brick staining

[bkel]

g'day all, just got a call from a client who has approx 350m2 of retaining wall (old as the hills) that he needs cleaned. There are some new sections that have been re-laid(which are no problems) and the remainder is covered in a white hard residue. To me it looks like a calcium build up, with some sections of efflorecence, but the client is adament that it's clay staining! The wall is old, and has very little drainage, so there really is no where for the excess to go except through the mortar joints. It's this reason that I feel its efflo, but it's also for this reason the client claims it's clay. A test patch with soap and hot water proved nothing as it didn't budge, and I am thinking a solution called 'noskum' which has an amount of HF in it may be the answer. Any ideas? Bare in mind I'm in Australia and dont have access to the solutions you guys have, so any base products would be much appreciated.
Brett
p.s cheers chirobob for the mitcham lead, went well

 

[CaroliProWash]

Check out eacochem.com . They have multiple cleaners for about anything brick or stone related. If shipping to you is not possible, their website also has the MSDS on the site so you could at least look up the base chems as you said.

I believe you're right and you should tell the guy who the professional is!

Good luck

Celeste

 

[chirobob]

Brett, the Noskum from memory has about 1% HF with 30 - 33 % HCL. I haven't found this to be strong enough with some past issues and unfortunately the only way is to dose it yourself ( far cheaper as well). Were you using hot water at high pressure or just trialling by hand? One of these days I'll have a chance to drop you a line. If you need more info on the HF I have some good suppliers.
BTW glad it went well with mitchum, hopefully a few more have contacted you.
regards
Jason.