Taking care of rust spots...

Claying, polishing, waxing... share your secrets in here.
Post Reply
User avatar
ph001
Lifer
Lifer
Posts: 3729
Joined: Mon Oct 31, 2016 5:53 pm
Location: N. Yorkshire.

Taking care of rust spots...

Post by ph001 » Sun Feb 21, 2021 9:11 pm

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.
5444FBB8-700A-4EB7-8537-A342E330925F.jpeg
5444FBB8-700A-4EB7-8537-A342E330925F.jpeg (110.24 KiB) Viewed 285 times
55E3D5C0-9E95-4186-BF19-D103868AB285.jpeg
55E3D5C0-9E95-4186-BF19-D103868AB285.jpeg (220.71 KiB) Viewed 285 times
C480FE4F-FE2E-452A-8967-D48374929966.jpeg
C480FE4F-FE2E-452A-8967-D48374929966.jpeg (107.87 KiB) Viewed 285 times
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

Image

User avatar
ph001
Lifer
Lifer
Posts: 3729
Joined: Mon Oct 31, 2016 5:53 pm
Location: N. Yorkshire.

Taking care of rust spots...

Post by ph001 » Mon Feb 22, 2021 8:38 am

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.
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

Image

Online
User avatar
buzyg
Legend
Legend
Posts: 20425
Joined: Fri May 20, 2011 6:11 pm
Location: Cornwall

Taking care of rust spots...

Post by buzyg » Mon Feb 22, 2021 10:14 am

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. :)
Image

User avatar
ph001
Lifer
Lifer
Posts: 3729
Joined: Mon Oct 31, 2016 5:53 pm
Location: N. Yorkshire.

Taking care of rust spots...

Post by ph001 » Mon Feb 22, 2021 12:40 pm

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.
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

Image

john-e89
Lifer
Lifer
Posts: 8617
Joined: Tue Feb 10, 2015 10:27 pm

Taking care of rust spots...

Post by john-e89 » Mon Feb 22, 2021 1:22 pm

Epoxy primers are generally the best for bare metal, Frost do a good range of them in brush or spray. :thumbsup:
M roady...OEM CSL’s, strut brace, Remus back boxes, ZHP, Intravee.
MR2 MK 2
E89 35i project car...mapped 365bhp, M4 stoppers & wheels, KWV3’s, H&R front ARB, M3 front arms, strut brace, Eisenmann cat back race exhaust, VRSF downpipes inbound.

Online
User avatar
buzyg
Legend
Legend
Posts: 20425
Joined: Fri May 20, 2011 6:11 pm
Location: Cornwall

Taking care of rust spots...

Post by buzyg » Mon Feb 22, 2021 8:24 pm

ph001 wrote: Mon Feb 22, 2021 12:40 pm 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.
Image

User avatar
ph001
Lifer
Lifer
Posts: 3729
Joined: Mon Oct 31, 2016 5:53 pm
Location: N. Yorkshire.

Taking care of rust spots...

Post by ph001 » Mon Feb 22, 2021 9:40 pm

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!
2007 E85 Z4 3.0Si manual :driving:
19" CSL's | Eibach Springs | Aeroskirts | Z4M front bumper | Clear brake light | ZHP | RCH+| Stubby

2004 E46 M3 coupe manual - gone but not forgotten.

Image

Post Reply