The install of the KS System 4 'rope control' skeg is 'on hold' right now as the 'Optional Adapter Box' is back-ordered.
So that's my first bit of info: Unlike the KS cable control skeg 'kit' which had everything I needed for an install when I bought it a few years ago, the newer System 4 line control kit doesn't include the 'box' which goes inside the kayak and is required to make the control box waterproof.
Make sure you include it with your order!
This skeg install is for a friend's Pygmy Murrelet boat. So the 2nd bit of advice is to install a skeg in this boat when you are building it. The builder/owner is a very skilled and experienced paddler (Paddle Canada Level 4) and if she says the boat needs a skeg I believe her!
I was worried that the ABS plastic skeg box wouldn't be protected from side forces when gear was pushed into the back of the boat.
I've seen leaks in commercial kayaks around the base of the skeg box.
It's a difficult spot to work as well, so building a good flange around the installed skeg box looked like it would be tricky.
I built a low plywood box from plywood glassed on both sides, and fixed that in place first. Then I installed the plastic skeg box. It's difficult to install the skeg into the very sharp angle of the hull bottom on this boat, like most S&G boats where the two main hull panels are pulled together at the stern. If you are building with the idea of installing a skeg, working a 'flat' along the keel line at the stern would make for an easier job.
The ABS plastic bonds with epoxy if cleaned with acetone and rough sanded before bonding, in my experience. I bond ABS hatch rims this way and haven't had any problems, so far.
I just realized that I forgot to grab a pic of the installed skeg box; sorry.
More pics to follow when I get the boat back in the shop to install the control box.