Best products for rust.

[Andrew1974]

Hi what's the best products to apply rust? I've got some on my van and I'd like to slow it down or prevent it.

Thanks

[WarthogARJ]

I am also looking at this.

Sure, lots of stuff claims to convert rust, but try it and scrape it off.
You'll find rust there still.

You need to remove it ideally: down to bare metal.
The various treatments do convert it, but unless it'\s a very small isolated patch it will come back.
Because you need to paint over it, and for that to work, you need a good surface to paint on.

So whatever you do, you need to remove dirt and grease.
Then loose rust.
Ideally anything left, take off to bare metal.

I think sand blasting is the best.
You can buy an attachment for a water jet blaster that works REALLY well.
See this:
[url]https://www.ebay.co.uk/itm/Sandblasting-Wet-Sand-Blast-Kit-Attachment-for-Pressure-Jet-Washer/122906818717?ssPageName=STRK%3AMEBIDX%3AIT&var=423359446623&_trksid=p2057872.m2749.l2649/url]
It fits various pressure jet washers.
Is a cheap copy of the actual Nilfisk etc part, but works OK.
I've used both.
It works by Venturi effect: you put the clear hose into a bag of very dry, and very fine sand.
And connect the other end to the pressure washer, which sucks up the sand and blasts it out.

Leaves a bit of a mess in terms of sand, but is clean sands, easy to wash away.
If you want to work on one area, you can mask off what you don't want sprayed using duct tape etc.

Some chemical treatments are brute force: they just aim to dissolve the rust itself.
Like Naval Jelly.

The converters are all roughly the same: phosphoric acid or tannic acid converts the porous iron oxide to magnetite, which is not porous, and is stable.

A pure converter, you don't need to rinse it off.
One that aims to dissolve the rust you top wash off.

On small areas, and places you don't want to mess with too much, and stuff like nuts & bolts is OK.

[WarthogARJ]

Hah, on a roll.
The issue is that iron oxides (rusts) VERY easily.
And that oxide that forms is both proies to air and water, so the process continues, and it's not very strong: flakes off.
As we all know.

So whatever converter you use aims to try to convert that existing quite stable oxide.
From the surface down.
And if it's a think layer?
Well it converts the TOP, and THAT tends to seal off what is BELOW.
So by its nature it stops itself.

A thin layer will be easier to "convert" than a thicker one.
But if thin, why not just clean off?
Then prime and repaint?

I think rust converters are a short term solution.
But if all you want is a year or so, fine.

A REALLY elegant method would be to take your van to a swimming pool and drive it in.
Add some NaOH.
Connect up the van to a negative (anode) DC source.
And put some chunks of steel in the pool, and connect to the positive (cathode).
Then turn the juice on....
You'll remove the iron oxide by electrolysis.
Voila!!
Just remember to cover the exhaust and air intake so you can drive out when you drain the pool...:-}

[the dutch guy]

I use fertan after going in dry (and hard) with a wire brush on the dewalt.
Take off any rust/dust with those pre-paint-sticky-cloth towels and liberally apply fertan. After the reaction finished hit it with primer and paint from a bottle. Best is to use that red welding primer chemical death-in-a-can stuff. That binds better then regular automotive primer.