How much foam is needed to float a V222 in a knock down?

Jan 25, 2017
147
Macgregor V222 Kentucky Lake
Here is one for the group. As I approach my splash date, I find myself turning to the subject of "self-righting" and floatation. I've seen a few posts on the subject, but nothing definitive. So here are some questions:
1) How much does a V222 weigh (unloaded)?
2) What amount of foam is needed? Sq feet etc?
3) What kind should I use? Does the closed core / insulating foam from Home Depot work?

I love these types of subjects and can't wait for the opinions to ensue! You guys are great and the debates are half the fun!
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Nothing about foam will add to a boats 'self righting' ability.

As for how much, what you really want to know is what the net buoyancy of the boat is; the difference between the stuff that wants to sink vs the stuff that wants to float. You don't need to support the full displacement with foam, just the delta amount that makes a boat sink. Just like a human in the water. A 200lb man is 'floated' with 10lbs of foam displacement.
 
Feb 28, 2018
39
MacGregor 25 Orlando
Todd, Sailboatdata.com - http://sailboatdata.com/viewrecord.asp?class_id=188 - says the boat displaces 1800 lbs (yeah, I know, that doesn't take into account mods or your stuff). At 62lbs/cubic foot, 30 cubic feet of foam would basically lift the boat out of the water (placed beneath the keel). Like Jackdaw said, you don't need anywhere near that to keep from sinking, but it is a good place to start to make a guesstimate - since the plan generally is to never test the anti-sink plan! I can't imagine you'd need more than 5-6 cubic feet, but that is a guess.

Anything closed cell should do the job. Just make sure it doesn't float out the hatch!

Your keel is what is going to right the boat in a knockdown! Hopefully, it is locked in the down position the day it happens!

Try not to get too crazed about it. If you're really worried about it, as my sailing instructor used to say, just sail more conservatively. The boat handles more than we do generally.

Fair winds.

-Peter
 
Jun 25, 2016
65
Venture 21 Minter Bay
My V21 has chucks of styrofoam-looking foam under the cockpit seats and floor starting about where the quarterbirth platforms end. I'd have to crawl back there to measure and count... I think there may be more in the bow, forward of the v-berth access cutouts...along with some lead bars (?).... I wonder if that was a PO modification of the foam and balast... There are lots ofmfolks who've removed their decks and redone the whole interior, so they may have ideas on what ought to be there.

Cheers!
 
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
When I restored my Mac 22 (I have lots of pics), I replaced all of my foam. If you go to my profile page, there is an album that shows the restoration pics. The original foam had been eaten by field mice, made into nests and it was nasty. If your Mac 22 is like mine, then under the cockpit you will find two ridges fiber glassed into the hull running fore and aft. I filled that space in with the thick pink foam boards . I filled it from the hull to the underside of the cockpit. All of the scraps from cutting the foam boards to size went into the V-berth and were secured with liquid nails.
 
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Jan 25, 2017
147
Macgregor V222 Kentucky Lake
Thanks rgranger! I really need some advice on this keel issue! The list never ends... check out my post on "why re-glass the keel?"
 
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Oct 19, 2017
7,733
O'Day 19 Littleton, NH
If you are serious about calculating the amount of foam needed to keep your boat afloat, consider what the goals are. Do you just need a platform to sit on until rescue, are you going to try and tow the swamped boat ashore, do you want to bail and possibly recover? If you are considering an 'at sea' recovery, you need to keep the gunnels above the water and close up any self bailing scuppers or bailing will be fruitless. If you want to tow it home, you need the bow not to sink and if you just don't want to swim, than just enough to keep her at the surface will do.
Note, bigger boats don't even try for positive flotation. They go to sea and stay upright. They can take a knock down, even roll and don't take on enough water to sink. Keep your hatches closed. Breaching the hull is a different matter.

- Will (Dragonfly)
 
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Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Take the boat to the truck weigh scales. Note the total weight. Put the boat in the water and take the trailer to the weigh scales and subtract the trailer weight from the total and you'll be left with the actual weight of the boat.
 
