Concrete cleaning prior to sealing

[MoGas]

I had a new driveway put in a year ago July and I sealed it after 45 days of curing. We didn't use the driveway for that 45 days, so I didn't have to clean it prior to sealing. I have been told a few different ways to clean the concrete so I can seal it again before Winter comes around. I am getting conflicting methods and products from sales people of products and how theirs is way better than the others. I have also been told to just scrub it with muriatic acid, let it dry for a day or so, then reseal. Will any of these methods get the oil off the driveway? (The 62 needs a pan gasket and I haven't had the time yet to replace it) I'd hate to seal the oil into the concrete.

What methods and products have worked for you?

What sealer are you using?

Thanks,
Dave

 

[Rusty55]

If you are just sealing the concrete with a clear coat, don't waste your money. Sealing concrete is a big waste of money unless you are in a garage and you do an epoxy. There is no reason to seal concrete on an outside driveway.

 

[Hugh Heifer]

I just used Muratic to clean and etch it.

 

[jts560]

Before I painted a smooth concrete floor in the laundry room I pressure washed and etched it with phosphoric acid. I'm not sure that level of prep is necessary for sealing a driveway with a rougher finish. Figure out what sealer you are going to use and follow the instructions, but definitely degrease the oil stains.

 

[wfd175]

Because of salt used on the roads, it's common to seal concrete in Missouri. My driveway is on an incline so I use a little calcium chloride after shoveling to ward off any early morning ice.

Pressure washing sufficed for the product I used.

Here is a product prep note:

In order for the sealer to adhere properly, the concrete surface must be clean. Remove any dirt, oil or mildew from the surface and repair all cracks or other defects.

Use a solution of one part bleach to three parts water and a stiff, nylon bristled brush to kill and remove any mildew.


Use a pressure washer to lift and remove dirt and stains from the concrete's surface. Remove stubborn stains like grease or oil with a mixture of water and trisodium phosphate (TSP) and a stiff, nylon bristled brush.


Patch or repair any irregularities in the existing concrete.

 

[Markgyver]

I work for an engineering firm that specializes in concrete restoration.
You do not want to use Muratic acid. Muratic acid will open up the pours of your driveway and alow salts to penetrate the surface.

Use a penetrating sealer containing silanes and siloxanes are among the best. These chemicals partially fill the pores of the concrete matrix and simply don't let the water and oil molecules pass through and into the concrete but still allow the concrete to breath. The liquids stay on top of the surface.

Many of these products are available at specialty concrete supply stores. Most major cities and towns have these. Open your Yellow Pages and look under Concrete Supplies. Beware of heavily advertised consumer products. These often contain silicones or other similar chemicals. Avoid these if possible because some of these products are film formers and simply lay on the surface of the concrete. Some of them don't allow the concrete to breath. This is a bad thing especially if you live where the temperature drops below 32F. Water vapor from the soil passes through concrete and the film formers can block this movement resulting in damage to the concrete surface.

I get a product at White Cap if you have those locally.

As far as cleaning just pressure wash it use a mild detergent for any oil stains. I like using laundry detergent.