Taking care of rust spots...

[ph001]

I’ve had a small area in the bottom corner of the door that started to bubble very slightly under the paint which I attended to last autumn.

I took it back to bare metal with a dremmel then put a couple of coats of kurust on. When that was dry I covered it with a touch up pen.

All was well for about 4 months but now it looks like it has come back again. Is there a better product out there then kurust or should I just not bother with a rust treatment since I am going back to bare metal and use an oxide primer or maybe an acid etch primer?

I don’t really want to use a rattle can as it’s such a small area and it’s very hard to blend in in my experience.

 

[ph001]

Think I’m going to give the upol #8 acid etch primer a go. Seems no-one on the internet can really decide whether that’s actually better than a zinc oxide or a zinc sulphate, but it should certainly bond well.

 

[buzyg]

The rust is possibly working inside to out. Water getting in via the windows and not able to get out again. If so then you need to solve that first. Don't"t know how though. I have this problem on my little Mazda2. I am treating the symptoms not the problem. Eventually I will lose. But that is a way off yet.

 

[ph001]

Fortunately it's just very light surface rust - pretty sure it's not perforated from inside as you can easily take it back to bright solid bare metal with the dremmel.

 

[john-e89]

Epoxy primers are generally the best for bare metal, Frost do a good range of them in brush or spray.

 

[buzyg]

Fortunately it's just very light surface rust - pretty sure it's not perforated from inside as you can easily take it back to bright solid bare metal with the dremmel.

That's good news. Hard to get a good finish hand painting on an edge like that. You can't really rub it down after painting or your back to metal before you know it.

What you did last time seemed sound, but didn't work. Did you add clear coat. that will at least add a further layer of protection. obviously the trick is to keep the water away from the bare metal, so I'm guessing the paint on your touch up pen is not providing a waterproof layer.

 

[ph001]

I did apply clear coat yes. I think it was more a bonding problem of the basecoat than anything else.

The epoxy primer does sound ideal but I can really justify £30+ for about 5ml of it!

 

[Kernow-Z4]

Check out the Bilt Hamber range of Rust prevention/removal products.
On other cars i've used both the Hydrate-80 all in one cure/primer for a quick and easy repair. For more indepth tinworm the Deox-Gel followed by their electrox Zinc-primer and a topcoat gives a good result.
Both provided excellent results after being somewhat dissapointed by Krust as you seem to be.