Rock chip...with rust

C

CocheseUGA

New member
Thanks to all the recent heavy rains (500 year floods, that's all), I haven't had the opportunity to care for the car. On Saturday, I finally got an opportunity to wash, and noticed the rock chip I had seen a few weeks prior was actually much worse than originally thought, and had gone all the way to the metal. Now there's rust in that eraser-head sized spot.



Unfortunately, a hood replacement or strip and repaint is out of the question tat this point and time. Are there any DIY alternatives? I just got my PC, but I have zero experience. Basically, I'm okay with treating it and actually fixing it some time down the road when expenses like roof repair is off the table. I don't want it to spread under the paint or eat through. If there's a way to inhibit it, I'd be very interested in knowing.
 
You need to sand off the rust, prime it, and touch it up. You probably won't like the way it looks, but it will look better than a rust spot and it will stop spreading.
 
They make special sanding tools for this. Some guys use a hole punch to cut out pieces of sandpaper and glue them to the eraser end of a pencil. There are some threads on here that you may be able to find.
 
CocheseUGA- You should be able to do this OK (not perfectly, but OK).



Mask off the surrounding areas.



There are "rust pens" that have abrasive filaments made out of fiberglass, these are used to "erase" the rust and will get most of it. These days I get mine from a catalog called "MicroMark" (do a google and you'll find their site). They sell large and small ones, I'd get both.



Then treat the exposed area with a rust converter. With my fave now off the market, I'd go with the stuff from Eastwood Company: Auto Tools, Body Repair, Classic Car Restoration, Paint Guns, Powder Coating, Soda Blasters, Fender Rollers . For small areas, it'll work OK as a primer but using a real primer is better.



A great primer is Eastwood's Rust Encapsulator, but it can have issues when topped with a lacquer touchup paint, and most all of them *are* lacquer.



Then touchup paint/etc. per usual.



The above is *NOT* as good as spot-blasting or other more professional approaches, but it's worked perfectly well for me countless times. I've even gotten away with using lacquer touchup paint over the Rust Encapsulator, but that's kinda a one-out-of-six situation because the lacquer stuff wants to do a solvent action on the Rust Encapsulator; maybe you'll pull it off, maybe you won't.



For a crappy-looking, but functionally good repair, just use the Rust Encapsulator for the touchup paint and/or top with some enamel like Rustoleum. It'll make the chips look like, well...chips; like they're down to primer or something. But at least the rust will be arrested so it shouldn't get worse. I'd rather have to-the-primer-looking chips than rust any day.
 
Accumulator said:
Then treat the exposed area with a rust converter.
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I suggest you do NOT do this. I just tried rust converter on a large number (50?) of tiny, rusting, rock chips on the leading edge of my hood, and the rust converter discolored the surrounding (white) paint slightly. Rubbing it with alcohol removed some of the stain, but some remained. Since you only have a single chip, you might as well just sand it all the way down to the metal, prime, and paint.



Post treatment my hood looks pretty crappy, but not as bad as it did with all the chips untreated. Before, at a distance there were obvious dark spots all along the leading edge, and these could be seen 20 feet away. Now from that distance it looks fairly good. However, up close each treated spot is a slightly different color than the surrounding paint. It will do for now, but a repaint would definitely have been the way to go for the best results.
 
I've got to keep an eye on this... my ex-gf/roomate/it's-complicated has a spot on her roof with some light rust (i think). Damn rock chips. I just don't want to deal with all the wet sanding and nonsense for a tiny spot on the roof, that might not even have rust.. it might just be the same orange staining junk from the tree...
 
pasadena_commut said:
I suggest you do NOT do this. I just tried rust converter on a large number (50?) of tiny, rusting, rock chips on the leading edge of my hood, and the rust converter discolored the surrounding (white) paint slightly..
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Huh, never had that happen :think: I'm assuming you didn't let the converter overflow out of the chips onto the surrounding paint, right? You *do* need to keep it off paint and only apply it to the area you want to treat. Any contact with paint spells trouble.



Seriously, I've done this countless times, with (IIRC) three different rust converters, and I've never had it do anything except neutralize the rust it came into contact with, except when I slopped it onto surrounding paint and failed to wipe it off right away.



Guess it just goes to show that you need to be careful because YMMV always applies.



