Pitted rust help..

[Ben_SaxoForte]

OK so I am doing a pretty much bare shell rebuild on the saxo but I'm having a bit of a nightmare with the rust. All of the soft rotted bits are going to be cut out and replaced but I'm having some issues with the underside of the boot floor, basically it's still solid metal but it has some light pitting in areas. I have cleaned all of it up with a angle grinder and wire brush then used phosphoric acid before coating it with POR15 which I thought had done a great job until I checked it again yesterday and the rust is seeping back through in the pitted areas. Is there anything that is going to stop it? I've heard of deox gel being good but does it really work long-term?

[VeiRoN]

I had the same problem on the rear chassis rail near the tow hook,altough I seemed to have found a way to fix it.

To start removing the rust I've used various wire brushes on a drill and then used Deox-Gel and left for 48 hours with cling film,sometimes it required a few applications,once that was done I've used 2 coats of Electrox by brush,all good on the smooth metal and most of the pitted metal as well but after a few days tiny little bubbles of rust started showing trough the paint in some places (don't really know how to call them),see pictures:

http://i1060.photobucket.com/albums/t445/RaGev4/DSC_0069_zpstanwbimd.jpg

http://i1060.photobucket.com/albums/t445/RaGev4/DSC_0092_zpsjmvufryx.jpg

What I did was put directly the Deox-Gel on top of these spots,left for 48 hours with cling film,cleaned,degreased and painted again with a new coat of Electrox,so far after around a week the "defect" hasn't shown up,I will try this on a few other areas as well that have the same problem,besides that I would always suggest to have a 1L can of Deox-Gel nearby when derusting,it makes everything much easier especially with heavy rust.

[Ben_SaxoForte]

Thankyou for the reply, I will get myself some deox gel and give that a try then, looks to have done a good job on your photos.

[Bedford126]

You literally cannot get rid of rust unless you cut it out and weld in new metal. The products you mention are ok but they are more of a mask.

The way to do it is grind, wire brush clean as deep as you can go. Then heat the panel up for 10 mins to around 70 degrees, you want to dry out all the moisture in the pits this is what causes the rust to bubble back through. Then once dry and hot you want to give it a wash coat with the phosphoric acid. Then mask off the area and use sikkens 1k wash etch primer.

Then do your body work as normal. Just be aware all the water based rust treatments add moisture to the rust so literally make the problem worse by their nature.

[willsy]

It's tough going but so far I've had good success with the Deox gel. Have a look at the last few pages of my 309 resto thread

[Ben_SaxoForte]

Ordered some deox gel yesterday so just waiting for that to turn up now, definitely a lot more rust on the shell than I originally thought, its surprising just how much the rubberized underseal can hide!

Now i'm just struggling with not being able to find a new inner wing for the passenger side front. Going to try and repair the one that's on it but I think it might be too far gone.. the drivers side was just a crumbled mess :( but luckily there are replacements available for that side.

[Bedford126]

Try these guys, they got me out the shit with a couple of old Honda parts and I know they stock a lot of stuff for the Saxo. You would have to sort your own post out and the likes.

Mount panels 0113 2360 360

[VeiRoN]

Thankyou for the reply, I will get myself some deox gel and give that a try then, looks to have done a good job on your photos.

Sorry just seen this,actually in the pics it's before the work,you can see some little spots of rust in the pitted area,to try and fix it,as I wrote,I tried with the Deox and it seemed to have worked so far,just a note to avoid confusion.

[Ben_SaxoForte]

Oh yeah I see what you mean now :) I got the deox gel haven't had much chance to do anything with the car though and it's been a bit cold and damp to be messing with paint I think..

[VeiRoN]

Let us know how you get on with it. :y: