: has anyone every build a kayak seat with the blue or pink 2" foam that
: thy sell at home depot or lows? if so how did you do it? thank you marc

Marc,
The best foam for carving your own seat is a high density, closed cell foam simply called Y20. I absorbs no water which means you will have to drill holes through it to let water drain through and will float away so fast in the slightest wind if you drop it in the water. Unfortunately, most foam suppliers do not carry it as it is very expensive and usually only comes in a large sheet. More than what you will need for one seat. The foam can be cut with a saw or utility knife, scraped with a surform and sanded smooth with fine sandpaper. It is so dense, you can cut it to within 1/4 inch and not feel the boat underneath you. This is of benefit in that you can get your center of gravity very low. Once shaped to your backside, you will never complain about your kayak seat again. Depending on where you live, you will need to do some investigating to find it. You can order pieces from several kayak manufacturers to build your own.
Rod