Aluminum Crossframe and Keel Plate Upgrades

The original crossframes and keel plates (and side frame plates) in the GII and other post 1990 Folbots were injection molded, polycarbonate. Brass screws in the crossframes mated with keyholes in the keel plates.

When Folbot upgraded to aluminum crossframes, they made sure they would be backward compatible with the older boats going all the way back to 1990.
I bought my GII in early 2004, the first year it had all aluminum crossframes.
The polycarbonate keel plates that the crossframes locked into were not changed at that time.
It was the next year (2005) that I discovered a problem with the upgraded crossframes. The crossframes hooked into the keel plates (and side plates as well) by way of an aluminum "bracket" that mated with the keyholes in the keel plates. Here's a bottom view of the new bracket in the old keel plate.
The screw heads in the poly crossframes rested on both sides and the bottom of the keyhole slot. The new aluminum bracket only rested on one side of the slot.


I was entering the boat from a dock, lost my balance and sat down hard on the seat. I felt something pop and found that the bottom bracket had pulled out of the keyhole in the keel plate. In addition, I found that the aluminum bracket had bent down at the ends.
This is the bottom of crossframe 5.


This is frame 3. It was bent later by front passengers stepping on the keel tubes.


Once the bracket was bent, it popped out easier with much less loading. Simply stepping on the keel tubes would pop it loose. That's when I began telling everyone to step on the skin, not the tubing. The water supports the weight just fine so no problem.
I sent pictures to Phil and we discussed solutions. He decided to switch to stainless steel for the little bracket and he had his injection molding house add some glass content to the keel plates. That almost fixed it but some people still had problems so he modified the keyhole in the plate to a half keyhole and that pretty much fixed it.


It's a little harder to lock the crossframe into the keel plate but it's much more secure once done.

Phil then sent out the upgraded SS brackets and new keel plates to anyone who asked for them.
I installed the brackets only on the bottom of crossframes 3 and 5 and I replaced the keel plates at those two positions. The problem never occured at the side frame plates nor at any of the other crossframes. Some people suggested doing the sides if you sailed your GII as there's much more stress on the sides.

Here are pics of the new keel plate with the modified keyhole and the old (bent) aluminum and new SS brackets.




It's been 12 years since that upgrade and I've had no problems.
jun17