Is it possible to remove the mast head and fill the interior of the mast with expanding foam then replace the masthead to keep the mast afloat.

Chris

I don't know if that would work. I thought of that but was concerned about expantion.

The problem with the expanding type foam like great stuff is that if the skin that forms on the foam breaks down or is damaged, the foam will absorb and hold water. I have thought of removing the mast head and packing the mast with some polystyrene (sp?) you know the stuff the cheap coolers are made of. You can buy it in sheets from the home improvement center and glue it together with liquid nails.



Haven't given it a try yet though.

Thinking about the mast floatation agian, if you could find some of those colored round foam tubes that they sell at walmart and other stores, the ones about 4" in dia and 4 feet long for kids to play with in the pool, you could remove the mast head and stuff a couple in the mast. I would apply a little marine adhesive caulk to keep them at the top of the mast. The foam these things are made of is an ideal foam for this application, I think, and the size is just about right.

Would only work if you did not have a comptip.

Just a thought.

Using those "noodles" sounds like a good idea. The larger diameter one (4") gives appx. 30lbs of lift. Two of those in the mast may be addequite. One would have to do a little experimenting.

Putting those things inside your mast wouldn't do anything unless your mast isn't sealed.

It would be far easier just to seal the mast. If nothing else, foam in the mast will add weight aloft, which is never a good thing. As flotation results from weighing less than the water displaced, it would seem that adding foam to the inside of the mast could make things worse, as foam weighs more than air - you'll be increasing weight for the same amount of displacement. The only benefit would be that it could keep water out - but only if it's a closed-cell type that is not going to break down in the constant flexing of the mast. If it breaks down and your mast is not sealed, it will absorb the water.



Adding a float to the outside of the mast increases displacement, which is why they would work better. But you're still adding weight and now drag aloft.



Seal the mast. If you want more flotation, add a float of some kind, but I wouldn't mess with filling the mast.

Just a thought on the mast flotation thing. What if one would attach a sheave toward the top of the mast on the forward side and possibly one at the base of the mast then run a continuous line through the two (this would be similiar to a halyard). With a clip or two attached to this line you could attach a throwable cusion (or something lighter) which could be hoisted to the top of the mast thereby keeping the mast from sinking. after righting the boat the float could be lowered thus reducing windage. If you could attach a noodle to this line the bouyancy would be there without the weight.



Just a thought.



Clayton

H16, S27

I know of a least one bigger cat turned turtle that was able to right using that method. The cushion was run up the spin halyard (I believe) and that was enough for the crew to get the boat back on its feet. A dedicated halyard for just such a purpose might not be a bad idea. Since you're required to carry a throwable cushion, it could serve double duty.

Why does the floatation need to be on the outside of the mast to add floatation? I can understand how it would be bad to use expandable foam but on epost thought of using a floatation tube. I guess I just do not understand the dynamics.

I'll apologize up front if this sounds too much like a school science class!



Again, to float, you need to weigh less than the water you displace. So, take some object of a given volume, and put it in the water. It will push some water aside as it sinks in. If it weighs less than the water it has pushed aside to make room for itself, it will float. If you increase its weight for the same displacement, it will sink more, keep adding weight and it will sink altogether. As it sinks in, you will be displace ing more, but your reserve is going down. Now, if you add something to the object that increases volume with light weight (like an exterior foam float, tube, cushion, etc.) you increase the amount of water that will be pushed aside, but the material you have added weighs less than the water it is displacing. So, you have increased displacement with little weight, therefore adding to "bouyancy". If the material added was something like, oh say, lead, you would have increased displacement but what you added would weigh more than water, and you reduce bouyancy.



You can set up an experiment to illustrate this with a measuring cup with water in it, and a few small objects like a piece of cork and fishing weights and such. When you put things in the water you will see the water level rise in the cup - an cheesy way to measure displacement.



So, adding something like foam to the inside of the mast does not increase displacement, but does increase weight, because foam weighs more than the air normally inside a mast. This would reduce bouyancy.



Adding a block of foam (or a tube, noodle, mast float, cushion, etc.) to the outside of the mast increases displacement, and adds some weight. But, due to the nature of the material, it weighs significantly less than the water it can displace to make room for itself. You have increased your displacement but added little weight - this would add to bouyancy.



Your other alternative would be to make your mast lighter for its given volume - a fair less practical solution unless you feel like spending for a carbon mast with the same dimensions as your metal one. ;-)



Hope that helps!

Thanks, I guess thats why I'm a police officer and not a science teacher. I was just thinking the foam in the mast would act like the foam sandwich in the hull but now I understand.

I think the foam as flotation as any other device (even a boat) works on displacement. With the foam in the mast it is not displacing anything except air on the inside. The mast itself is doing the displacement. While adding foam you also add weight and not volume. Look at it as adding bricks to a boat with out changing the hull size. At some point the weight to displacement ratio will go into the negative and the boat will sink. With the foam on the outside it will actually displace more volume (water) and thus add bouyancy. A previous post said to seal the mast that would be your best and first attack on the situation.



JMO



Clayton

Yes it all makes sense. At least I am not the only one who thought it might work. Ofcourse if there is foam in the masthead and the mast did leak somehow the foam would keep the mast from filling with water and maybe still provide it with some bouyancy.

One of the best ways to ensure that your mast is sealed is to simply put it in the water the next time you go sailing. Push it down a bit and if you see bubbles, note where they come from and seal those areas with silicon or 5200. Previous to this you can get a good cut at it by putting some sealant on and around all the rivets and joints on the mast. Not pretty, but then neither is trying to right a boat with a flooded mast!



Also, it is sometimes advantageous to drill a small hole (mine is near the base) and thread a screw into it. You can then remove the screw and the hole can act as a drain if water does get in somehow - put a dollop of sealant on the screw when you put it back in. It's amazing how, just from rain, you can pick up some water in a mast if there is a leak somewhere - being able to drain it means you won't start out at a disadvantage due the mast already having water in it.

Great tip thanks !!