Using brick acid

[marsaday]

I am about to clean my internal chimney (attic conversion).

Is it really bad on the skin and would i be best using plastic gloves?

I am just going to rub the bricks with the cleaner using a soft hand brush. Do i need to apply pressure or does the acid just do the job for you?

How long should i really leave the acid on for ? It says 2h's, but the bricks are not that bad. I just want them cleaned up a bit really.

Afterwards i will point up the chimney as i have raked out the old mortar. Once this job is done i intend on applying linseed oil and solvent to make the bricks look good.

Here is part of the chimney

View media item 35382

 

[hotrod]

It is very bad - it gets right on your lungs nasty nasty stuff. I've only used it out doors and only left it on for max 1 hour. You can even see it smokin'

 

[^woody^]

You need to wash the acid off the wall, otherwise it will remain and will continue to rot the existing cement and your new pointing

The longer you leave it on the wall the further it will soak in and stay there

You just need some on a brush and rub the bricks or stains individually

You do know that brick acid only works on cement and wont do anything for any other stain?

You may be better off with a wire or flap wheel on a grinder or in a drill

 

[marsaday]

Ok, i will see how i get on with a water wash first.

I can chip off the cement by hand pretty easily.

 

[tim00]

The other guys have it dead right.No acid.
Some angle grinder stripping discs will work.

Even the small hand held concrete grinders -from a hire shop.

Or, take an old, soft brick and rub down the in-situ c/breast.

 

[amwc]

The best thing I found for acid washing is heavy guage rubber gloves a fairly strong acid mix and a wooden finger nail brush then you can get into the smearing quite well and definately wash it off.

 

[r896neo]

I have found a flap wheel in a drill to be very effective.