The reason I'd always use the converter is that unless you blast there's always a risk of some miniscule amount of residual rust. The old acid-wipes/etc. never killed it 100% IME but the converter almost always does.
 
CocheseUGA said:
Thanks Accumulator. Should I go ahead and get this done this weekend, or will it keep until next?
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As they say, "rust never sleeps", but I don't think one more week is gonna make any big diff. I'd rather do it right (with the right stuff) a week later than do it half-@$$ed right away.
 
Accumulator said:
Huh, never had that happen :think: I'm assuming you didn't let the converter overflow out of the chips onto the surrounding paint, right? You *do* need to keep it off paint and only apply it to the area you want to treat. Any contact with paint spells trouble.
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It did overflow a little. That was pretty much unavoidable since most of these chips were so tiny. (They were probably from sand hitting the hood at highway speeds.) The converter was applied with a toothpick and that was still too large an implement for their size. Only on the two chips which were at least 1/4" across was I able to keep the converter just on the rust.
 
pasadena_commut said:
It did overflow a little. That was pretty much unavoidable since most of these chips were so tiny...Only on the two chips which were at least 1/4" across was I able to keep the converter just on the rust.
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Ah, OK, that explains it then. Yeah, most converters will cause issues on paint (some a lot worse than others, the current Eastwood stuff isn't too bad) and in situations like yours it's a real problem. I gotta admit that when I have a situation like yours I just turn it over to my painter.



Maybe I've just gained some skill over the years, but I'm usually able to keep the stuff in the chip. But then I'm using a magnifying visor and tiny paint brushes for the smaller chips too and I'm usually only fixing ones that aren't too small.



With any luck, the one CocheseUGA is working on will lend itself to no overflow, and at least we've brought up the need to be careful.
 
Wow, that Micromark site has outrageous shipping. Any chance of finding a fiberglass pencil locally? I was hoping to do this this weekend, but I had to put it off until the last minute to find the stuff.



Otherwise, I'm going to try the eraserhead technique with 200, 100 and 2000 grit.
 
CocheseUGA said:
Wow, that Micromark site has outrageous shipping. Any chance of finding a fiberglass pencil locally? I was hoping to do this this weekend, but I had to put it off until the last minute to find the stuff.



Otherwise, I'm going to try the eraserhead technique with 200, 100 and 2000 grit.
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Eh...I never noticed the shipping at MicroMark :o I only use them for stuff I can't find elsewhere and I guess that slipped my mind.



I've never found the fiberglass pencis locally.



Be careful with those really coarse grits of paper, you sure don't want to touch the surrounding paint with them. Anything you touch with coarser-than-2000 grit will probably be beyond fixing given the stuff you're planning to use.
 
to fix a rock chip that has rusted because it knocked away ALL the paint in that tiny area, your gonna need to sand the existing area down, remove a little more paint in that area, and sand the rust out completely before priming and painting again.



you can fix rock chips (tiny ones) if they simply removed clear or base coat and primer is still present, hell you could even put down more base, more clear (with a toothpick) and wet sand it out then buff it and see barely anything.



but if there is rust, i wouldnt risk trying to use a rust converter or simply "trying" to get all the rust with an eraser without removing more paint, rust goes underneath the paint around it, if its been there for more than a month rusting, even a tiny amount of rust left is gonna keep forming under the paint... thats why they call it cancer, get it all or dont bother.
 
Accumulator said:
Eh...I never noticed the shipping at MicroMark :o I only use them for stuff I can't find elsewhere and I guess that slipped my mind.



I've never found the fiberglass pencis locally.



Be careful with those really coarse grits of paper, you sure don't want to touch the surrounding paint with them. Anything you touch with coarser-than-2000 grit will probably be beyond fixing given the stuff you're planning to use.
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Oh yeah, I know. I'll have to be super careful. If I can get it to look like just another chip, I'll be happy. I'm probably going to need a repaint in a couple of years anyway, especially at 30k a year.
 
Turbocress said:
..but if there is rust, i wouldnt risk trying to use a rust converter or simply "trying" to get all the rust with an eraser without removing more paint, rust goes underneath the paint around it, if its been there for more than a month rusting, even a tiny amount of rust left is gonna keep forming under the paint... thats why they call it cancer, get it all or dont bother.
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Eh, not to be all :argue but I've done this *so* many times with great results that I can't agree with you. After *years* of use my previously rusted, touched up chips/etc. have stayed OK.



