Removing Surface Rust

[andsonsvd]

Hey All,

Before I brought my truck it was sandblasted and painted with a red oxide type cover. It has got a lot of surface rust on in.

I used a 60grit sand paper on a DA sander and it worked well but left circular marks, is this ok. Do I need to use a higher grit after to smooth it or will the primer sort this out? it feels smooth.

Thanks Shane

[mknittle]

Originally Posted by andsonsvd

Hey All,

Before I brought my truck it was sandblasted and painted with a red oxide type cover. It has got a lot of surface rust on in.

I used a 60grit sand paper on a DA sander and it worked well but left circular marks, is this ok. Do I need to use a higher grit after to smooth it or will the primer sort this out? it feels smooth.

Thanks Shane

60# is pretty deep i would go over it with 80#

[_Ogre]

60 grit is a little coarse but to get the scratches out will require a lot of metal removal.
they have primer that will fill anything, by the time you get done block sanding the cab,
only the deep scratches will have much primer in them.

prime it, do your body work, rough block it with 150 grit and then decide if you need more primer to fill the scratches.

[andsonsvd]

Ogre,

they are only very small circle marks, you can't even feel them so i couldn't call them scratches?

Ill try the 80 and see what that does

Thanks
Shane

[Kabwe]

You should be using 80 grit. Your primer will fill those 80 grit marks easily and like the others have said 60 is a bit coarse. Also 80 grit will leave enough bite for your filler and primer.

[mr48chev]

I'm inclined to agree that I would go over it with 80 grit before prepping and primer.

It still may take several primer coats and block sanding to get it perfect. This when sanding blocks and long boards come into play and the DA sander gets to rest on the shelf.

[andsonsvd]

So once I've done the whole body back to bare metal with 80 on the DA, I then give it a coat of primer, Sand than re prime using sanding blocks?

Thanks Shane

[Kabwe]

Originally Posted by andsonsvd

So once I've done the whole body back to bare metal with 80 on the DA, I then give it a coat of primer, Sand than re prime using sanding blocks?

Thanks Shane

There are different kinds of primers and reasons for using them.

Bare metal should be protected with at least two coats of a etching primer (old school) or a epoxy primer which is what I use.

You can either do filler on bare metal (old school approach) or do filler over the epoxy and then shoot another coat of epoxy because while blocking your filler will be sure to expose some bare metal.

Then you can move on to your sandable primers be it a reguluar 2k primer, High Build 2k primer, or an poly primer such as slicksand.

[mknittle]

I like the epoxy primer to start with for One big reason is moisture resistance. Once everything is treated and epoxy primed there is one less thing to worry about.

I bet Kabwe remembers the old laqure primers that would get infected if they werent top coted soon enough.

[_Ogre]

the only reason i say to prime it and then worry about your scratches is the scratches are in metal.
the only way to remove the scratches in metal is to remove more metal.
your more inclined to work only the scratch and not the metal around it.
when you block sand it you will find that every scratch is now a low spot.

[OrrieG]

I did my whole truck with 80 grit and 3m purple shredded wheat pads. You want tooth for the primer to grip to. Etch primer is only designed for bare metal, the data sheets say it is not to be applied over paint or filler. Epoxy primer can go over metal, old prepared paint and filler. I does not need to be a hihg build as it is not supposed to be sanded, just a sealer for primers. Most modern fillers are designed to bond to the epoxy primers so if it is put on right no need to use filler on bare metal. Orge is right about removing scratches, they are easier to deal with than a bunch of low spots that might end up needing a skim coat of filler, or sprayable fillers. Look at doing epoxy then a high build primer like Everclear Uro-fill. Look at these pics on painting my hood. Before then black epoxy primer and you could still see some of the scratches from the 80 grit and body file. Hit it with two coats uro fill and it is as smooth as a babys behind ready for blocking.

[TX58]

I used wire cups and 3M fiber disks, Then I use sandpaper to give the primer something to grab to.. Found out you can lose some detail if you go too course sandpaper and a powered sander. The fiber disk really takes the rust off clean.
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[andsonsvd]

Thanks Guys,

The problem is you all talk about the types of discs etc you use but most of them are hard to find in Australia.

can you post a picture of link to the fibre disc you use please.

THanks Shane

[TX58]

http://www.shop3m.com/60440187783.html

This is the kit I used, you can also buy boxes of disk.
Walmart also sells this kit
Posted via Mobile Device

[OrrieG]

These are the 3m purple ones I refered to, I get them equivlent to 80 grit. I use the 4", it is nice because it does not generate enough heat to warp the metal. Do wear eye and hand protection, it does shed pieces at 20K rpm!

http://www.shop3m.com/3m-clean-and-s...x1fnnpnl9.html

[1project2many]

I stripped almost my whole truck plus an extra bed, door, and fenders with 3" bristle disks. They leave a better finish and don't gum up when removing the original baked finish. They will remove metal and they will alter the metal surface but it's nowhere near as dramatic as a grinding or abrasive disc.

http://www.3m.com/product/informatio...stle-Disc.html

Seems like local swap meets are filled with Chinese imitations for all the 3M stuff. The quality's not good but the price is cheap enough so you can buy more.

[mknittle]

[quote=OrrieG;5480803]I did my whole truck with 80 grit and 3m purple shredded wheat pads. You want tooth for the primer to grip to. Etch primer is only designed for bare metal, the data sheets say it is not to be applied over paint or filler. Epoxy primer can go over metal, old prepared paint and filler. I does not need to be a hihg build as it is not supposed to be sanded, just a sealer for primers. Most modern fillers are designed to bond to the epoxy primers so if it is put on right no need to use filler on bare metal. Orge is right about removing scratches, they are easier to deal with than a bunch of low spots that might end up needing a skim coat of filler, or sprayable fillers. Look at doing epoxy then a high build primer like Everclear Uro-fill. Look at these pics on painting my hood. Before then black epoxy primer and you could still see some of the scratches from the 80 grit and body file. Hit it with two coats uro fill and it is as smooth as a babys behind ready for blocking.[/quote
Thanks those look handy

[mknittle]

Originally Posted by TX58

http://www.shop3m.com/60440187783.html

This is the kit I used, you can also buy boxes of disk.
Walmart also sells this kit
Posted via Mobile Device

We have a local tool shop that sells those as seprate parts. he also sells flap wheels to fit that arbor. they work great.