting, but it's not feasible to sand blast it.

I believe I do have a small amount of phosphoric acid in the form of Deoxidine 624 (in a jar somewhere!), however I'm aware that if you don't clean the area well enough after applying it then it may keep eating away, and one area I need to treat is a lap joint in a wing bay. Also deoxidine is not a sealant or protector, so the treated area needs to be painted promptly - they recommend within 4 hours!

It's a matter of deciding which is the worse of two evils!

[Geoff Kingston]

Kevin,
I have used lots of paint, converters and waxes over the years and have come to the conclusion that of the treatments available now POR15 is the best by far.
In areas such as wheel arches subject to abrasion it needs like most paints an annual check and touch up at least in our climate, but away from that in areas such as boot floors spare wheel wells etc it is very hard wearing and water resistant. Overcoated with Dinatrol wax and you have a very effective rust control system.
Having said that in your location either the paint or the wax on their own should halt any corrosion.
There was another paint treatment as called corroless or something similar available from Eastwood which was very good if not better, but now this at least in the UK is difficult to find but is I believe re branded still available from suppliers to the offshore oil industry.
Geoff.

[geo]

Originally Posted by Kevin H

one area I need to treat is a lap joint in a wing bay.

Kevin,

Have you thought of using Fluid Film? It is fantastic at penetrating joints and the like. It is interesting to inject this into a box section and notice quite how much of it flows out through apparently sealed joints in a way that other forms of such gloop do not.

The disadvantage is that areas you treat require re-treating every year or two as it does dry out. It is not intended for use where it will be abraded with road detritus,however, it re-envigorates such products as Dinatrol (which does not protect once is has dried out).

George

[Geoff Kingston]

What ever you do don't use Epoxy Mastic , I had read very good reviews about this paint in the classic car press and decided to give it a try alongside its associated rust converter from the same supplier, last year or the summer before I cleaned prepared and treated the underside and inner side of the chassis on on of my 401's with this system, the paint itself is mixed with a hardener on a 50/50 basis and I applied it with a brush which was hard going as it was a thick consistency, a bit like brushing something with tar but it cured to a hard dry finish with good coverage which seemed to have promise.
However less than 2 months later two areas of it simply fell off, I put it down to local contamination but could not work out why as a very dry surface rusted chassis had been fully wire brushed before treatment.
I went over the whole of the rest of it to check adhesion and all looked ok, the exposed areas I painted with another paint.
The car has not moved from my lift since as work has been on going, yesterday I decided it was time to apply Dinotrol wax to the underside, while doing this I noticed a few areas looking odd, you can imagine my frustration and dismay when I discovered that this much praised rust protection paint was peeling off the chassis in some areas like sheets of paper, four sections about 2 to 3 inches x 6 inches, now with wax everywhere repainting was not really an option so the exposed areas where treated with wax.
Returning to the job today to finish off a few areas I could see another section where the air pressure from the sprayer has started to lift this blasted paint, exploring the situation with a scraper easily removed a section of the Epoxy Mastic the full width of the chassis rail and a length of about 8 or 9 inches, again now wax treated.
I did not want to spend days removing the wax with white spirit never mind the cost of wasted materiel and even more time removing the remainder of this useless paint from the chassis, all I will do now is carefully monitor the situation and retreat as needed.
This material was put on absolutely as per the instructions in the middle of the summer, despite all the hype in the classic car magazines it has turned out to be one of the worst rust protection paints I have ever used.

[geo]

Yes Geoff, I have also not had much luck on a longer-term basis with different forms of coatings that have been hyped by the Classic Car press. A few years ago I carefully shot-blasted the steel wheel arches and spare wheel/battery carrier of my then 412 and coated them with a light rub-over of Jenolite. When dry, I then poured or sprayed Fluid Film into the other side of the joints (it gushed through the welds), followed by the application of a coat of the thin Dinitrol and then finished with the thick black Dinitrol.

The black Dinitrol does benefit from an annual lick of the thin stuff to keep it flexible. I only owned the car for another five or six years, but in that time all the former rusty areas did not show any further signs of rust reappearing.

George

[Geoff Kingston]

George,
Have never tried fluid film but I find the Dinotrol waxes good but as you say subject to an annual check and lick over.
POR 15 as a base paint I have found very good, though not everyone likes it and like a lot of these paints it works better on old surface rusted steel rather than new metal.
I used to use Bonda Primer and painted the majority of a 401 chassis with that over 30 years ago, it only now is getting to the stage where it needs repainting, the car though has never been back on the road. Corroless was also very good but so easy to find now through car restoration suppliers but specialists who supply the marine market stock it which hopefully means it is still a good product.
When my S Type had all the body rust cut out about 5 years ago the whole of the underside was waxoiled and that has stood up very well.
Though this time of year is not the best to be applying paint to bare metal, I try to avoid wet damp days, I think the key to a lot of these treatments is
an annual check and retreat any areas as needed.
My late father had probably one of the oldest Mazda B1600 pickups left on the road in west Wales, he eventually wore everything out on it except the chassis which every year was sprayed with waste oil, scrape that off and underneath it was still perfect.
The same was true of a Land Rover I bought a few years ago all the bits of the chassis that had benefited from long term oil leaks were perfect while most of the rest needed attention. Over Christmas the new bits will be sprayed with oil as well, not what I would use on the Bristol but horses for courses.
Geoff.