magic acid bath

[popsinc]

has anyone tried this? I did this morning on my red 2005 Audi S4 and it did nothing. I believe that the old water spots had etched the paint on the hood roof and trunk. Also, I have tried a few good products, clay bars, polishes etc. Any ideas on what I should do next? I have vesited a few web sites that recommend having a pro buff out the car when all else fails.

[Brian_Brice]

You should probably have a pro look at it for you. Audi`s are traditionally very hard clear coats, one should know what he`s doing in tackling that kind of issue.

[popsinc]

in your opinion, would you even try using a compound? I have an old friend who owns a body shop that Im sure he can halp me out. However, hes a bit away from where I live.

[Brian_Brice]

In my opinion I wouldn`t hesitate to using a compound, with your paint I wouldn`t hesitate to use the mother of all aggressive compounds :lol. Also remember most body shops are body straighteners, not necc. beautifiers, and by no means pro detailers.

[Accumulator]

FWIW A few years ago Accumulatorette got some water etching on her `00 A8 and my remedial efforts were not successful :(



I got pretty aggressive with the rotary and nope, I`d have to try wetsanding next. I talked it over with her and she said she`d rather have thick clearcoat so we`re just living with it.



I`m a pretty big fan of AutoInt/ValueGuard`s "ABC" system, but such stuff only seems effective with regard to keeping the damage from getting worse; once the etching happens the paint is etched, simple as that, and the only thing that`ll correct the pitting is abrasively leveling the clear down to the level of the bottom of the pits.



So I`d give some thought to how much clear you`d have to lose and how you feel about that. I`d also be pretty careful about who you let do the work if you decide to have it corrected by someone else.

[imported_DetailDan]

Also remember most body shops are body straighteners, not necc. beautifiers, and by no means pro detailers.



:2thumbs: got that right!

[popsinc]

I have used Griots machine polish 1-4 and the swirls disappeared. But the etching/spots did not. What would be a good yet safe compound? 3M perfect it?

[Accumulator]

I have used Griots machine polish 1-4 and the swirls disappeared. But the etching/spots did not. What would be a good yet safe compound? 3M perfect it?



First, congrats on getting the other marring out with the Griot`s MPs...they never worked all that well for me by PC (better by Cyclo).



Assuming you`re working by PC/etc. (as opposed to rotary), I`d probably go with Hi-Temp Extreme Cut instead of the 3M. I really (*REALLY*) like the old 3M PI-III RC 05933, but it`s getting hard to find and the H-T EC probably has more cut anyhow.



But again, such products (3M PI-III Extra Cut 05936, some seriously aggressive stuff) used with a cutting pad on the rotary (and at high speeds too) weren`t enough to remove the etching on our A8. Made it better, but not that much.



Use a 4" pad, I wouldn`t even bother trying with a larger pad (by PC). Just have realistic expectations and be prepared to consider wetsanding if you *really* want to get the etching out. Yeah, IME a PC/4" combo can remove3-4K sanding scratches from Audi clear if you work at it. But that wasn`t a route my wife and I wanted to take on a car that actually gets used....thin the clear too much and you can`t do any subsequent correction without precipitating failure.



This reminds me of my `91 Porsche C4...nasty waterspot etching that I never did sort out. Porsche offered to repaint the car but I never took them up on it for fear it`d turn out awful.

[popsinc]

thanks for the help! I`ll keep ya posted on what I come up with!

[Accumulator]

thanks for the help! I`ll keep ya posted on what I come up with!



Good! Maybe you`ll get lucky and the etching won`t be too deep. It`d be great if you could get it out without taking off a scad of clear. Never know until you try!

[Saintlysins]

In my old school days, (1978 to 84) and the shop I first got my guppy-gills wet doing body work, we would use wool pads on 5000+ rpm grinders that weighed 15 lbs or more, that we’d convert to buffers, using heavy compounds and slow steady motions, we were able to build up enough heat that the surface of the clear-coat would ‘almost/kind-of/sorta/if-you-know-what-I-mean’ seem to melt just enough to resurface and loose those etch marks. I went into all that for this next part:

As “Accumulator� expresses, be careful with the clear coat, so here’s a very rare moment that worked out well. Was I lucky ... maybe ... but here’s what we did:

We had a client with the same dilemma you have (2003 Merc S Class) who wanted a bad case of those etchings out. I looked up a guy I know who still does old-school restoration and painting for antiques and collectables in the same shop I started in. He’s still using these old techniques to match the finish for the period of time the cars were made. Making this a shop trip, took the whole crew up to his shop with the car ... and he went to work. With some old school techniques, wool pads, cotton string-tie bonnets using black ebony ... he got 95% of them out. Every one of the guys I brought up was astounded by the results. After he was done we went over the car with Sonus Step 2, polish, glaze and wax. The clear is still on the car and the customer is dazzled!

I’m not saying I’d do this as a regular practice. In fact, if it wasn’t for the client and the relationship we have with him, I’d never have tried this! But if you’re desperate, and you can find a shop ... and a senior member of the shop who still has the ability to ‘read the feel of wool-pad-drag’ those old wool pads feed back on an old school rotary ... maybe, and with luck ... you may get the results you’re looking for. I know I don’t have that touch anymore.

If you’ve decided to repaint ... then at least try this technique on a panel first and see if it will give you what you’re looking for.

Hope it helps.

[Accumulator]

Saintlysins- Similar experiences here...including that I too started out working with a mighty crude single/high speed rotary system in `78. Worked well on single stage, at least for me but I wouldn`t have wanted to try it on b/c.



Also, I`ve seen that "melt the clear"; sure amazed me! Wouldn`t have believed it had I not been there. *BUT* the guy who did it wouldn`t try it on a nasty RIDS (Random Deep Isolated Scratch, from a rock) on the S8`s trunk lid; heh heh, he wasn`t willing to risk *my* displeasure and that told me that it`s a mighty iffy thing even for the guys who can (usually) do it.

[Saintlysins]

Yeah, I took a risk, but this guy is a real pro and his experience and technique is almost Zen like and I trust him to know when to say NO. He trained me (felt more like mental abuse, torture and ridicule :sadpace: ), back in the day and he`s only gotten better with age and technique. But I had great arms and shouders from that friggin` 15 lb grinding monster after a few months of getting the technique down. Too bad I don`t have that skill anymore

Those days sucked while I lived in them :bawling: ... but now they`re the `good `ol days` :bigups .

[wannafbody]

I started using a Craftsman grinder/rotary that weighed 14#. These kids today just have it

too good. These new lightweight orbitals and rotaries have them spoiled;)

[popsinc]

I am going to see my body man tomorrow and will ask him for his opinion. I do agree that body shops are not pro-detailers. However, this guy has done body work on all of my families cars in the past and has won numerous awards on building custom cars and etc. I`ll see what he has to say. But the more I hear it, I think i will end up using Meg #9 followed up by Meg #26 and call it a day with my Griot`s D/A polisher. I have used these products before on my other cars and have recieved great results and are easy to work with. Its funny, I say all of this now, but when I look at my hood at an angle, and those dam spots keep showing up, who knows what I`ll do!!!