Rust treatment/prevention

I have removed the rear arch liners and black corner trims near arch liners to check for corrosion, passenger side needs a bit attention but not bad overall. Am I better removing any corrosion with wire brush in a drill or is there a better way of doing it ? Also some of the old coating along the seam of the sill has come away to approx the opening of the door, what is this best treated with, it does look like rust has set in. There is 2 grommets visible per side when I removed the arch liners, I had a look inside but nothing noticeable. Should this be treated with wax oil ? I've not been to the front end so I'll likely have more questions but any pointers at all would be helpful.

I'd been interested knowing this too. Part way though this may help: http://911uk.com/viewtopic.php?t=128526

opcorn: I'm planning on attacking mine with a wire brush on the angle grinder and then some rust neutraliser as a starting point. I haven't thought much past that yet. MC

I did this. Wire wheel in a grinder, a drill mounted one isn't man enough. Remove any loose underseal and rust, all along the sills and anywhere else on the underbody. Any loose underseal will just trap moisture. Use rust converter (I use phosphoric acid gel, most wonder rust products are acid based, some are phosphoric acid). Then your choice of paint / coating (I use por15). I sloshed waxoil over it before refitting the plastic. Pop all the cavity bungs off and liberally spray cavity wax inside. Eugh: Wire wheel: Acid: Por15:

Sand paper -> wire toothbrush -> stiff wire brush -> flappy wheel -> wire brush drill attachment -> grinder Depending on how serious it is, you may have to move along the list. I found a stiff wire brush got most of mine off and I used a flappy wheel/wire brush drill for the larger/stubborn areas. I treated the now 'clean' area with Rust Bullet https://rustbulletuk.com/en/ which claims to dehydrate the metal/rust and then cover it with an inpenetrable layer. It's pretty easy stuff to use so I'll use it again in the future

PS theres a few other places to look for rust.... chassis just behind front subframe mounts. Top of rear arches inside arch Jacking points various seams around the underbody

I've found poly discs on a grinder, or a poly wheel on a drill to be great at fast rust, paint and underseal removal. They seem to be far faster at removing the paint and rust. They leave the metal underneath in a much better condition than equivalent wire brush attachments, which seem to polish the rusty surface and can scratch and damage at the same time. This doesn't happen with the poly discs. The only negative is they are a bit cumbersome. You can get a wide array of wire brush attachments for the drill, which get into the nooks and crannies more easily.

A long time since I've used rust removal products, are they much of a muchness nowadays? There used to be Tannic (e.g. Fertan) or Phosphoric acid and I used to use Kurust as it was a bit gel like and stuck well and also have a high zinc content. Views?

Phosphoric acid is self limiting as it forms a hard ferrous phosphate layer, the blue black colour which will resist further rusting. Citric and hydrochloric acids will continue to eat good metal, and don't form a layer and parts will rust again if exposed. Usually rust converter products are phosphoric, eater products other acid. Check the ingredients / chemicals data sheets, there might be other stuff in there e.g zinc which you may like to pay extra for. The brands and products change every few years so it's hard to make a comparison, but body shops have been using phosphoric for years.

Did you have any problems taking off the corner trim pieces. ie broken or striped threads of fixing screws.

I ended up cutting the corner pieces off as some of the screws the heads were done. I'll source new corner pieces or adapt what I have. Regarding the treatment, what treatment is recommended for treating the rust prior to applying the por15

Just drill the heads off and replace with stainless and new stainless screw tab things.

Hi Wasz Do you know what the 'tab things' are called, I'd like to buy some stainless ones but I don't know what to search for on line? Spire clips, I've found them but they don't seem to do stainless, probably because they're spring steel. thanks Mike

Ebay, Stainless U clips or Chimney nuts https://www.ebay.co.uk/itm/Clip-U-n...hash=item3aef8b67b1:m:m_irjufB_pFlzHentenwYDQ There are plenty of results Drew1209 - You need to degrease the area, then use POR15 metal prep which I think might convert the rust (similar to the acid converters) and also etches any other paint so it will accept the POR15. If the area is exposed to UV light, the recommendation is to top coat the POR15.

I've just started this at the weekend. So far I've ground as much of the rust off that I can get too (not to bad to be fair) I've coated the rust areas with Vactan and I've a tin of silver por15 sitting to go over. Anyone know if I can just cover the Vactan directly with the por15, the Vactan has a primer built into the rust protection I believe. I did wonder if it was pointless using the rust converter as the instructions for por15 state that it can go directly onto rusted surfaces, if using the Vactan with inbuilt primer how can the por15 do its job correctly as it's not in direct contact with the rusted area. I've done inside the sills with dinitrol clear cavity wax (1litre per sill) I assume I would be better with a different coating for covering the arches before refitting the arch liners ?