chemical/ Acid used for wire cut brick cleaning and procedur

[nagzzz]

Dear all,
Can anyone tell me what chemical/ acid is commonly used for brick mortar and stone wall cleaning?
I tried a few options from the local market but not satisfied with the results. I tried Fosroc reebaklens, rseal cleaner and local acid too.

[girishd]

As far as I know, its not easy to get the concentrated acid for retail customers. The folks who do acid wash are the only ones who can get them through their channel.

The local acid as you mentioned is not good enough for tough cement deposits on stones. PM me if you need contact for Acid Wash work. I am about to start the same work at my place in a couple of weeks

[nagzzz]

Thanks Girish.
I tried Fosroc Reebaklens. But it was still difficult to remove the cement stains. Finally i ended up giving it to a local guy from Rammurthy Nagar. He is charging me Rs 5/- for acid wash and 15/- for Chemical Wash.
regards,
Nag

[biddappa_c_b]

ClayBlocks after acid washing

AfterWashing.jpg (252.32 KiB) Viewed 9899 times

ClayBlocks before acid washing

BeforeWashing.jpg (260.69 KiB) Viewed 9899 times

Hi Girish and Nagzz,

House is constructed using clay blocks + Stone. My engineer has done a shabby job of not taking care of the stone and clay blocks while plastering and cementing work. Hence lot of cement on the same. Now Acid washing is being done but the acis wash person told me that the workers have been careless and hence they need to scrap a lot to remove the cement. Hence he said that even after acid wash it is not showing great results that it should show .. See some the pics attached

[girishd]

@biddappa_c_b

We are using stone + vertically perforated clay block and currently have same issue. It is very difficult to protect the walls from concrete spillage during roofing ...

From your attached snaps, I think the acid wash guys have done reasonable job. Now you probably need to painting for the wire cut bricks with red oxide paint. Please check with your architect what they follow. If you need info, I can also check with my architect and get back.

[nagzzz]

Thanks Biddappa for the Photos.
I have had the same issue as yours. To be honest, your brick work still looks much better than what has been done at my site. The Acid wash at my site will finish in a day or two. Chemical wash looks much neater.
Instead of red oxide, i have gone with Touch wood/ Varnish from Asian Paints. It is just brushed on the surface. Good thing is it lets you keep the natural look on the brick and gives it a Shine.
Bidappa- how much is your contractor charging you for the Acid wash? I want to negotiate with my contractor too . And just to add, your house and my house concept is almost similar. Wire Cut and Size stone masonry. Where is your site located btw?

[biddappa_c_b]

Hi Girish and Nagzz, thank you for your replies.

Below is the quote given "Preparing Surfaces of Stone masonry and POINTING with CM 1:4 including Acid Washing, Curing & Scaffolding, etc." = 30 Rs perSft.

My house is actually used Load bearing clay hollow blocks, stone and in some areas regular bricks. What is the difference between Chemical and acid wash? Is chemical wash better?

Thanks for the idea of Red oxide andTouch wood/Varnish. As you have seen in the pics attached, if I use TOuch wood/varnish from Asian paint will the white patches still be there or will it be covered and have a shine?
Also with the Touch wood/Varnish, what is the maintenance? do we have to redo it after a while? What is the cost your contractor quoted for Touch wood/varnish painting?

Need your suggestions.

My house is getting constructed near Abhiman studio/BGS hospital.

cheers

[nagzzz]

So I am in the East and you in the west
Chemical Wash is more easier. It is just applied using a brush and that's it. No rubbing and no curing. The Chemical used is highly reactive (no brand name, but supposedly requires license to source). Not sure which is better.
Touch wood is just applied directly with a brush. My Contractor has quoted 5k as labour for touch wood. All white patches and deposits vanish with touch wood. basically, the white powder is because of the minerals inside the brick that come to the surface and react with Air. It also helps you retain the original color of the brick. Red oxide on the other hand will change the color, but still a good choice. I would suggest you go ahead with Varnish. If you want to first give it a trial, just buy 1l of Asian Paints Clear Synthetic Varnish and try on one of the surfaces. Go ahead if you like the results.
Sorry that I cannot share photos at this stage (popular superstition at home )

[biddappa_c_b]

Hey Nagzz, thank you for your reply appreciate it.

I will talk to my architect on the same.

Superstition? what is that?

[biddappa_c_b]

Hey Nagzz, you mentioned touchwood/varnish from Asian paints, can this be applied on external clay blocks? Will it sustain the weather conditions?

thanks