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The Masked Tulip

A Bit Of Rust On Car - Best Option?

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I used some t-cut to rub off a tiny bit of rust on a hatch sill of my car but I have rubbed a bit too much and the paint has actually worn through to the undercoat. The paint must have been very thin there - probably why it had rusted.

It is only a small amount, about half an inch, but I wish to cover it up to give it a bit better protection before the Autumn comes.

What are my options?

1. Do I buy a small tube of the correct paint and dab it over - if so, can I order the correct paint online by giving my reg or something?

2. Or is there some kind of clear lacquer that I could put over it as protection?

3. Or is there something else.

Thanks.

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I used some t-cut to rub off a tiny bit of rust on a hatch sill of my car but I have rubbed a bit too much and the paint has actually worn through to the undercoat. The paint must have been very thin there - probably why it had rusted.

It is only a small amount, about half an inch, but I wish to cover it up to give it a bit better protection before the Autumn comes.

What are my options?

1. Do I buy a small tube of the correct paint and dab it over - if so, can I order the correct paint online by giving my reg or something?

2. Or is there some kind of clear lacquer that I could put over it as protection?

3. Or is there something else.

Thanks.

Assuming its just a small bit of localized rust, you should be able to treat it yourself.

Most car accessory stores like Halfords sell paint touch up kits which are relatively cheap & easy to use (solid colours are easier than metallics). Shouldn't be too difficult to get the correct colour assuming you don't drive anything too esoteric, they are listed by manufacturer. You'll probably need a kit that includes a primer coat & you'll also need some emery paper or similar to remove the rust before retouching the paint.

Paint kits with pens or brush style applicators are easier than sprays from personal experience.

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I used some t-cut to rub off a tiny bit of rust on a hatch sill of my car but I have rubbed a bit too much and the paint has actually worn through to the undercoat. The paint must have been very thin there - probably why it had rusted.

It is only a small amount, about half an inch, but I wish to cover it up to give it a bit better protection before the Autumn comes.

What are my options?

1. Do I buy a small tube of the correct paint and dab it over - if so, can I order the correct paint online by giving my reg or something?

2. Or is there some kind of clear lacquer that I could put over it as protection?

3. Or is there something else.

Thanks.

1 - as above you can buy touch-up pens as well as aerosol spays. Aerosol sprays are not really a good option for the diyer as adhesion can be very poor (the aerosols are propelled mists, the propellant being a solvent that volatilies as it carries through the air, meaning that a good deal of the paint often arrives as droplets with skins that don't adhere to the surface properly). A pad or brush applied coat will always have a better wetting effect that results in better adhesion - albeit at the coost of appearance - not an issue on small patches. The colour should be associated with your reg and make / model. A supplier should be able to help. You don't need to go 'oem'. A generic supplier should be able to help.

2 - clear laquer is just a polymer that has no pigment in it. Pigments don't just colour the coating, they provide protection to the binding polymer from UV degredation. Stick with a paint.

3 - there are other things, none of which strike me as suitable :

- vinyl wraps (for whole body panels only , a good option if you can match, but it's a bit of a specialised skill);

- impressed current galvanic protection (good if you intend to do 007 like trips around the barrier reef);

- scaraficial anodes (again, for permanent submersion).

On a more serious note, make sure you have surface prepped well. Don't be shy about getting the surface there wet. Salts on the surface of metals will draw water through a coating by osmosis given half a chance. It is the adhesion of the film to the metal that opposes the resultant osmotic pressure and keeps the film stuck to the metal. You can reduce this osmotic pressure by removing as much of the road salts as you can. Abrade the rusty bit, but also wash it with clear water (no detergent - it's prolly full of sodium stearate etc). then dry thoroughly with a hairdryer. Also, don't worry per-se about oxidised (rusted) steel. Rust itself will not rust anymore than it has, so it won't try to suck water through the coating you apply, leading to failure. Rust itself is thus not bad - a frequently used indusrial paint uses the pigment micaceous iron oxide - a kind of rust itelf right there in the film. Whay is bad is flakely stff, be it rust or dust or dirt. When a coating cures, huge stresses are created in the film as it grabs the surface. If the surface has flaky rust or dirt or dust, the coating will pop this loose stuff right off, setting up spaces under the film. Not good. Anyhow, that's probably more than you want to know.

Oh, degrease with a solvent like whatever thinners are recommended for your touch-up. And consult on whether you need to prime any bare metal. Some coatings don't, some do.

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I used some t-cut to rub off a tiny bit of rust on a hatch sill of my car but I have rubbed a bit too much and the paint has actually worn through to the undercoat. The paint must have been very thin there - probably why it had rusted.

