What would you recommend for a scratch with some surface rust?

[Suberman]

Hi fellas. What would you recommend for a 1 cm long (maybe 2mm thick) scratch with some surface rust?

After some reading, the following seem to be the way:

sand or rust coverter/killer
prime with either etch primer or epoxy primer
paint

what do you think the best approach to dealing with it?


I'm thinking, sand off surface rust, prime with a zinc rich epoxy primer and touch up paint. Dinitrol 443 is what i'm considering. http://www.dinitrol.co.uk/Portals/0/...43%20SEP09.pdf

Or would a rust converter/killer be more suitable in my case? The scratch is quite small and it's at an area that's hard to work on.

Also, is it possible to COMPLETELY kill the rust and not have it come back somewhere else on the same panel?

Thanks

[Len]

It look like that damage is in the luggage compartment or somewhere else INSIDE the car. If this is the case and it doesn't need to be a "good looking" repair I would probably just scuff it with some 320 to 600 grit sandpaper then touch it up with a brush. If you are going to paint the entire panel and want it to look it's best you should sand it with some 400 to 600 grit then prime it with some epoxy primer and spray the entire panel.

[Suberman]

Hi Len, thanks for replying.

Well, the scratch is along the inside of the sill (right next to the jacking point). Although like you said, it doesn't have to be good looking, i'm trying to do it as neat as possible.

You don't recommend some rust converter/killer products?

The Dinitrol 443 is a epoxy based zinc primer. I'm guessing that should work fine? And stop the rust completely?

You mentioned, touch up with a brush. I'm guessing you mean some touch up paint in a tin on a brush type of kits?

[Len]

Hi Len, thanks for replying.

Well, the scratch is along the inside of the sill (right next to the jacking point). Although like you said, it doesn't have to be good looking, i'm trying to do it as neat as possible.

You don't recommend some rust converter/killer products?

The Dinitrol 443 is a epoxy based zinc primer. I'm guessing that should work fine? And stop the rust completely?

You mentioned, touch up with a brush. I'm guessing you mean some touch up paint in a tin on a brush type of kits?

My guess is that the rust can be sanded off with the paint. If the repair is on the exterior I'd recommend using some primer before touching it up with a brush. Yes, a little touch up kit should do the job.

[Suberman]

My guess is that the rust can be sanded off with the paint. If the repair is on the exterior I'd recommend using some primer before touching it up with a brush. Yes, a little touch up kit should do the job.

Thanks for the advice Len. Before i try it out. do i sand it wet or dry? Do i need to clean the area with some degreaser/adhesive cleaner prior to priming?

Also, i read that epoxy primer is preferable and recommended as it completely seals the area so no moisture gets in whereas some other types of primer is pourous and if not painted over properly would just rust again?

[another2centsworth]

Clean it with rubbing alcohol.
Dry sand it.

[Len]

Thanks for the advice Len. Before i try it out. do i sand it wet or dry? Do i need to clean the area with some degreaser/adhesive cleaner prior to priming?

Also, i read that epoxy primer is preferable and recommended as it completely seals the area so no moisture gets in whereas some other types of primer is pourous and if not painted over properly would just rust again?

That's right clean it, sand it, epoxy prime and paint.

[autobodytech43]

not a big deal. I wouldn't even consider that to be anything to worry about. Cleaning off the rust and covering it up is good enough.

[Suberman]

I've just spent the whole day in search of a "good" aerosol can of primer. I decided on Dinitrol 443 because it's epoxy based and the zinc content. Went down to the shop, and was told that there was only 1 can left and it looks like it's very old. It's even in the old packaging. I believe it's well over the shelf life although the chap assured me that it can be used. i don't feel comfortable trusting a product that's over its shelf life to work. Concern?

Anyway, what about this? http://www.sikkenscr.com/sikkenscr/u...eraerosol.aspx

It's a universal 1K spot primer. Would this work just fine? Sorry to sound thick, but i'm very new to these things. This primer is made up of 'physical drying resins'. Is this an epoxy primer?

The other product that i came across is Dinitrol RC900 http://www.dinol.com/fileadmin/tds/e..._NEW_DINOL.pdf

it's a rust converter with epoxy resin.

