platosgal Posted January 3, 2015 Posted January 3, 2015 Hi all! I am working on polishing a concrete slab. The existing slab has recent sulfuric acid stains and areas where the chemical is in high concentration. We need to clean this off the concrete completly in order to apply acrylic I need to know the safest method to do this. I have been told,use baking soda and water? This seems wrong!! Any help would be so great Thanks
studiot Posted January 3, 2015 Posted January 3, 2015 Why can't you just polish the stain out? The concrete will have neutralised any acid. Have you a photo?
platosgal Posted January 4, 2015 Author Posted January 4, 2015 it is in a facility where on of the rooms has large containers that leak..so the acid is very fresh and when they move the containers that leak we only have a few hours to clean and treat the concrete
StringJunky Posted January 4, 2015 Posted January 4, 2015 It seems you were given ok advice and the reaction products are safe; sodium sulphate, carbon dioxide.and water.
Sensei Posted January 4, 2015 Posted January 4, 2015 It seems you were given ok advice and the reaction products are safe; sodium sulphate, carbon dioxide.and water. But he needs right proportions.. Baking soda = sodium bicarbonate. With sodium carbonate reaction:
John Cuthber Posted January 4, 2015 Posted January 4, 2015 Getting "the right proportions" is almost impossible. Exactly how much acid did they spill? However, using lots of baking soda or washing soda (which is a lot cheaper) will stop the acid damaging the concrete. You can always wash away the excess soda with water.
studiot Posted January 4, 2015 Posted January 4, 2015 The problem with using water is that the OP has said there is limited time. I expect the resin coating they intend to apply requires a perfectly dry surface to bond to or it will fail. I cannot honestly see the need for the bicarbonate. We used to use sulphuric acid to clean off concrete from tools and it acts very quickly. So quickly that there will be no caustic residue left on the concrete. Any damage will already have been done. I further assume that the grinding is to remove the loose (damaged) material to provide a sound surface for bonding. So once again, why not just grind it out?
John Cuthber Posted January 4, 2015 Posted January 4, 2015 The best answer, from a lot of points of view, is simple. Stop spilling acid.
studiot Posted January 4, 2015 Posted January 4, 2015 Stop spilling acid Ha I like it. To dream the impossible dream. I further assume that the resin coating is to protect the concrete against further damage and will itself be acid resistant. Therefore in the future spilt acid will remain unneutralised and a potentially hazardous. In those circumstances, bicarbonate neutralisation and washing off would be beneficial.
platosgal Posted January 4, 2015 Author Posted January 4, 2015 ok now...if we remove the existing acid, neturlized it with soda, and rince it clean with water..then apply this acrylic coating..in the future, after we are done with the work will the acid spills react with the acrylic and become hazardous?? thank you all so much for the imput, I am struggling with this job and we start is soon, and I do not want any surprises AND ..when you say "polish the acid out" do you mean, rince the areas well with water (perhaps power wash) and use a commercial buffer and black pad OR screen to pull out the area?
John Cuthber Posted January 4, 2015 Posted January 4, 2015 (edited) Make sure the concrete is completely dry before you put any sort of covering/paint/resin on it. Also, when you have put the acrylic down; if they spill acid on it one of two things will happen. The acid will attack the resin and damage it or the acid will sit around on the resin until someone slips on it and falls into a puddle of acid or whatever. At the moment, the concrete is acting as a neutralising agent and it destroys the spilled acid. The acrylic won't do that. So you will need to make sure that there's always some way of cleaning up the acid before it corrodes something. Lots of water and a drain or maybe calcium carbonate (crushed limestone). Or, you could stop people spilling acid. Edited January 4, 2015 by John Cuthber
studiot Posted January 4, 2015 Posted January 4, 2015 (edited) platosgal AND ..when you say "polish the acid out" do you mean, rince the areas well with water (perhaps power wash) and use a commercial buffer and black pad OR screen to pull out the area? With the greatest respect, you mentioned polishing the concrete in the first place. The only way I know to polish concrete is with commercial grinding equipment, just as any other form of industrial 'polishing' for finishing something. You can obtain a glass like finish this way. If you just mean apply wax polish and buff well sorry if I misunderstood. So commercial grinding would give you whatever finish you seek (it's a dirty, dusty process unless you use spongejet http://www.spongejet.com/technology.php) But you must remove any loose material or the resin will not adhere. Some resins are acid resistant, some are not you need to consult the manufacturer. You can also get acid resistant floor paint systems, sorry I can't remember the names at the moment. Beware all resin coatings generate a lot of heat while setting. Follow the instructions exactly and do not be tempted to apply more thickly than recommended. I have seen some resins get so hot they literally caught fire because the contractor tried to put them on too thickly, instead of building up in layers. Edited January 5, 2015 by studiot
platosgal Posted January 5, 2015 Author Posted January 5, 2015 OK to further complicate things..here is a new list of chemicals in other areas of the boiler room they have advised me we need to take care of prior to installing the finishing product (Finishing product is : water based acrylic..but I digress) So here is the potential chemicals in and on the concrete Amine-Aquatrol WPC 40 Nitrate-Aquatrol WPC 72 Phosphate Aquatrol QPC 20 Sulfite Aquatrol B-4467 Bromin Aquatrol C-2780 Sulfuric acid N/20 Sulfuric acid Aquatrol WPC 78 Amine Aquatrol WPC 62 Inorcanic Salt Aquatrol WPC 1050 Potassium Hydroxide Aquatrol WPC Sodiam Tolyltriazole Aquatrol C-2780 Aquatrol B-3700 WHEW!!...I will be in England in March..looks like you boys are all in England I will gladly buy dinner and drinks for any one of you who crack this code and help me with this I am overwhelmed...damsel in distress to the stress extreeme Please tell me water and bakingsoda will handle the above! Or ...let me know what to do to stay safe and do the work properly Many many many thanks Bren
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