I purchased this item to seal my stamped concrete. Half way through the job the plunger leaked. I checked the seal, cleaned the bottom of the plunger and can. I couldn't get it to not to leak air when pressurized. I thought buying this brand was the right choice it was not. The result was after trying to fix the unit now the material clogged the made the unit useless. It is now in the garbage can. Disappointed to say the least.