Sanding question (rust removal)

[johnlv6]

I have a small patch of rust (about 2"X2") under my passenger side roof rack. What grit sandpaper would be appropriate to remove that?

I'm on a limited budget and just want to fix the area. I just want to make sure the rust doesn't spread. My paint isn't pretty.. It wont hurt my feelings to sand the area down (use body filler in the area if necessary), treat it with a rust preventative spray and paint it. I would appreciate any other pointers you can offer. Thanks.

John

 

[5-90]

240 if you can get away with it, 180 if you can't. If it's a visible area, a little "spot glazing" putty, finished with 400 grit will make it easier to hide the painting when you're done.

5-90

 

[johnlv6]

Thank you.

 

[langer1]

Also you say your paints not pretty so I want to add just don't leave it primer.
It will rust right through the primer.

 

[TheNerd]

Thats true... I learned it the hard way. Most primer ain't ment to stop rust:

This is NOT dirty... about 3 days after the primer was put on and you can see the rust making its way through:

 

[johnlv6]

I'm going to sand all the way around the exposed area to make sure i don't leave any rust (you can see where it's under the paint around the exposed area...causing the paint to have a bumpy look). I'll make sure to treat the area. I'll take your advice and be careful how i finish it off. My rig is black...so most any paint should match (close enough for government work...that is).

 

[langer1]

I'm going to sand all the way around the exposed area to make sure i don't leave any rust (you can see where it's under the paint around the exposed area...causing the paint to have a bumpy look). I'll make sure to treat the area. I'll take your advice and be careful how i finish it off. My rig is black...so most any paint should match (close enough for government work...that is).

Just make sure it's automotive paint.

 

[johnlv6]

Just make sure it's automotive paint.

Gotcha

 

[dizzymac]

Get some "Zero Rust", comes in spray,quarts or gallons...colors too. Do your sanding treat with ZeroRust, and top coat,you don't have to prime it acts as a primer,good thing about it is if you don't top coat it won't rust through like primer.

 

[johncannizzaro]

I would clean it up and try to get it down to bear metal and use etching primer to seal it. Give it a few light coats, then primer and paint.

 

[johnlv6]

Hey guys. I wanted to say thanks for your advice. Between deployments/TDY's and my work schedule...i just got the time to tackle this little project. Here's a couple before and after pics. I think it came out ok considering it's my first attempt at body repair.

The rust went all the way through in one spot (about 1/2"). I had to use liquid metal to fill in the spot. I got to use the new Makita grinder i've had lying around...there was a fair amount of rust to cut through to get to bare metal.

It was pretty straightforward. Sand/grind down, fill the 1/2" size hole, primer (etching primer....the rust preventative stuff), and paint. 8+ hours later and this is the finished product (trial and error process ).

I'd like to have finished it up better...that'll have to wait for a long weekend. Thanks again.

John

Before:

Getting there...

After:

 

[tgoff]

Try some rust mort from sem to chemically stop the rust. Sand as much as you can first then follow directions on bottle should work fine.

 

[johnlv6]

Try some rust mort from sem to chemically stop the rust. Sand as much as you can first then follow directions on bottle should work fine.

You must have perused the first couple of posts . The pictures of the grinding/sanding process didn't come out very well...that's why it looks like i skipped a couple steps.