I have done many Super Clean (lead dust cleaning) jobs over the past 5 years. During this time, I have used an assortment of hepavacs approved for the cleaning of lead dust.
One of the hepavacs, which I no longer use, is the Mastercraft P4511HVAF-R. The reason that I no longer use this machine is that although it cost twice as much as any of the others that I have used, it is the least effective and in my opinion it is a defective product.
The biggest problem with the Mastercraft is the hose. It comes apart from the machine at the slightest resistance or pull, causing a breach of any proper air tight seal. This defeats the purpose of a hepavacs entirely because it contaminates the area which may have already been cleaned. Most of my workers would refuse to use it, and when some of them did use it, they often returned it with duct tape on both sides of the hose. Duct tape is not something that you want to see on a machine costing $600.
The Mastercraft also has the least suction power of any of my machines, and the filter is $165 for a new replacement, plus $20 for the paper (intermediate filter).
The Mastercraft also has a poor design. The exhaust, which does consist of discharged air that is processed through a filter (which does meet EPA standards), is very high on the machine and the direction and height of the discharged air can blow the unvacuumed lead dust back into the air, causing it to settle where the vacuum has already cleaned. If the lid is turned to where the exhaust comes out the back, then the power cord comes out the front of the machine, making it easier to get the cord stuck on things because you are pulling the machine in the opposite direction of the outlet. This is not a problem with the other machines which expel exhaust from the entire circumference of the machine, causing less wind.
I would never buy one of these machines again. I have tried to sell mine to other cleaners for half of what I paid, and I am unable to find a buyer.
Note – here is a video of the vac, and the hose coming apart