Paint Touch-up Thread ?

[EdLancer]

Is there a paint touch up thread on Autopia, never was able to find one
Like touch-up rust, paint chips and scratches where you don`t need expensive professional equipment
Would be great if there was one is for both professionals and DIYers that touch on paints, primers and techniques etc...
Most paint forums touch on complete paint overs, but barely any on spot repairs that is geared towards more for us detailers

 

[Accumulator]

There were some good ones....including one where Brad B. did an *incredible* touchup on his Porsche with an airbrush. It`s a pretty broad subject to try to over all at once.

-Clean with proper solvent (not just IPA)
-Treat existing rust (remove/neutralize/convert- pros/cons to each)
-Prime with something that`ll arrest any (seemingly inevitable) residual rust
-Apply touchup paint (single stage? b/c?)
-Level if necessary (chemically? mechanically/abrasively?)
-Correct any marring without removing touchup paint
-Protect with something that`s fresh paint-safe

That`s the thumbnail-sketch version. Filling in the details could result in a decent size book.

 

[EdLancer]

I am currently going through this exercise myself on one of my cars. Rust spots burst out from behind the base/topcoat on the left rear wheel rim.
I did a pretty decent job with just 1k self etch primer, 1k filler primer, basecoat and clearcoat last summer, but after the winter the spots reappeared which makes me come to the conclusion that there was moisture trapped in the primer and with the expansion from freezing cause this new round of bursting. For the past two weeks I tried the same, but this time I can see blisters/bubbles within a day after applying the basecoat/clearcoat and water when I burst the bubbles. I even tried it with dry sanding, but still blisters, but on a lesser scale.

I am going to try this tomorrow and hope the humidity won`t get absorbed using a 2k primer instead of lacquer base 1k primer:
1. 1k self-etch primer to treat the bare metal
2. Apply 2k urethane primer using roll and tip. I know there is 2k urethane primer spray by Eastwood, but it would be expensive to mix a can just for a spot repair which might require additional coats since 2K aerosol has a work window of just under two hours, plus the product is not available locally.
3. Dry sand the 2k primer after 8 hours drying
4. Wipe down with grease and wax remover
5. Spray 1k enamel basecoat
6. Spray 1k acrylic enamel clearcoat.

 

[Stokdgs]

Welcome to the forum, EdLancer -
Hope you enjoy your time here - it is a great place !

Accumulator above, has given you the best process.. ^^^^^^^^^^^^^^

It is important to wipe it all down with a solvent that really cleans all unseen gunk off, and if possible treat the metal surface with something that etches the metal and cleans out all rust that cannot be seen by the naked eye or low power magnification..
When I painted cars, that is how we did everything - rusty or not, to insure nothing got started later underneath the work..

And don`t forget - regular primer does not prevent rust..It does not even prevent water from going through it..
Once your prime, you need to be right after it`s dry, to paint, several light coats, etc...

Like your process..
Eastwood has always made great products for about anything automotive..

Regarding your wheel - it has rust on the outside, I am assuming, right?

What I don`t know is exactly where the rust is on the wheel...on a spoke or something like that... on the front... on the rim part that has the tire covering it...

Have you thought about finding out the source of the rust ?

Could it possibly be coming from the other side of that spot/s ?
If you don`t find the source of the rust and eliminate, it might just keep coming back..

If the other side of the rust is inside the wheel that is covered by the tire, then to really fix it you will have to dismount the tire off the wheel and look at the wide part that holds the tire in place, etc.., and see if the rust has started in there..
Good Luck !
Dan F

 

[EdLancer]

As far as I can tell it is surface rust probably from bad factory prep on the metal. Car is approaching 11 years sitting outside 24/7 through harsh Canadian winters where salt is abundant, but still Autopian in every aspect. The rust spots is on the flat arc of the quarter panel of the rim well.
The thing is once you sand down to the bare metal, you have build the primer back up so you can block sand it flat.
Would really like to use 2K products from the self etching primer, primer, basecoat and even the clearcoat, but for spot repairs like these they are just not feasible or cost effective. So right now I am trying to figure out an affordable way to use 2k products without having to waste a whole aerosol can for just a little spot.
I am using Dupli-Color Self Etching primer on the bare metal and then I will build it up with Pro-Form 2k Urethane Primer/Surfacer before the 1k basecoat and clearcoat. I think the weak link is the 1k Krylon Sandable primer I had been using.

Photo not of my car, but just to show where the rust is and is no where this bad, just two button size spots near the center of the rim well below the crease line where I can blend in the paint. The cause for the rust in the photo is abrasion from the rubber trim rubbing against the paint.

 

[Accumulator]

Ed Lancer- Take a good look from inside the well and make *certain* it`s not coming through from the back side.

Not to knock any products you`re using, but if the problem comes back yet again, I`d attack the rust with something like:

Rust Bullet`s Metal Blast (best I`ve used) to prep the meal/dissolve the rust and then prime with KBS Coating`s Rust Seal topped with their Fusion Primer. Then apply the paint Those specific products have outperformed everything else I`ve tried (and that`s been quite a list of also-rans, dating back to the `70s).

 

[Mr. Slick]

I have done some. Not that good at it and I on,y do this for people I know that fully understand that the outcome will probably be mediocre. That being said, I did one clear coat failure panel on a silver bmw I am really proud of the outcome. I`ll try to find the pics

 

[Stokdgs]

EdLancer ---
How about this ?? Best Rust Remover - Hand-Held Laser Blasts Away Rust
Dan F

 

[EdLancer]

Accumulator - I checked behind the rim well and there is no rust, it looks like the quarter panel is welded in front of the rim well if that makes any sense. I will spray he rim wells with epoxy primer next summer as a preventive measure.

Finding good and affordable car paint products locally here in Canada is a challenge and I am in a big city even so imagine those living in the boonies. We don`t have Pep Boys and places like that. Canadian Tire is basically the go to place for most Canadians. Luckily I am near a CarQuest that cans aerosol basecoat paints and sells 2K primers.

 

[EdLancer]

Stokgs - I want one, but at $53,000usd I`ll have to wait till they sell them on AliExpress with free shipping ! ...LoL

 

[Accumulator]

Accumulator - I checked behind the rim well and there is no rust, it looks like the quarter panel is welded in front of the rim well if that makes any sense.

If it`s not rusted there that`s great news.

I will spray he rim wells with epoxy primer next summer as a preventive measure.

NO NO NO (did I make that emphatic enough?!? ). Use something better than an Epoxy Primer. Even the best ones won`t last if there`s *ANY* residual rust, and I`d bet most anything that there will be. Not sure what you can get up there, but *really*...you need one of the special products that will truly arrest the rust.

 

[EdLancer]

If it`s not rusted there that`s great news.


NO NO NO (did I make that emphatic enough?!? ). Use something better than an Epoxy Primer. Even the best ones won`t last if there`s *ANY* residual rust, and I`d bet most anything that there will be. Not sure what you can get up there, but *really*...you need one of the special products that will truly arrest the rust.

I`ll try to get those two products you mentioned just to have in inventory, but most won`t ship over the border because they are chemicals.
I did learn one thing with this exercise though, 2k primer is awesome for touch ups with it`s high fill !
Dries to sand in 20-30 minutes and won`t react to 1k basecoat and clearcoats. I just used my finger to apply a dab and smooth over the area, let dry and then sand smooth it is like liquid Bondo.