Exterior Paint Decontamination Guide Estimated reading: 6 minutes 5980 views Summary: If a wash doesn't remove everything, you may need a stronger, more specific chemical to remove things such as tar, iron, or water spots. Sometimes contamination sticks to paint and can cause damage over time such as etching and eating through clear coat. If a wash doesn’t remove everything, you may need a stronger, more specific chemical to remove things such as tar, iron, or water spots. All of these come before using a clay bar in the detail process. Danger: Hydrofluoric Acid Sometimes it’s tempting to use a harsh, dangerous chemical such as hydrofluoric acid to remove everything, but that’s incredibly dangerous and not advised! Use a specialty chemical for decontamination that is safe to use for detailing, and check your chemicals to be sure they don’t contain hydrofluoric acid. Tar Removers Tar removers are often overlooked chemicals in the decontamination process. They chemically attack anything that is non-polar, which includes most “organic” things you might encounter. Tar removers are great for removing contaminants such as tar, tree sap, glue and adhesives, and other organic residue. Tar Removers are strong solvents, please check the SDS of the product you are working with and wear correct PPE. Also make sure that the product you are using is safe for the materials you are using it on. Most Tar removers are not safe un unpainted plastic and rubber and PPF, if a product IS safe, it will advertise that heavily, so unless the product has a manufacturer release for it, don’t use it anywhere you doubt. Tar removers can make it unviable to be removed from the towel because some can withstand normal washing and sometimes even be a fire hazard if left in the towel. Dispose of used towels safely. To use the tar remover always follow the manufactures recommendation. Make sure to start with washed (if you want to polish after at best strip washed) paint. On paint it is often advisable to spray directly on the paint and then let the product dwell according to manufactures instructions. On more sensitive surfaces it is imperative to be more gentle, often spraying into a towel, wiping and immediately buffing off with a second towel is good practice. The next step is controlling the paint. One step might not have been enough. If residue withstands multiple rounds of tar remover, leave it for claying. In some cases it is advisable to do a second full wash on the car after using the tar remover to make sure all residue is removed. Recommended Tar Removers Gyeon Tar – This is safe on most plastic trim and paint protection film (PPF) if used by manufacturer’s instructions. Optimum T.A.R. – Great for removing tar, adhesives, and rubber. Iron Removers Over time and depending where you park, iron deposits can accumulate on your paint. Often invisible, sometimes visible as orange spots on your paint. If you do notice them it’s time for an Iron decontamination ASAP. Iron removers are very stinky and aggressive chemicals. Take the necessary precautions, read manufacturer instructions and wear correct PPE. For iron removers you want to start with dry paint, as starting on wet paint will unnecessarily dilute the Iron remover and make it less effective. You want to spray the whole car, wait a bit and check where it turns color. Then rinse it off and control in those areas where it changed color. If the contamination is noticeably high or you want to be extra sure you can do a second round. If you need more strength, you can also agitate the Iron Remover with a mitt, I recommend doing that in round two at the earliest. Again, if single spots stay for multiple rounds, you can leave them for claying. It might also be a stone chip that has gone through the paint, so check for that. Recommended Iron Removers P&S Crystal Wash – Acidic and needs to dry onto the surface to work. CarPro Iron-X – It stinks as well as it works – hold your nose and wear a respirator! Sonax Wheel Cleaner Plus – This is usable on paint as well as wheels. It works strongly but doesn’t smell as bad as other iron removers. It’s still not pleasant… Labocosmetica Sidero – This product removes both iron deposits and water spots in one step! Water Spot Removers This is probably the most overlooked aspect of paint decontamination. If you have any kind of mineral residue you should try to remove them as much as possible before polishing. Water spot removers are strongly Acidic Products, please check the SDS of the product you are working with and wear correct PPE. Also make sure that the product you are using is safe for the materials you are using it on. Mineral contamination can also be invisible, especially on matte paint where you cannot polish. This step is a must for coating/sealant preparation, even if there is no visible contamination. After using a water spot remover it is highly likely that you need to do a final wash of the car to remove any residue. Please do not leave them on for unnecessary long and rather do repeat application. Check the manufacturer’s guidance for the product. Recommended Water Spot Removers Labocosmetica Sidero – This product removes both iron deposits and water spots in one step! Gyeon Q2M Water Spot Remover – It’s coating safe, easy to use, and doesn’t contain any sealants. Koch Chemie FSE – This product is great for non-coated cars and comes with a sealant included. Is this safe on my car? The table below is a general guide. Always read the directions, disclaimers, and warnings of whatever product you’re using. Do a test spot to make sure that your product is truly okay for the surface you’re working on. Surface Tar Remover Iron Remover Water Spot Remover Rubber ❌ Unsafe ❌ Unsafe ❌ Unsafe Plastic Varies ✅ Safe ✅ Safe Glass ✅ Safe ✅ Safe Varies PPF Avoid ✅ Safe ✅ Safe Paint (gloss) ✅ Safe ✅ Safe ✅ Safe Paint (matte) Varies ✅ Safe Varies Paint (new) ❌ Unsafe Varies Varies Single stage ✅ Safe ✅ Safe ✅ Safe Need extra help? If you need more detailed help or you have in-depth product usage questions, feel free to hop into the questions forum on the HTAD Discord.