Re: keel weight?
More on keels for the folks interested in this aspect of sailboats:
Here's a photo of our Hunter yacht that we keep on Lake Superior:
I have the boat in my shop this winter for new paint and refits to electrical and navigation electronics. You can see the keel under there. This boat has a swing keel so she draws 2 feet of water with the keel up and 5 feet with the keel down. But the keel is neutral buoyancy and it only weighs 65 lbs. The boat is very heavily ballasted (47% of displacement) with cast lead ballast under the cabin sole. The ballast weighs 1300 lbs.
With the keel up she can be sailed in light winds but she slips to leeward pretty bad if the wind picks up much above 7 kts and she'll barely sail to weather close hauled clawing her way ahead at about 1 kt. With the way I have the standing rigging tuned, drop the keel, she locks right in and she'll point at just about 40 degrees with a neutral helm and go 7 kts thru the water. This boat is the best example of what the keel does for a sailboat.
So for the OP's original question on how much does the keel weigh? The keel can weigh almost nothing. It is merely a foil or "wing" that counteracts the thrust of the sails. The ballast CAN be in the keel, but it doesn't have to be. The keel makes the boat point and keeps it from slipping sideways thru the water. The ballast provides the righting moment on the hull. Where the ballast is placed, and how much is used, determines how the boat attempts to right itself when it is knocked down (sails touching the water) or rolled completely inverted.
This is where sailboats differ from powerboats in design - a sailboat can be rolled completely inverted in heavy seas and the wave and wind action will place the ballast off the center of rotation of the hull and it will right itself (usually). Or a sailboat can be knocked down (laying on its side), ease the mainsheet and she'll stand back up. But none of this has anything to do with the keel. It has to do with the ballasting.
Now, this Hunter is a FUN boat to sail. It does not have a more flat bottom like the Catalina's do. So it heels easily (more tender) at first, despite the heavy ballasting and long fin keel. You can run this boat with the rail under the water in 12-15 kt wind carrying full sail, but she won't go any further because the hull design causes it to "stiffen up" as the heel angle increases. It takes a big rogue wave to make her roll and pitch to knock her down. BUT - you're not using your keel effectively at that heel angle. The keel has to be more perpendicular under the boat to be most effective. So the boat is slow at excessive heel angle. Reef the main down and hoist a smaller jib (or furl it), then the boat sails with less heel, the keel is more effective, and she goes faster that she does carrying too much sail.
Other sailors will know what I'm talking about - bigger sailboats are nice for cruising with 4-6 people onboard because they have a lot of room. You can sail a bigger boat all day and get bored because it doesn't really do anything exciting. Smaller sailboats 18-26 feet are pure fun because they're so responsive to helm input and sail trim. And the type of keel she has under her will determine just about everything about her handling characteristics on all points of sail except a run.
Hope this helps folks understand better what the keel is all about on a keelboat. Powerboats have a keel too, but for the most part the bottom of a powerboat is pretty flat. This is kind of a humorous rundown of why we see some powerboaters have so much trouble with docking their boats
It's Not Your Fault!...Docking a Power Boat is Difficult | Docking