Appreciate the help fellas. Just trying to learn as i go along.

[Len]

I've just spent the whole day in search of a "good" aerosol can of primer. I decided on Dinitrol 443 because it's epoxy based and the zinc content. Went down to the shop, and was told that there was only 1 can left and it looks like it's very old. It's even in the old packaging. I believe it's well over the shelf life although the chap assured me that it can be used. i don't feel comfortable trusting a product that's over its shelf life to work. Concern?

Anyway, what about this? http://www.sikkenscr.com/sikkenscr/u...eraerosol.aspx

It's a universal 1K spot primer. Would this work just fine? Sorry to sound thick, but i'm very new to these things. This primer is made up of 'physical drying resins'. Is this an epoxy primer?

The other product that i came across is Dinitrol RC900 http://www.dinol.com/fileadmin/tds/e..._NEW_DINOL.pdf

it's a rust converter with epoxy resin.

Appreciate the help fellas. Just trying to learn as i go along.

The best primer that I know of in an aerosol is U Pol etch primer. hey also make filler primer but I haven't used that. U Pol also makes the best "weld-thru" primer that I've used.

LINK

[Suberman]

The best primer that I know of in an aerosol is U Pol etch primer. hey also make filler primer but I haven't used that. U Pol also makes the best "weld-thru" primer that I've used.

LINK

Thanks for all the help guys.

Len, i'd defintely get a can of those, but from where i'm from, shipping aerosols is not possible.

I've just read the paint technology basics page, wouldn't etch/wash primer lift some of the surrounding paint in my case (spot repair?)

[Len]

Thanks for all the help guys.

Len, i'd defintely get a can of those, but from where i'm from, shipping aerosols is not possible.

I've just read the paint technology basics page, wouldn't etch/wash primer lift some of the surrounding paint in my case (spot repair?)

I haven't had any problems with lifting but I would imagine that it could depend on the stability of the existing paint. If you have a weak substrate like enamel you could experience problems.

[Suberman]

One last question before i attempt my repair. From what i've read, i figured i could use a good 1k etch (wash) primer as well as this is essentially a spot repair? If so, i'll just use some wash primer that my bodyshop spared me.

Also, you mentioned cleaning before sanding and not after? Sounds logical to me to clean the bare metal area with alcohol prior to priming?

Many thanks for the multiple replies. Help much appreicated!

[Len]

One last question before i attempt my repair. From what i've read, i figured i could use a good 1k etch (wash) primer as well as this is essentially a spot repair? If so, i'll just use some wash primer that my bodyshop spared me.

Also, you mentioned cleaning before sanding and not after? Sounds logical to me to clean the bare metal area with alcohol prior to priming?

Many thanks for the multiple replies. Help much appreicated!

Did they give you the acid and the primer separate and need to be mixed before the application? Some etch primers have a time window that they need to be sprayed within after mixing and some don't. You may be able to find the technical info for your primer online if you know the brand.

You should clean prior to sanding so that any contaminants don't get sanded into the surface. It's a lot easier to remove them prior to sanding. Of course the surface also needs to be cleaned right before spraying. We usually clean several times with a good solvent cleaner during the repair and painting especially if the job is in the shop for a lengthy process.

[Suberman]

Did they give you the acid and the primer separate and need to be mixed before the application? Some etch primers have a time window that they need to be sprayed within after mixing and some don't. You may be able to find the technical info for your primer online if you know the brand.

You should clean prior to sanding so that any contaminants don't get sanded into the surface. It's a lot easier to remove them prior to sanding. Of course the surface also needs to be cleaned right before spraying. We usually clean several times with a good solvent cleaner during the repair and painting especially if the job is in the shop for a lengthy process.

Nothing to mix, it comes in a tin, so the bodyshop spared me some. This is a 1k wash primer from Spies Hecker (4085). And yes, i got the technical data sheet online and will be following it. Thanks for setting up the paint technology basics page. Certainly answered a few questions in my head, but I'm curious as to why you would consider a wash primer the ultimate in adhesion and corrosion protection in your paint technology basics page when the general consensus is that an epoxy primer is superior in corrosion protection?