3 Autos - Concrete Removal from Paint :/

[Bates Detailing]

Hey all - we have 3 scheduled jobs this week that include concrete removal from paint. I was going to try the vinegar/water method - but was curious if anyone here had any better ideas?!?!? Tomorrow includes a brand new black Caddy with lite cement splatter - the next 2 are on friday with heavy splatter. What will it take to get these safely removed?!?!? Also, will these spots require some heavy cutting due to scratching of the removal process? Any ideas would be appreciated - Thanks,

Anthony

[CM8 6MT]

Hey all - we have 3 scheduled jobs this week that include concrete removal from paint. I was going to try the vinegar/water method - but was curious if anyone here had any better ideas?!?!? Tomorrow includes a brand new black Caddy with lite cement splatter - the next 2 are on friday with heavy splatter. What will it take to get these safely removed?!?!? Also, will these spots require some heavy cutting due to scratching of the removal process? Any ideas would be appreciated - Thanks,

Anthony

Ive used that method before with great results. However, on some "tough" spots, I used an old eye drop bottle with straight vinegar so im able to get it as much on the cement only as possible. Worked great with no harm to the paint.

[Bates Detailing]

Ive used that method before with great results. However, on some "tough" spots, I used an old eye drop bottle with straight vinegar so im able to get it as much on the cement only as possible. Worked great with no harm to the paint.

Awesome - thank you! Great idea

[ProDetail]

Hey Anthony, I saw this thread a while back and it also includes some advice and tips from Mike. Hope it helps. Concrete Overspray

[Aaryn NZ]

Hey mate, I'm not sure if this is going to be much help to you at all but down here in New Zealand we can get stuff called Ecocrete. I have some that I get from a local concrete supply shop & it works really well. It's a liquid that you spray on to concrete splatter & it dissolves it. Totally safe on any auto parts. Works best sprayed on to completely dry surface & left over night but I'm guessing you don't have that luxury time wise. Maybe try calling a concrete supply store over there, possible they may have something to help you out.

[PiPUK]

Concrete removal is tough. The problem is that 99% of soils you encounter will be acidic in nature, as a result the vast majority of cleaning products of cleaning products are alkaline. Cement/concrete is the opposite, it is quite strongly alkaline/basic in nature so normal cleaning products have little effect - you need an acid. Unfortunately, acids tend to be unfriendly to paint work.

Hydrochloric/Muriatic acid is often known as brick cleaner and is a cheap and extremely effective way of removing stains like this. However, this is one nasty acid and I would never consider it safe for use on paint.

Phosphoric acid is a whole lot safer and is often what you find in safe or mild acid based wheel cleaners. It will not be as effective but it will still be really very good. I might use this on paint if forced but, again, I wouldn't if I could avoid it.

You then have weaker acids like oxalic, acetic, lactic or citric acids. The latter two are pretty safe, they find application in things like chemical skin peels so I would probably have those as my go to acids here. Oxalic is used in cheap fallout removers but it should still be used with care. For example of use see this Toyota guide. Make careful note with regards to the baking soda step, this is important for the long term health of the paint, even if many in the UK are ignorant of that fact.

As a final suggestion, you could try the finishkare paint cleaning system. I don't know what acid is in this but it claims to be safer than oxalic and, more importantly, finishkare are expert enough to have included the important neutraliser.

Whatever you do, make sure you neutralise when done (baking powder or most APCs will do it). Although you are unlikely to see damage as soon as you apply, acidic residues can do harm at a level invisible to the eye and can manifest months or even years in the future. Whilst cheap and nasty valeters can ignore this and realise that damage will be impossible to be blamed on them, as detailers I am sure we will all agree that we should work to the highest standard.

All the best.

[tuscarora dave]

Muriatic acid/water mixture works well to remove the concrete splatter, but as mentioned above it's not all that good for the paint if left to dwell for long periods of time. Any cleaner degreaser that uses caustic soda as an active ingredient (look at MSDS) such as "Purple Power" or "3D international Orange Degreaser" will neutralize any acidic residual left behind. I get the concrete splatter (sometimes pretty heavy) quite often on the wheelchair vans that I recon for resale. A gallon of muriatic acid is about $5 at your local hardware store. I start with a 1:5 dilution ratio, that is 1 part muriatic acid to 5 parts water which works well for light splatter. If the concrete is caked on pretty heavy I'll up the concentration as needed. I spray it on the concrete and use a soft horsehair parts cleaning brush to agitate the mixture and help in the dissolving process. Spray...agitate...spray...agitate etc. etc. This method doesn't scratch the paint all that much but usually some correction afterward is necessary.

The steps I take are as follows...

pre-spray vehicle with pressure washer to remove any light or loose concrete splatter.

working in one manageable sized area at a time, spray the muriatic acid/water mixture onto the effected area and allow to dwell for a minute or 2. (trust me when I say that this mixture will not boil the paint off of the vehicle..no need to be hysterical here..)

