I know quite a few people on here use this stuff. I have started wire brushing the front subframe on the beetle and have a tin of combi colour arriving tomorrow. I'm after people's thoughts on whether to paint it straight on or put some rust converter on first? I've also cleaned up the front arms to paint also.
Ive used Vactan followed by Rustoleum and its been fine so far and on places like wheelarches, Vactan > undercoat > Rustoleum.
There is a Rustoleum primer but if you're only talking about small patches of bare metal/Vactan I'd go straight over it with Rusto. After all it is suitable to go on bare metal itself - begs the question "why do they do a primer then"?? Pass.
I hope it's inside as it takes forever to dry... I'm not a fan. I used Johnstones steel cladding It's self priming made by PPG and drys in ten minutes even at low temperatures. I use this every day at work on a seven year turn around and it holds up very well. Sent from my SM-G981B using Tapatalk
Just arrived. I did order Matt black but have received Ral 9005 gloss. Not sure if it will be too shiney now
On a side note I've used the hardhat paint/primer that Rustoleum made it's expensive but fantastic primer
Looking at the data sheets your product COMBICOLOR 7300MS is not really for automotive applications! Only stable up to 90°C and above 60°C discoloration may already occur - etc. A car standing in the summer sun will reach up to 80°C and more - the air cooled engine bay will be more critical. So automotive (not engine or exhausts parts) is typical −40 bis 125 °C. You can buy a lot of things with great promises. But it's better to ask how long it lasted at a car... My own first early experiments with rust protection paints and rust converters at cars lasted less than 1-2 years, than 3-5 years - but that was 40 years ago with just some old used cars. For a steel beam in a well-tempered building it is something different than for a car with extreme temperature ranges and possibly with salt in winter and splash water in summer, etc. Rust converters are pretty much crap - there is no magic bullet. Most of the time it's just cheap phosphoric acid (like in Coca Cola) - which is also used when building paint to roughen bare steel in order to allow primer to adhere. So I also have it in the garage but for bare metal without rust - before every paint build-up. The rust must first be removed mechanically (be careful with wire brushes, which put a deceptively clean shiny layer of their own material over it), making sure that it also reaches deeper into pores in the material (like the iceberg, where you can only see a small part above the water). Otherwise, remaining rust will continue to work. You can only slow it down. Or better just cut it out straight away. I managed to do this quite well more than 25 years ago on my Karmann (still with me and gets moved) with POR-15 products - an US shipbuilding product in Germany also used in the US classic car scene - paints become very hard and are available for different temperature ranges - processing was not easy - too difficult for some, so many dealers threw it out again. It has been also on my bus for over 15 years now (moved a lot also in deserts and snow).
One issue with many rust converters is a lot of them only convert a thin layer of rust to something passive, leaving rust underneath. Hence the need to prep the metal so the rust is only in small pits. Better still are the converters that dissolve the rust in the pits and leave only metal. Then the pits get filled with paint. Otherwise if damp gets in there off it goes again. POR 15 and other hard coats are great until they get damaged then they act as a nice plastic bag to keep water in contact with the metal. (As does any paint layer.. a totally bare sheet of metal often lasts longer than a painted piece of metal once rust starts tracking under the paint.. The worst mess is always under the totally waterproof underseal , while the bald patches in the wheel arches rust slower...) Also POR 15 has a tendency to peel off if there is any grease around so excellent preparation is essential.
Applied the rust remover by brush about a week ago but looks a bit rubbish. I've since discovered it has a shelf life of just 12 months so maybe that has something to do with it I'm tempted to buzz it off a just apply the rustolium. Only issue now is the cold weather, minimum application temperature is 5 degrees.
Phosphoric acid based rust converter only goes black if it finds some rust to convert. On clean metal it will stay shiny. I am pretty sure that the POR 15 version needed a wash down with water as it left powdery deposits (I think its just diluted phosphoric acid) . Read and follow the instructions.. Make sure the shiny metal is properly prepared...or you might end up with everything only sticking to the rough bits.
Why not use proper automotive/ industrial paint? Unless I don't know, Rustoleum is a paint found in home improvement store? On chassis parts, I use polyurethane with hardener. Works really well, got good rustproofing abilities , easy to work with and not so expensive. Check your autoparts store, they should carry a line of this. Wathever brand, they all work. https://www.libertpaints.com/en/producten/industry/dts/cryltane-dts-40
They make all kinds of very good paint and are a very clever chemical company. My most impressive buy was a can of metallic spray that you can paint straight onto aluminium in a few wet on wet coats. I'm impressed not only because it stuck and is still looking great a few years later on my narrowboat window frames (outside) but because I made a run and had to clean it off and repaint. When I did I found this paint had magically layered itself into primer, undercoat, metallic and lacquer, even through several coats each had floated about to form one of each coat in total. Completely magical, I have no idea how they did that.
Didn't knew that, thanks I thought they did oil based paint like the ones found in diy store. Those don't work on automotive parts.
