Re: keel guard
I would like to say that I am a real believer in the Keel Guards. I initially wanted the guards for the same reason as you, beaching was rubbing off the gelcoat on my new catamaran.
However, they did not recommend that I install the guard as my cat sits on a trailer that total supports the keels, full contact.
After giving it a lot of thought I decided the money spent was worth it if it worked, but that I would install it differently than instructed.
1st, I lifted the boat as was previously suggested, using the trailer tongue jack, and subporting the hull on 4x4's, then lowering the jack.
After prepeping as instructed, I installed the guard on the bottom edge (keel) only. Then lowered the boat onto the guard and let it sit for 2 hrs in the summer heat. After that I installed the guard from the stern to the keel, forcing the guard away from the keel to try to keep it from "moving" during loading and unloading.
Am I ever glad I installed the guard. It protected the keel when my son-in-law accidently grounded us on the hardpan of the Homosassa River. 2 holes were torn in the guard but no damage to the hull. My son cross loaded the boat onto the trailer and left severe rub marks on the guard but no damage to the boat. And it kept the sand from damaging the keels when beaching.
I don't know how long it will last, no problems so far from the sitting on the trailer, but there have been some delamination of the plastic from the 3m adhesive in areas well away from the bottom edge. I have repaired those areas with 5200. I will continue repairing until no longer reasonable, and then I will install new guards.
Sorry for the long post but I really like this product, it has saved me from a lot of damage and subsequent insurance claims.
Bob