Acid washing bricks

[IDOC]

Ready to clean the brickwork
have heard reference to "acid washing" with diluted muriatic
any do 's or don'ts?

[Les]

Re: Acid washing bricks

Mix it around 50/50 - they recommend a more diluted mix but I found it a waste of time. I washed mine using a sponge, I avoided using a brush as it tends to splatter. I also only washed the brick where it was needed and avoided the mortar joints. Wear good latex gloves and eye protection. And the obvious, don't breath the fumes and keep it off your skin. It also helps to have a hose near by if you are working over concrete products. Any time I splashed it onto my pavers - I quickly hosed it off and no harm done.

Les...

[brokencookie]

Re: Acid washing bricks

Diluted muriatic acid is actually hydrochloric acid. You will want to wear gloves and eye protection at a minimum. This acid also likes to eat cotton. So your jeans will end up with holes in them no matter how careful you are. I would have water on hand for any spills. If you feel itching, you have probably gotten some on your skin and you need to wash.

Having said all of that I would do it this way. Put on your protective gear. Use a plastic pail and a sponge to apply. When you are done, rinse with a lot of water. You can also make up a basic solution using baking soda and water and use it the neutralize the acid when you are done. If you do not get rid of all of the acid, it will dry and form crystals. These small crystals will become hydrocloric acid again, when exposed to water. The moisture in your skin, eyes, mouth, etc will re-activate the acid so clean up is very important.

This is the same acid that your stomach uses to break down food. In diluted form it is not especially hazardous. However, a few simple precautions will save you some discomfort and stress.

[nissanneill]

Re: Acid washing bricks

Hi IDOC
I would reduce the concentration of the acid:water ratio a little due to the porosity of the firebricks and use a little more 'elbow grease' (physical labour) to clean any residual mortar off your bricks.
I cannot comment if you were using and trying to clean the refractory mortars but with the traditional portland:lime:fireclay:sand mixes, I would also use a soft wire, stiff nylon or brass wire brush to help loosen and break down the unwanted mortar.
Rinse the bricks well after cleaning.

Neill

[RTflorida]

Re: Acid washing bricks

I'm with Les on the dilution strength - 50/50 (I don't like to scrub forever); yes, this is strong and extremely harsh. the key is to only use ANY acid solution sparingly - where it is really needed and always flush well with water. Gloves, goggles, long sleeves, even a respirator are common sense. I too use a small nylon or stainless steel brush.

One thing I would not do - slide into a completed dome and proceed to apply acid solution....you most certainly will end up with acid burns somewhere on your body. Clean the interior brick as you go or scrape and brush without the acid.

RT