I bought this product after reading reviews on covering stained wood. My skirting boards kept bleeding through, even after 3 coats.
I must admit I questioned whether a 1 Litre can would suffice for all my boards, but I also didn't want to buy the 2.5 Litre (the price for the smaller can was bad enough!)
On opening the can, I was surprised to see that it was very watery, but this turned out to be a great advantage. I was able not only to get round the entire house, but there was sufficient amount left for me to give them a second coat!
The finished product is amazing. Touch dry in 15 minutes, and re-paintable in 45. Even after 1 coat there was no bleed through, but a second coat gave it an almost finished result.
This primer is very expensive, and I certainly wouldn't suggest that it gets used as a regular undercoat. But, for specialty jobs (like painting over stains or metal) it gives an amazing job, and is well worth the money. Without it I would probably have had to give the skirting boards about 5 coats before the bleed through stopped.