Fix tiny rust spot

irlrobins · 31-03-2012 05:20PM #1

Hey all,

Noticed a tiny rust spot on the bonnet of my 06 VW Golf today. Probably caused by a stone chip or other road debris. Chip is prob 5 mm by 2 mm but I'd like to treat it before it got worse.

What's the best approach? Simple touch of matching paint from motor shop?

R

Hal1 · 02-04-2012 01:40PM

A touch up pen will only mask the rust and stonechip. The rust will only spread over time so best to treat it at the early stages.

I would treat the rust firstly. Mask off the area and and loosen the rust with some 800 wet & dry sandpaper. Apply some Krust (small pen size bottle available in halfords). Depending on the depth of the crater it might need some filler. I've used Holts knifing putty and it works very well for small jobs. It goes off in a few minutes.

Wet sand back to a smooth surface with 1200 sandpaper. Then primer, touch up paint (you cars colour), and finally laquer. The results will only be as good as your prep work.

fasttalkerchat · 04-04-2012 12:23AM

Hal1 wrote: »

A touch up pen will only mask the rust and stonechip. The rust will only spread over time so best to treat it at the early stages.

I would treat the rust firstly. Mask off the area and and loosen the rust with some 800 wet & dry sandpaper. Apply some Krust (small pen size bottle available in halfords). Depending on the depth of the crater it might need some filler. I've used Holts knifing putty and it works very well for small jobs. It goes off in a few minutes.

Wet sand back to a smooth surface with 1200 sandpaper. Then primer, touch up paint (you cars colour), and finally laquer. The results will only be as good as your prep work.

This, plus sand after each layer of primer and each layer of paint. You want to get at least 3 of each... weather permitting.

String · 04-04-2012 10:33AM

If its just a tiny rust sport wouldn't scratching the rust away and then dabbing it with some sort of rust treatment to chemically change it be enough?

irlrobins · 04-04-2012 03:23PM

I was about to ask the same. Call me lazy but that seems a lot of work for a rust spot that so small.

fasttalkerchat · 04-04-2012 03:37PM

irlrobins wrote: »

I was about to ask the same. Call me lazy but that seems a lot of work for a rust spot that so small.

For an 06 Golf i think its worthwhile.
Up to the OP really. If you paint over it you will have no problems for a year or so.

Hal1 · 04-04-2012 03:51PM

Sure there are plenty of stone chip kits you can buy that would mask the chip, but ideally you would want to treat the rust. The guide I wrote above would ensure the rust would not return.

dharn · 04-04-2012 07:01PM

i would expect 90 % of people who tried the above job for a stone chip would probably make it look worse ( sand, prime, sand again paint , lacquer )

fasttalkerchat · 04-04-2012 08:18PM

dharn wrote: »

i would expect 90 % of people who tried the above job for a stone chip would probably make it look worse ( sand, prime, sand again paint , lacquer )

I thought it was quite simple. just put some tape arounf the patch so you dont damage surrounding paintwork. I was impressed with the result from the halfords 3 pen set.

irlrobins · 05-04-2012 10:52AM

dharn wrote: »

i would expect 90 % of people who tried the above job for a stone chip would probably make it look worse ( sand, prime, sand again paint , lacquer )

Yeah, that's my fear. I'd rather pay someone to do it right first time.

dharn · 05-04-2012 07:04PM

the point i was making was that for the average stone chip, size of match head or less ,touch in pen should be fine , some guy was talking about sanding,priming,paining, laqureing, that sounded like a bad idea to me

Owen · 05-04-2012 07:55PM

Not to mention the terrible idea of putting tape around the repair area *shudder*

Hal1 · 05-04-2012 11:20PM

What's the problem with using tape to prevent overspray? It should be ok once you give light pases between each coat. It won't leave an outline then.

fasttalkerchat · 06-04-2012 01:50AM

Owen wrote: »

Not to mention the terrible idea of putting tape around the repair area *shudder*

?? How would you do it?

GaryIrv93 · 06-04-2012 01:53AM

http://www.howtogetridofstuff.com/household/how-to-get-rid-of-car-rust-spots/

challengemaster · 06-04-2012 06:25AM

Hal1 wrote: »

What's the problem with using tape to prevent overspray? It should be ok once you give light pases between each coat. It won't leave an outline then.

The problem is you wouldn't be spraying anything in the first place, you're only making work for yourself with such a small area. Very fine brush and building up layers, same as you would for a regular stone chip just with some more prep to get rid of the rust.

dharn · 06-04-2012 11:15AM

Hal1 wrote: »

What's the problem with using tape to prevent overspray? It should be ok once you give light pases between each coat. It won't leave an outline then.

why would you spray a stone chip ???

Owen · 06-04-2012 11:33AM

Hal1 wrote: »

What's the problem with using tape to prevent overspray? It should be ok once you give light pases between each coat. It won't leave an outline then.

Tape will give you a hard defined edge. I'm in the middle of repainting a bumper someone had a go of themselves using that sort of advice, you can clearly see the parallelogram of the new paint where the owner taped off the repair area. I now have much more work to correct what would have originally been a simple repair.

You don't spray stone chips/small rust spots. There is no quick fix. You either respray the panel in its entirety, or you use a cosmetic fix like a paint pen. The paint pen won't fix the rust, or the crater around the paint, just put colour on it, it'll still be visible from a meter away. The day someone comes up with a solution for stone chips that actually works they'll make their fortune.

Hal1 · 06-04-2012 12:22PM

dharn wrote: »

why would you spray a stone chip ???

