chirobob

You could try Kerosene, or even deodorised kerosene. All the asphalt companies over here use it to remove the tar from their dump trucks. Diesel will work OK. But I would suggest the deodorised Kerosene it's a little dearer than the normal kero, but more suitable for indoors application.

Alvaro, try a (Selfserve or automatic) carwash supplier, you should be able to get it through them, but it may be mixed with Sulphuric or phosphoric. It will probably be sold as aluminium brightener or acid wheel cleaner. You may also try your brick manufacturing companies to see if they know of a supplier.

Alvaro, most detergents are either pH neutral 7 ish- these are the ones that need alot of scrubbing (mechanical energy) to loosen up the dirt particles as you go up the pH scale towards 14 you get an increase in (chemical energy) that usually requires less scrubbing and just rinsing. The problem you have with higher pH alkaline detergents is that there is a higher risk of streaking and damage to plants etc if you don't pre-wet and post rinse. The same can also be said about acidic cleaners that have a low pH. In general most grime/dirt is more soluable in an alkaline detergent. To put it in perspective with an analogy most animal fats are slightly acidic in nature if you try to clean the fat off concrete it won't dissolve and therefore will mainly stay on the concrete, but if you were to treat the fat on the surface with a caustic (sodium or potassium hydroxide solution) pH 12.5-14 the fat would dissolve and the surfactant (carrier molecule) attaches to the broken up fatty acid molecules and allows it to mix with water. Allowing you then to rinse the surface without leaving a residue. Surfactants basically are a carrier molecule between the dirt molecule and the water that allow the water hating grime to be able to dissolve in water. When I was talking about the surfactant with the HF the role in this case is to allow the acid to stick to the surface increasing the exposure time before it runs off. This is particularly important with vertical walls. An example of a surfactant is standard diswashing liquid. The are however many different types of surfactants that perform better in either acidic, alkaline, solvent, waterbased, hot or cold environments. Eg a good surfactant for HF is an Octyl phenol EO 10, Hydrochloric Acid -Teric PE 62, Alkaline solution -Nonyl Phenol EO 9. Tiger Chemical Co has a good surfactant guide for different applications as do Dow Chemicals. I guess if you want to make your own cleaning agents the previous is fine, but may be a little over the top for most. But even if you don't wan't to make your own chems a little chem knowledge will make it easier to purchase chems. For example if I wanted to buy a truckwash the first thing I ask for is the MSDS and I check out the pH and what the active ingredients are. To many times these office jockey chem salespeople sell you something that is the worlds best cleaning chem. Only for you to find that you have to scrub like a monkey over and over the same spot. If you really want to get into the nitty gritty of cleaning with chemicals, it would be best to learn some basic chemistry particularly acid-base reactions as well as polar and non polar solvents and you will be able to clean just about anything. Regards Jason P.S as for the tiles you could spot acid clean with HF on the lime runs and use the alkaline detergent for the rest. I feel if you use Hydrochloric or phoshhoric acid on the terracotta there would be a good chance it will cause effluoressence.

Alvaro, what I would do to clean it every time would be to look for a mild truck/alkaline wash at say pH 11 to clean them with. I would just downstream this, allow it to dwell for 15 minutes, then clean it with a fan jet 25 degree or use a turbo nozzle. If the premises has a hot water heater you may be able to rinse it off with this if you hook up your supply hose to a hot water tap. Usually they will have a 1/2" (15mm) or 3/4" (20mm) fitting that you can hook into- check the water flow out of the heater will keep up to your machine. You may or may not be able to do this depending on your machine, but most pumps will handle water at 60 degrees. Just remember don't let it recirculate thru your pump. You'll have to remove the bypass to dump on the ground or somewhere out of harms way plus you'll have to plug off the bypass return on the inlet side of the pump. This should get you out of trouble until you can determine if it is feasible to get a hotbox. A surface cleaner would give you a great result in this situation as well. It makes the cleaning pathway nice and even and a whole lot quicker. The HF is hydrofluoric acid, if you don't have a lot of luck with the alkaline detergent wash, I would try the HF at 2% but you will need to add a surfactant to keep the dirt in solution, and you would apply it with a bucket and broom/truck brush with all your personal protection gear. Cheers, Jason.

Thanks for your reply John, I already have a few varieties of that on hand for my fleet washing, I'll give it a go this weekend. Regards, Jason

Troy, this is a pic of me applying HF @ 2% and the safety criteria, I religously follow when dealing with HF. 2 x Chemical suit inner + outer, full face respirator, hard hat , ear muffs to keep hard hat in place, steel capped chemical rubber boots, disposable ntrile gloves under PVC chemical gloves.If I am dealing with any chemical I wear this at all times when applying, only when rinsing will I take the mask off. I would also be wary of mixing two chems together to make the HF as you need to know """"""""EXACTLY""""""" what is going on with the reaction to determine to """""EXACT""""""" percentage of HF. Cheers

Rod, At what concentration are you applying this at? I tried earlier on this year to get some sil-o-wet sent over to Australia along with a couple of other things. I think the order was worth $2000 US, paid by VISA, everything was going well and the owner "John" stepped in and canned it, saying he didn't want to deal with international orders. Frustrating to say the least! Anyway, I was thinking of applying hot carwash wax to get the same effect. I haven't done a housewash before, so I thought I might try it out on one of my mates house to see how it goes. If it works well I might try to push this a little. regards Jason

Try brushing on HF starting at 1-2% with a truck brush on an extendable pole. Make sure you wear a full facemask and PPE gear. If this doesn't work try increasing the concentration factor up to 5 % and then 10% but be very , very careful. When you rinse it off, I would first give it a low pressure volume rinse followed by a high pressure rinse. Jason

Are you going to use this for your brick cleaning Steve? Jason

Which acid in particular is in the rust remover? Oxalic, Hydrochloric, Phosphoric or sulphuric, Sulphamic, Glycollic?

Paul, here you go I tried to post the complete series of these on the board, but had problems posting them, so they are on a couple of the other boards under Rust Removal.

Paul, I woud stick to the Phosphoric Acid, I have never used it combined with Sulphuric though. I buy the Phosphoric at 85% and dilute it down to 40% this is inline with most of the commercial rust convertors(you can also add a surfactant with it. I am going to be doing an access road at a steel mill on Tuesday 13th with rust on the concrete 500m square, so I'll take some pics and post them on the board. I tried using oxallic on rust ages ago and didn't get results even close to the phosphoric effect. Cheers Jason