I know this is a little off topic ;-) but I know there are people on this forum who know a lot about this stuff and I have not had much success on other forums. The photos below show where I have tried to address rust that has started mainly on seams in the van (2006 Mercedes Sprinter). At the time I used a wire brush on an angle grinder to take the affected area back to bare steel. In one case I painted Dulux Metalsheild All Surface Primer straight on the surface and then used top coat. It has re-appeared as can be seen below.
Another time I wired brushed back to bare metal as before and then applied rust converter on the rust right inside the seam and then applied several coats of grey car primer from a can straight over the top. When dry I used a spray top coat. I know it looks rough but you can't see the roof ;-)
In both cases the rust has come back, am I doing something wrong, should I be cleaning the bare metal with something before priming. Maybe I am using crappy products?
thanks
Don't use rust converter. You need to remove the rust. Clean it up back to clean steel as best you can and treat the rust to Dioxine {check the spelling but its a phosphoric acid from supercheap/autopro]. Wash it with fresh water and blow dry. Paint with a surface primer and then undercoat and top coat etc. The trick is to get the acid off and blow dried and the paint on as soon as possible. It's all in the preparation.
What Ramona said. I use swimming pool acid from bunnings, let it fizz for 5 mins or wire brush while its on there as well. Wash it with water and dry with clean rags.
Now check for black rust spots and get rid of them ( i gently use a drill for this )
Repeat the acid, water and clean rags then paint. If there is a join with a crevice or bits you cant get at use penetrol as a primer. It soaks in like wd 40 then sets. Any black spots left will eventualy come back.
Hope this helps
Clean the rust completely back to bare metal, use POR 15+ from Permanent Painted Coatings, in Warriewood NSW, including their metal ready prior to the POR. Once that's done, you'll need a tie coat, then your top coat of choice.
Call, them, they're very knowledgeable.
I have no affiliation, but have restored a few bikes and cars with these products.
Phosphoric acid, wipe of with water, wire brush on grinder, repeat ....... When had enough of that game wipe with metho to remove any lingering water then epoxy resin then paint. A bit over the top for a vehicle maybe but I have great results onboard with this method
I like the idea of a blow dry but it would have to be dry air, like a hair drier or a paint stripper, then I would still use metho as it also removes oily contaminants. Though the hot air could help set epoxy.
My other hobby is repairing / restoring old mechanical wrist watches where water moisture is a huge no no..
Short of using specialised cleaners in Ultrasonic machines the fluid used for many decades by watchmakers to clean , degrease parts is Naptha (Shellite) sold by Bunnings ,Diggers brand.
After cleaning immediately blow dry . If a film left ,which should not be, wipe over with clean cloth. Some people use Isopropyl which is marginal as contains higher water %.
I'm having trouble with a little bit of rust in one of my cars.
Will the treatments listed above help me?
You only have a little bit of rust left . But as long as you still have the VIN plate for it and money is no object is definitely restorable.
Looks like my old 180B after removing the vinyl roof, only that one had rusty bumpers as well.
Damm , Should have guessed it was the Pontiac Wagon with the rear corner bracket standing out like dogs ....