After a min. or 2 of dwell time, respray area with acid mixture and also wet your cleaning brush with acid mixture and begin brushing the concrete off of the section you're working on. The splatter typically brushes right off if it's not too heavy. If it doesn't brush right off...re-spray and re-brush.. repeat as many times as necessary.

After the removal is achieved.... pressure rinse the vehicle thoroughly being careful not to spray the acid mixture back onto yourself. Start rinsing from like 4 feet away to avoid spray back and work your way closer to the vehicle as the acid is being diluted by the rinse water. Acid doesn't rinse off that easily so really rinse it for a while.

After rinsing the vehicle, spray the vehicle down heavily with a 50/50 dilution of caustic cleaner/degreaser (I use a garden sprayer for this) ensuring that you are getting the degreaser down behind any trim pieces or cracks where the acid may have gone. You have now neutralized any residual acid that may have been present. Re-rinse the vehicle and proceed to your normal washing/claying/polishing/waxing
routine.

A few things to consider...

Safety first... this acid is nasty stuff... there will be smoke like vapor coming out of the acid container when you first open it up...ALWAYS wear gloves, safety goggles, and long sleeves when working with this stuff.

Don't take chances when decanting this stuff...ALWAYS have a funnel to work with during the diluting process...

DO NOT spray muriatic acid on raw/uncoated aluminum. It will etch it immediately!!! Avoid spraying on aluminum brake calipers and associated hardware. Cast iron will be unaffected.

NEVER perform the above procedures where a dog or other pets are likely to be lapping up your rinse water off of the ground.

NEVER perform the above procedures in windy conditions.

ALWAYS remember that acid doesn't rinse easily... They say flush with water for 15 minutes for a reason. You can't spray caustic degreaser in your eyes to neutralize acid so eye protection is a MUST!!! You can use caustic degreaser to neutralize acid spills on the ground or on your hands or wrists but the caustic itself will do a number on your skin so a sodium bicarbonate wash (baking soda/water) should be handy for any skin/acid neutralization needs.

Upon asking one of my most respected detailing mentors what processes work best..... he always asks me..."Do you want to know the most effective way or do you want to know the sissy way?" Trust me when I say that the above described methods are not the sissy way, and safety should be at the forefront of measures. It's been shown that muriatic acid spills on skin (not sufficiently rinsed/neutralized/rinsed) can cause severe skin burns upon waking up the next day. The sodium bicarbonate wash is not to be dismissed as trivial.

Hope this helps...TD

[steamshooter]

Always add acid to the water, not the other way around. If you add water to acid it could erupt and get on you.

[Mike lambert]

Find a malco distributer and ask them, I forgot the name, maybe the graffiti remover, but it works very well.

[PiPUK]

Muriatic acid/water mixture works well to remove the concrete splatter, but as mentioned above it's not all that good for the paint if left to dwell for long periods of time. Any cleaner degreaser that uses caustic soda as an active ingredient (look at MSDS) such as "Purple Power" or "3D international Orange Degreaser" will neutralize any acidic residual left behind. I get the concrete splatter (sometimes pretty heavy) quite often on the wheelchair vans that I recon for resale. A gallon of muriatic acid is about $5 at your local hardware store. I start with a 1:5 dilution ratio, that is 1 part muriatic acid to 5 parts water which works well for light splatter.

I would honestly recommend against Muriatic acid for everything but caked on concrete (which I accept will sometimes occur). It will react even with iron and steel and you will end up with corrosion, even with short contact times. This is the reason, you should not just use the acid and should use formulated products when cleaning wheels (pretty much the only place it is used on any scale) - muriatic acid itself has nothing which inhibits corrosion, nothing to protect whilst in contact and nothing to protect after it is removed. Formulated products will typically have corrosion inhibitors which will passify metal surfaces whilst treating and stop the almost inevitable oxidation and rusting subsequently. Beyond that, if the muriatic acid you get is indeed industrial strength then that 1:5 dilution will have a negative pH such will be it's strength (don't try measuring it, most pH meters are totally inaccurate below pH of 1) - I really really would not recommend the use of this acid other than on industrial vehicles.

Another note with regards to the caustic neutraliser - again I feel that this is something that should be treated with care. Sodium hydroxide is the basic equivalent, if you will, of HCl. In other words it is another sledgehammer and at significant odds to Mike's mantra of using the least aggressive chemical neccessary - NaOH is pretty much the most aggressive you will find. Again, fine for use on industrial type vehicles but totally un-necessary for private vehicles. NaOH is known to cause etching of paint so whilst not excessively dangerous at low concentrations (low means less than 0.1% - which likely still has pH approx 13), high end users would be better using something with a silica based source of alkalinity (as a general rule for detailers) which is equally capable on almost every application except heavy duty degreasing.