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Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
Take the boat to the truck weigh scales. Note the total weight. Put the boat in the water and take the trailer to the weigh scales and subtract the trailer weight from the total and you'll be left with the actual weight of the boat.
That is helpful but some of that mass has positive buoyancy. If did use that mass as your displacement, you would more than likely have enough buoyancy to bail and recover in the event of a knockdown. But don't forget that space on a V22 is limited and precious if you are going camping on the boat.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
That is helpful but some of that mass has positive buoyancy.
The OP asked what the weight was. If you can figure out what the positive buoyancy is, you can subtract that from the total.
 
Jul 29, 2010
1,392
Macgregor 76 V-25 #928 Lake Mead, Nevada
I have only been knocked down once rounding Palos Verdes in San Pedro Ca. It's commonly referred to as "Hurricane Gulch". Winds have been known to gust up to 50 MPH. Had Spinnaker up (dumb) and laid mast in the water. (scary). Released all the sheets and popped back up. Luckily hatches were all close. Didn't take any water inside. Lesson learned. Lake Mead also has has wind that come out of seemingly nowhere. Friend of mind got knocked down off Anacapa Island. When the boat righted the cockpit was full of squid.:biggrin: If ya wanna to get scientific, okay. My advice - pack flotation in all the spaces you don't use for something else. 25's have the entire area under V berth and under cockpit sole filled with foam. Sounds like you get a lot of wind on your lake. Also NEVER sail unless keel is down and locked.
 
Jan 25, 2017
147
Macgregor V222 Kentucky Lake
Thanks Freedom! I don't want to minimize the risk at all, but I've been sailing since I was fourteen and have "dumped" a lot of Sunfish and Cat's... that was always part of the fun and how you learn. That being said, I know when to release the sheets having pushed it to the limits when the consequences only meant a dip and a swim. That being said, I can't imagine I would ever turtle my 22. It would take serious wind and a serious lack of judgment (though I have been guilty of that before). I think an old sailor told me once "sail just below your comfort level, never exceed it and you will be fine." In other words, release the sheets before she dumps? Thanks for the advice... and I will pack the foam where I can. I believe the general consensus is about 6 to 8 cubic feet will float my V222.
 
Jul 29, 2010
1,392
Macgregor 76 V-25 #928 Lake Mead, Nevada
Definition of sailing, hours of boredom interspersed with moments of sheer panic.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
When I had an O'Day 222, I saved up 2-litre soda bottles, filled them with packing peanuts(free from work) and put them in a large hefty bag. I could take them ashore , and at least it was SOMETHING.
 
Oct 19, 2017
7,733
O'Day 19 Littleton, NH
When I had an O'Day 222, I saved up 2-litre soda bottles, filled them with packing peanuts(free from work) and put them in a large hefty bag. I could take them ashore , and at least it was SOMETHING.
Why did you fill them?

- Will (Dragonfly)
 
Oct 19, 2017
7,733
O'Day 19 Littleton, NH
I mean, why put peanuts in the bottles at all? They weigh less and are water tight without the peanuts. I like the free part, but I would think, either a bag full of peanuts or empty bottles, not empty bottles filled with peanuts in a bag. Did you not have the bottle caps?
How did you secure them in the boat? They just stuffed into an empty compartment?

- Will (Dragonfly)
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
The boat keeps me afloat. Bags of bottles keep the boat afloat. Peanuts keep the bottles afloat. I put the peanuts in to keep my hand busy so I wouldn't choke the other half. Then I ran out of peanuts....
 
Feb 28, 2018
39
MacGregor 25 Orlando
The boat keeps me afloat. Bags of bottles keep the boat afloat. Peanuts keep the bottles afloat. I put the peanuts in to keep my hand busy so I wouldn't choke the other half. Then I ran out of peanuts....
Ron recently finished serving 5 to 15 for manslaughter, with time off for good behavior! Apparently a temporary peanut shortage changed the course of his life....! lol
 
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