Randy C.

I did a search on past post regarding brightening concrete, but do not feel that they advised me the best solution to my problem. I cleaned a driveway this morning using a 20" surface cleaning and hotwater. The drive way mostly had pine sap and dirt on it, with a few light rust spots. I applied Sodium Hydroxide in the dirtiest areas prior to cleaning. Then after using the surface cleaner I applied sodium Hypochlorite to spot clean some areas that weren't coming clean. I then rinsed the area after allowing it to dwell for approximately 10 minutes. I went back this afternoon to check on the driveway. I now have approximately eight exteremly white spots ranging from 4 to 10 inches in diameter (from the sodium hypochlorite). The driveway is 16' X 80' and the the spots stick out very badly. Note: Their are also still a couple of minor rust spots still showing. My Question is can I effectively blend the spots by attempting to brighten the whole driveway, giving it a professional appearance or just let the driveway stay the way it is? I want to fix my mistake and produce the professional results I promised, but don't want to cause more damage to a already bad situation. I understand there are basically two methods of doing this sodium hypochlorite and oxalic acid, which will yield the best results, or should I use them both? If I use the Oxalic Acid it is my understanding that the common mix is 2-4 pounds/ 5 gallons. And if I use 12.5% sodium hypochlorite should I shoot it straight? Also how long should I allow them to dwell before rinsing? Or should I just apply the chemical and leave it on? Thanks in advance for all you help, Randy

Well, when you are a rookie (which I am) you spend all you time reading the post that experts such as yourself have posted. I have learned so much over the past year of reading old post. I thank you and everyone else for sharing your experience and knowledge. I am sure over time I will post more often. Again thank you all, Randy

UPDATE: GOOD NEWS I went back over to see the driveway today to take pictures of the spots and talk with the owner. Much to my relief I found out that the spots were already there! It wasn't caused by anything I did or didn't do. As I began to explain to the owner that somehow I managed to screw up his driveway, and apologized about how badly the white spots looked. He began to laugh and told me that he had forgotten to tell me about those spots. He informed me that they have been there for over a year, but since the driveway has gotten dirty they didn't standout very bad before I cleaned it, and said that my work looked great, which makes the spots really stand out. He advised me that the bright white spots were caused by a product that his kids had been using to clean their tires & rims. He thought it was some type of wax or something. When I looked at the spots it appears to me that the concrete has been extremely whitened, possibly by some type of acid based product and not a wax as he suggested. He wanted me to see if I can figure out how to remove the spots. So here is my new question to anyone with any advise: 1. What do you think happened to cause those spots? 2. Do you think the spots can be removed or will he just have to live with a spotted driveway? 3. And if you think they can be what method would you suggest? I have attach some picture of the driveway, both before and after. If you look closely at the before pics you can see the spots are already there. I also included a couple pics of the spots. Thank God I took before pics and was able to see that the spots were indeed already there prior to my cleaning the driveway! Please give me your opinion on this matter, Randy A. Crandall Skyline Exterior Cleaning Hamptonroads, Virginia