Dwell times for detergents and chemicals.

[HydroBlast]

Hey gents,
I've read your informative posts, and have learned so many trade secrets. (which by the way I'm so grateful) You've all talked about which chemical for what application, but never the dwell times for any particulate incident. I realize the condition of stains requires longer times for chemical to react, so how long should oxalic acid or detergent dwell to just say; brighten a dark sidewalk? Thanks for your replies!

Dennis

 

[Bleemus]

Oxalic is the last thing I do on concrete and will oftentimes just let drive away after laying it down. So, to answer your question, the dwell time I use on oxalic is until the next rainfall.

 

[5 Star Johnny]

Oxalic is the last thing I do on concrete and will oftentimes just let drive away after laying it down. So, to answer your question, the dwell time I use on oxalic is until the next rainfall.

Bleemus, it's not clear by your response as to whether you use oxaclic on concrete, or not. Normally, a good cleaning with whatever cleaner and equipment you use is enough for most situations. Although oxalic will brighten concrete (more so on aged), the difference is negligable on newer concrete if cleaned properly. Oxalic will work well if you have a lot of metal deposits, and you COULD let it dwell for 24 hours. Oxalic is a unique acid in the respect that it continues to work on the contaminant, rather than "die" once it hits the contaminant, like most other acids.

My biggest problem with your comment is leaving the oxalic sit until the next rainfall! You are endagering the owners, their pets, or anyone or anything that may walk on the surface until the oxalic is diluted or washed clear. Even if the oxalic is left to dwell and eventually crystalizes, it will likely "reactivate" with a light rain. Even if someone walks on the surface with foot protection, they may carry the residue into their home and make some really interesting footprints on their carpet or wood floors.

My advice on dwell times? Call the manufacturer, call your rep, and test.

 

[itswillist]

Same here .. I always rinse the oxalic off after I use it on concrete (or anything) The dwell time for oxalic is different for each situation, depending on what your trying to clean up. One section of the driveway or carport may require longer dwelling than another, just let it sit untill you see the change .. An average dwell time for me is around 15 - 20 minutes, but sometimes longer if the area needs it ..

 

[douseahouse]

where?

where can i purchase this type of product?

rando