Some rust converters really are capable of stopping minor rust in its tracks, and Rust Encapsulator is one *VERY* impressive product, not like the old POR-15 stuff that has disappointed so many people.



Latest thoughts- I saw touchup paint (in the Herrington catalog, somebody else has gotta have it...) that's acrylic-enamel. That oughta work *great* over Eastwood's Rust Encapsulator. Rust converter, followed by Rust Encapsulator as the primer, topped with that enamel based touchup paint oughta work fine. It won't have clearcoat, so it won't be a 100% match in every regard, but touch ups seldom are anyhow.
 
Accumulator said:
Eh, not to be all :argue but I've done this *so* many times with great results that I can't agree with you. After *years* of use my previously rusted, touched up chips/etc. have stayed OK.



Some rust converters really are capable of stopping minor rust in its tracks, and Rust Encapsulator is one *VERY* impressive product, not like the old POR-15 stuff that has disappointed so many people.



Latest thoughts- I saw touchup paint (in the Herrington catalog, somebody else has gotta have it...) that's acrylic-enamel. That oughta work *great* over Eastwood's Rust Encapsulator. Rust converter, followed by Rust Encapsulator as the primer, topped with that enamel based touchup paint oughta work fine. It won't have clearcoat, so it won't be a 100% match in every regard, but touch ups seldom are anyhow.
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well, it all depends on how long the rust has been there, but if someone is worried enough to touch it up, chances are they caught it early enough that it didnt spread under the paint adjacent to it being such a small spot.



some rust converters do actually work, and one i found that worked good just to note, is naval jelly. ive used por 15 before, but the stuff seems to work only if you do the most absolute perfect preparation which is near to impossible unless you live and breath cleaning chemicals and live in a perfect environment
 
Turbocress- Yeah, no matter what the method, you do have to get to all the rust. Sometimes that can involve disrupting the surrounding paint, and you sure gotta be careful about how you do that or you'll open a whole new can of worms.



I haven't used Navel Jelly since forever, I bet they've reformulated it a few times since then.



The best rust converter I've ever used was sold by 3M and was called "Rust Avenger". Notice my use of past-tense, they discontinued it :( I have enough to last me a good long time, but so far I haven't found anything quite as good (the current version of Eastwood's stuff isn't *bad* but it's not as good either).



Yeah, POR-15 sure can be finicky. I guess that's part of why I'm so astounded by the Rust Encapsulator; it really works the way the ad-copy for such products says it should. I actually did well with POR-15, never had one problem, but I've known/seen so many cases where other people *did* have problems that I just can't recommend it.
 
Accumulator said:
Turbocress- Yeah, no matter what the method, you do have to get to all the rust. Sometimes that can involve disrupting the surrounding paint, and you sure gotta be careful about how you do that or you'll open a whole new can of worms.



I haven't used Navel Jelly since forever, I bet they've reformulated it a few times since then.



The best rust converter I've ever used was sold by 3M and was called "Rust Avenger". Notice my use of past-tense, they discontinued it :( I have enough to last me a good long time, but so far I haven't found anything quite as good (the current version of Eastwood's stuff isn't *bad* but it's not as good either).



Yeah, POR-15 sure can be finicky. I guess that's part of why I'm so astounded by the Rust Encapsulator; it really works the way the ad-copy for such products says it should. I actually did well with POR-15, never had one problem, but I've known/seen so many cases where other people *did* have problems that I just can't recommend it.
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well, its pretty funny, because it seems that if you skip a single step of the proper preparation of applying por 15, it will flake off in large sheets. ive seen applications of por 15 that you could smack with a sledgehammer and it wont chip, it pretty much bonds with the surface like no other.... but if there is a single molecule of dust, dirt, grease, or oil on the surface, and you dont use their prep solvent or a similar high quality one, and really do a good job cleaning it up beforehand, then its gonna break off in sheets heh.





the naval jelly ive used worked pretty damn well... used a single bottle of it to de-rust almost half of a truck bed, 15-20 minutes of setting on there and you can easily see it change color, doesnt even turn it black. all the auto parts stores carry it, and it worked real well for me when i was doing a restoration.
 
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