A touch up pen would be better in this situation for a stone chip. Rust spreads, I was just suggesting a method to prevent it from bubbling back . Although after reading Owen's post I can see how my method is flawed. Thanks

.

fasttalkerchat · 06-04-2012 12:30PM

Owen wrote: »

Tape will give you a hard defined edge. I'm in the middle of repainting a bumper someone had a go of themselves using that sort of advice, you can clearly see the parallelogram of the new paint where the owner taped off the repair area. I now have much more work to correct what would have originally been a simple repair.

You don't spray stone chips/small rust spots. There is no quick fix. You either respray the panel in its entirety, or you use a cosmetic fix like a paint pen. The paint pen won't fix the rust, or the crater around the paint, just put colour on it, it'll still be visible from a meter away. The day someone comes up with a solution for stone chips that actually works they'll make their fortune.

Ah okay I see now, the tape is for when you are sanding so you don't scratch the surrounding paintwork. Don't spray either.

Owen · 06-04-2012 12:38PM

No tape, no sanding. Just don't go at it. It'll end up a mess, even I wouldn't do it. Either spray the whole bonnet, or don't go at it.

fasttalkerchat · 06-04-2012 12:49PM

Owen wrote: »

No tape, no sanding. Just don't go at it. It'll end up a mess, even I wouldn't do it. Either spray the whole bonnet, or don't go at it.

Each to their own but his chip is 5 mm by 2 mm. Thats too big to leave because it was rust and flake. I had a bigger one and i spent a week sanding and using the halfords 3 pen set and did a perfect job. If it doesn't work out you could respray after.

Maybe I'm too much of a perfectionist.

Owen · 06-04-2012 02:29PM

In all my time here I've seen bad advice given out and I've tried to disuade people from having a go when clearly they've never practised on scrap panels to build their skill level, or if they're listening to 20 different people with 20 different approaches - this shows they clearly don't have the skill level. Some people refuse the advice, and decide to have a go themselves promising photos of the job when it's done after.

In all my time here (Apart from Alloys) I've never seen anyone put up a photo of the bodywork they've done themselves. And I'd be 99% certain that it's as a result of making a monumental f*ckup and having to pay someone to do the job making it more expensive & time consuming than just getting it done the right way the first time.

irlrobins · 06-04-2012 10:52PM

Like I said, I'm happy to pay someone to get it right first time than me making a pig ears of it. I had thought of just touching it up but as some people had pointed out I'd probably just be hiding the damage and the rust could still spread under it.

dahamsta · 06-04-2012 11:18PM

Owen, do you have a particular procedure for doing stone chips? I have an OEM BMW kit that wasn't cheap, but it's sat on my hall table since I got it because any time I've gone looking for howtos I've come across horribly complicated procedures like the above. Is it really just a case of dab it on as carefully as you can, and deal with the rust when it actually becomes an issue?

challengemaster · 06-04-2012 11:28PM

dahamsta wrote: »

Owen, do you have a particular procedure for doing stone chips? I have an OEM BMW kit that wasn't cheap, but it's sat on my hall table since I got it because any time I've gone looking for howtos I've come across horribly complicated procedures like the above. Is it really just a case of dab it on as carefully as you can, and deal with the rust when it actually becomes an issue?

If there's rust there it already is an issue, just not a major one. If you cover over it and leave it to spread, all you'll end up doing down the line is having to cut out a large piece of metal and weld in a replacement. Covering over it is only stopping you from seeing the damage

06-04-2012 11:31PM

fasttalkerchat wrote: »

Each to their own but his chip is 5 mm by 2 mm. Thats too big to leave because it was rust and flake. I had a bigger one and i spent a week sanding and using the halfords 3 pen set and did a perfect job. If it doesn't work out you could respray after..........

Perfect with a Halfords 3 pen set? I find that very hard to believe.

trixyben · 06-04-2012 11:49PM

is there a treatment or what is the best treatment to get rid of the rust?

I have a small chip above rear whell arch thats going to need attention soon

Owen · 07-04-2012 08:46AM

dahamsta wrote: »

Owen, do you have a particular procedure for doing stone chips? I have an OEM BMW kit that wasn't cheap, but it's sat on my hall table since I got it because any time I've gone looking for howtos I've come across horribly complicated procedures like the above. Is it really just a case of dab it on as carefully as you can, and deal with the rust when it actually becomes an issue?

Pretty much unfortunately. There is one system which sort of half works, Sprayless Scratch Repair but it's not a long term solution. It's a resin which is mixed up to match the pigmentation of the paint on the car, smeared in to the chips so there's a bit too much, then machine polished flat.

It's still a visible repair as nothing can remove the circular outline of the stone chip, and in time power washers will remove it, but it does a reasonably good job of masking the damage. It's not something I do BTW before you ask

dahamsta · 07-04-2012 09:11AM

That's what I thought, and it doesn't bother me. Sure who has the time and money to fix every little chip as it happens! Thanks Owen.

kevin65 · 07-04-2012 10:45AM

No need for drama with small rust spots. Just use a small craft knife with a sharp point to carefully remove loose pieces of paint and rust. If spot is very small, use the knife to carefully scratch out the remaining rust. If you go using sandpaper, you need to be careful or you end up damaging the srroundng surface. With all rust and loos paint removed, clean the surface. You could use a little bit of warm water and wash up liquid, wiping with a squeezed out cloth, rinse the cloth and then wipe again. If you have something like IPA, just give it a quick wipe. Give the spot a coat of rust primer paint with a small artists brush, making sure you only paint the surface of the spot. This should dry to be slightly below level of surrounding paint. Follow up with top coat and lacquer, the touch up kits from the manufacturer will give you the best match. Leave for a couple of weeks for paint to fully cure and then use some 2000 grit wet and dry to lightly sand the spot followed with some scratch removal polish and then a good coat of wax.
It will never be invisible when you look along the surface, but much better than rust!

Fix tiny rust spot

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