Removing da swirl marks

[crispyj]

Hi.

I had my bonnet painted 6 years ago and I would like to improve the finish. You can see da marks in it caused when the paint was denibbed.

When the car is polished with srp you don’t notice them but after a wash they return. What’s a good solution for removing them totally.

Thanks.

[paddy328]

The bonnet needs to be properly machine polished

[Paul_M3]

If you buy a Dual Action polisher yourself (such as a DAS-6 Pro) you can achieve some very good results as an amateur.

My R8 was terrible, like it had been washed with a broom all it's life. These shots in direct summer sunlight show it well.

Here's the bonnet before I started:



And he's the shot after I'd done half of it:

[crispyj]

What compound did you use.

[Paul_M3]

crispyj said:

What compound did you use.

To be honest, I can’t remember what one I used for that particular job.

I think it may have been Meguiars Ultimate Compound.

That has good correcting power but also breaks down leaves a fine finish that doesn’t necessarily need a finishing stage.

[SeeFive]

crispyj said:

What compound did you use.

If only there was a silver bullet

The first question would be, what paint have you got? Single stage, clear over base? What make of car is it as makes use different hardness of paint? What colour is it, for example flat blacks tend to need a lot of thought about refinement after cut depending on the make/paint. All paints respond differently to correction techniques, especially those that have had work but the good news is there should be plenty on there if it has been repainted - decent painters tent to lay it on a bit thicker than robots at the factory. Also, anything that has had paint is likely to respond different to the factory paint. If it is a local smart repair, be very careful, they tend to use soft paints.

Would really need to see the paint and type of imperfections to make a judgement on the approach and then judge how that responds - is it really damage put in by denibbing or just bad use of a mop - which is more usual IME.

The general rule is to test it and go as light as you can to remove the damage as far as you would like without removing too much paint - it is not always possible to remove everything but if you go too heavy with the compound first off, you can’t put the paint back on in order to give more latitude for corrections in future years. It is unlikely that a DA will take you through the paint unless you are chasing deep scratches blindly with heavy compounds - that is something you need to judge for yourself on the job.

Personally, for swirls and buffer trails with a safer style polish that breaks down and refines as you go, my go to is Megs 205 on an orange hexlogic pad which is quite a light polish on a medium cut pad and 4 slow passes with a DA is typically enough to allow the polish time to do its job depending on lots of things - most relevant right now is probably air temperature. If that doesn’t get me where I want to be straight away, then I go again on the test patch with Megs 105 to see what happens and refine with something like (see later) 205 after.

In terms of cut, 105 on orange hexlogic should take out the type of scratches that you would see from 1500 grit paper fairly easily, so it is still a lightish polish rather than a full on compound. We are talking about removing a few microns here, so no deep scratches. If they are very deep straight scratches, and having no paint depth gauge, I tend to try to improve them locally by hand if they look too deep to get right out safely before refining.

More recently I have got more into the ceramic polishes and LSPs, and refine after cut with Turtle Wax Hybrid Ceramic polish to refine and start the ceramic protection layers. That is even less aggressive than Megs 205 so I wouldn’t recommend starting with that as for what you describe as you will probably be there for weeks.

[Summit_Detailing]

Alternatively, instead of spending the money on a polisher, pads, polish etc, which you may use again (but probably not) you could find a detailer local to you who I'm sure would be more than happy to buzz over the bonnet for you, quite possibly for less than the aforementioned equipment.

Cheers,

Chris

[Paul_M3]

Another cheap option could be to join the Detailingworld forum.

Those guys are crazy about stuff like that.

I bet if you put a post on there about it somebody local would happily come show you what they could do for a token gesture of a few quid. (Just try and get a feel for if it's somebody who has a rough idea what they're doing first!)

[Blue62]

Summit_Detailing said:

Alternatively, instead of spending the money on a polisher, pads, polish etc, which you may use again (but probably not) you could find a detailer local to you who I'm sure would be more than happy to buzz over the bonnet for you, quite possibly for less than the aforementioned equipment.

Cheers,

Chris

Very good advice, a pro will always do a better job and though I’ve had reasonable results in the past the stress free route is to trust it to someone who does it for a living.

[SeeFive]

Blue62 said:

Summit_Detailing said:

Alternatively, instead of spending the money on a polisher, pads, polish etc, which you may use again (but probably not) you could find a detailer local to you who I'm sure would be more than happy to buzz over the bonnet for you, quite possibly for less than the aforementioned equipment.

Cheers,

Chris

Very good advice, a pro will always do a better job and though I’ve had reasonable results in the past the stress free route is to trust it to someone who does it for a living.

... and of course you won’t get all your relatives asking you to spend 2 days each paint correcting their car every year as they wash it in between with kitchen scourers or give it to the abandoned petrol garage car scratchers.

My little DA has done all that for the last 10 years or so, plus the real monster... the oxidisation on the boat for the last few years. But it struggles on, I changed the brushes this year for the spare ones that were shipped with it but have spent a fortune on different polishes and pads over that time.

[crispyj]

Thanks for the info. The car is a aston db9 but it has been repainted so not original paint. It’s clear over base and a dark blue colour.

[V8covin]

The marks you describe won't be from using a DA polisher, they'll be from a rotary.A DA polisher needs to be used now....... that's assuming the marks you can see aren't under the paint