I’m trying to get a bit more room in my kayak by lowering the seat; it’s a plastic Perception sea kayak. Would it be a terrible idea to simply take the seat out and sit on ¼" foam? (or shape a seat from a few layers of foam, but with a minimum thickness of ¼" or less?)
The current seat is bolted to the coaming (with a little gap between it and the hull when there’s no weight on the seat) so I assume that currently my weight is shifted to the hull mostly by way of the coaming.
FWIW I’m not a huge guy (5’11", 165#), the boat is (a hand-me-down) “designed for a smaller paddler” but I’m probably at the larger end of its expected paddler range.
(The other option is to remove/replace the thigh braces, but that feels like it might be more fussy than just getting my butt lower.)
If taking the seat out is not irreversible (in case you want to sell or pass this boat on), should be perfectly fine. The trick is to shape a 1/4" foam seat that will be comfortable for more a few hours of paddling. Stick the foam onto the bottom of the boat with some adhesive backed velcro. This more easily removable than cementing the whole foam seat to the bottom of the hull (which is the way to go if you feel fully comfortable and committed to the foam seat).
What model Per eptiin do you have, and what dimension are you trying to gain (such as more leg room to the foot pegs, lower center of gravity . . . Etc.)
I’ve used the CLC Happy Bottom pad in the past with good results. You can buy a cheap foam shaper to carve the bottom to make it lower and to fit the hull shape. The integrated hip pads can easily be removed or shaped to your liking.
I’m looking to get a little more knee room so I can move my hips a bit more (I’m trying to follow Paulo Oullet’s guidance on paddling from the hips but as it is now my legs are pretty squoze in; it’s hard to have the knee room to move one hip forward much)
Lowering your CG and getting more room by removing the seat sounds like a good idea in that boat. I bought a QCC that had an overly thick padded seat in it - it wasn’t comfortable and felt too high. I removed the pad and put a layer of Ridgerest pad (sleeping pad) on the plain seat pan and it’s now more stable and much more comfortable. Give it a try - keep the old seat if you think you’ll pass the boat along someday. FYI I used double-sided adhesive foam strips that come off fairly easily, but they’ve been in place for years now.