from what i learned, sintered can not be added to easily. the guy that works on my board said they'll grind the base down to get gashes out, but if its really bad, they had to add another “sheet” because you cant add spots like you can with p-tex. sintered is harder to put huge gashes in than extruded, but when you put a very very deep one, the board is pretty much considered trash, because it costs too much to grind it that far down and build it back up again. thats why most people (other than pros, their boards are free) resist hitting jibs with a deck with sintered bases.of course this is word of mouth, i take extreme care of my sintered board for this reason alone 😉