It is only a small amount, about half an inch, but I wish to cover it up to give it a bit better protection before the Autumn comes.

What are my options?

1. Do I buy a small tube of the correct paint and dab it over - if so, can I order the correct paint online by giving my reg or something?

2. Or is there some kind of clear lacquer that I could put over it as protection?

3. Or is there something else.

Thanks.

1)sand/wet or dry down to the metal

2)coat of primer

3)coat of correct shade paint-actually works better with one shade darker as it will lighten up when properly dry...do on a hot day if possible.proper car factories will bake a coat of paint in the paint shop.

4)coat of lacquer..especially important to get right on metallic paint.

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Have a look at someone like ChipsAway...the trouble is that its difficult to get a perfect match as a DIYer, and the patch may look odd...

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Professionals will do a better job than you with an aerosol.

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Unless you're planning on making car repairs a big hobby then just smooth the rust off with some wire wool then use a colour matched touch up pen type kit and follow instructions. Don't be scared of making the area a little larger when smoothing as getting it perfectly smooth when you apply fresh paint is what will stop people's eyes being drawn to it - ie a rough bump in the paintwork is far more noticeable than a slight colour mismatch.

There might be a paint code on a vin plate on the car somewhere or can usually be obtained from the reg number to get a good match.

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Professionals will do a better job than you with an aerosol.

I can get ok results with a rattle can. You can certainly achieve a repair that's acceptable to most people and compressors and mixing paint to do it properly are a faff. However, you're right you can also easily get some truly awful results.

Paint runs, particularly in clearcoat, are easy to get and the other thing that's a fact of life with aerosols is orange peel finish. Which you can mitigate with a lot of flatting back and abrasive polishing.

Basically you need to pick your battles and employ a few tricks of the trade to get decent results. If you rattle canned the front wing of a car chances are it's going to look awful. If you carefully rattle canned both body coloured wing mirrors or a bit of bumper chances are no-one would notice. If, for example, the lower lip of a boot lid goes rusty one trick is to see if there is a crease/body line going across it nearby. Then masking tape at the body line and spray the entire area below rather than just the area of damage. Then any discrepancy in colour match of finish just looks like it might be the shadow of the light.

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Professionals will do a better job than you with an aerosol.

can't see a pro wanting to fill his wet-spay for 1/2" square. unless he has no work or is looking for experience. either way ...

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Burn it out on some waste ground having reported it stolen. If you claim to have been carjacked by a Somali migrant with 10 kids living in a 5 bed council house, you can sell the story to the Daily Mail*.

*This is not advice and the DM won't pay for your story if you can't prove how much your house is worth.

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Our used Fiat Multi had a cm2 chip down to the primer on the bonnet when we bought it in 2005.

11 years later ...

It looks just the same.

Modern cars don't rust through anymore, AIUI.

Fiats are galvanised. If you go through that to bare metal it will still rust although steel quality in car bodies is generally an awful lot better.

Paint finishes do provide better rust protection but for the cars that are still on the road 15+ years later it's really the galvanising that's keeping them there more than any single other thing providing the engine is reasonably reliable. Vauxhall Corsas and Astras of late nineties vintage were all very well galvanised and although if they had red paint, it's long faded to pink, there's loads on the roads and none of them are peppered with rust.

It also took motor manufacturers a long time to learn the basics of galvanic corrosion. Land Rover were very fond of bolting dissimilar metals together, for many years, like a steel mud flap bracket directly to a thin aluminium body skin which would then subsequently turn to white dust with the addtion of some water and road salt.

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If its just a small spot apparently clear nail varnish is perfectly good to get it through the winter, just make sure its as dry as possible when you do it.

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If its just a small spot apparently clear nail varnish is perfectly good to get it through the winter, just make sure its as dry as possible when you do it.

In anticipation of this, always buy car of a colour available in Boots Economy nail varnish range

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Previously had good results (from a corrosion prevention perspective- the appearance was far from perfect though it is hard to be objective once you know where the repair is and I didn't spend much time getting as close a colour match as possible) by light sanding and then anti rust primer then top coat and lacquer. Maybe an area initially the size of a 20p piece.

Do you know how it is rusting? Eg are the drain channels partially blocked and the hatch is retaining water inside.

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The bottom line is this........

If you can see the rust bubble on the exterior of a panel it's already too late (it has rusted from the inside out)

2 choices:

1. Get a bodyshop to completely cut out the rust back to clean metal and weld up the hole or plate if it is large, grind it flush & respray.

Or my preferred bangernomics method.......

2. Source tge same colour panel from a scrapyard / breakers and just swap them over.

nice and cheap quick fix.

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