The importance of floatation

[Unsullied_Spy]

Definitely stuff it full of pool noodles, I sank my SuperVee a few months back and I had too much weight in it for the stock floatation to keep it up and it sank to the bottom. As we were recovering it we could still hear the motor beeping as the ESC waited for radio signal.

[CornelP]

Foam will not expand to break the hull, if it's the right one: do not use the standard sprays, but the ones adapted to a gun style dispenser. These will shoot the foam at a higher pressure and it will expand to 99% before even hitting the boat... I have used it a couple of times and it is perfect.
BTW, WD40 is slightly abrasive, so be careful with it on motors... very good water repellent, but moderate use...

http://www.home-is.co.uk/product_info.php?products_id=215

[Fluid]

I strongly recommend not using the NHP two-part expanding foam. I used in in a very stout 'glass sport hydro and it stiffened up the hull even more, acting as a structural part of the boat. But about a year later it started to shrink, pulling the deck down in a wavy pattern over 1/8" - so much that the hatch no longer fit. I had to cut it away from the deck, fortunately the deck popped back up most of the way. I prefer pool noodles anyway, that was an experiment - which failed.

BTW, WD40 is slightly abrasive, so be careful with it on motors... very good water repellent, but moderate use...

Abrasive - without solids? An odd property which I've never seen mentioned before.


.

[CornelP]

Well, this is what I was told by a guy that sells it. To be completely honest, it is due to its ability to "attract" any residues... and hold them there, especially if humidity or oil are present. In itself, it is NOT abrasive, being just a hygroscopic solvent.
Normal use: Water Dispersant (hence the name, recipe No. 40). It is also not a high wear lubricant, can only be used on light service. The best description is: very good short term lubricant, but so is water...

[BILL OXIDEAN]

Stick a roll of paper towels in the trunk of the car you go to the pond with.
THOROUGHLY dry the deck and hatch before re-taping

Sounds simple, but how many of us forget towels when we jaunt to the pond?

I find paper towels and napkins better than using cloth towels.
re-using cloth leaves a slight ammount of moisture on the mating surface deeming the tape useless in a 35+mph crash

[Doug Smock]

Whatever you use for floatation, consider using an adhesive to keep it in the hull in the event of a catostrophic hull failure. (It happens)
Not much worse than having your floatation simply mark the spot where your boat went down.

My .02
Doug

[BILL OXIDEAN]

Whatever you use for floatation, consider using an adhesive to keep it in the hull in the event of a catostrophic hull failure. (It happens)
Not much worse than having your floatation simply mark the spot where your boat went down.

My .02
Doug

Great point, and on that note, don't use double sided foam tape to secure it, it can have a tendancy to come undone when wet I used small dabs of epoxy

[Doug Smock]

Great point, and on that note, don't use double sided foam tape to secure it, it can have a tendancy to come undone when wet I used small dabs of epoxy

Gorilla Glue works well also, fills small gaps and is tough as nails!

[FloatDaBoat]

These photos are of what Great Stuff spray insulation foam looks like applied to the sponson tips of my cat during construction. It will stick to anything, so be sure to mask any areas where you don’t want it to. A word of caution: it continues to expand for days after being sprayed in. I had to sand it down three days running before attaching the deck, & it still expanded a little more - - causing a slight bulge in the deck. I wouldn’t recommend using it in an already enclosed space, as the hull/deck seams might split wide open.

[befu]

Interesting

that is interesting about the long term shrinkage, thank you for pointing that out. i have used it in the past but never filling a hull. I was thinking about it, but will have to do some experimenting now. It is full of air, wonder if it is temperature and pressure sensitive?

Like many, I have damaged hulls by using the spray expanding foam in my early days. I still do use it at times, but you have to use it correctly. If you use spray foam, do not fill the cavity. I make sure that it does not fill the space from the bottom to the deck once expanded. it works fine, maybe even adding it in multiple segments. It helps to be building a house and use the remnants of a can from weather proofing.

The can spray foam will also shrink. I filled a hatch with it once, let it set for a few days and then trimmed it flush with the bottom of the hatch. next day, the old flat foam surface was concave! Didn't see that one coming.

Thanks for the knowledge fluid!

Brian

I strongly recommend not using the NHP two-part expanding foam. I used in in a very stout 'glass sport hydro and it stiffened up the hull even more, acting as a structural part of the boat. But about a year later it started to shrink, pulling the deck down in a wavy pattern over 1/8" - so much that the hatch no longer fit. I had to cut it away from the deck, fortunately the deck popped back up most of the way. I prefer pool noodles anyway, that was an experiment - which failed.



Abrasive - without solids? An odd property which I've never seen mentioned before.


.

[Chop]

These photos are of what Great Stuff spray insulation foam looks like applied to the sponson tips of my cat during construction. It will stick to anything, so be sure to mask any areas where you don’t want it to. A word of caution: it continues to expand for days after being sprayed in. I had to sand it down three days running before attaching the deck, & it still expanded a little more - - causing a slight bulge in the deck. I wouldn’t recommend using it in an already enclosed space, as the hull/deck seams might split wide open.

An alternative to "masking" is to spray or wipe a non-stick cooking spray to the surfaces that you don't want the foam to stick to. Then it is a simple matter of trimming the excess material away.

As an afterthought... You could just spray the entire insides with the cooking spray. You would have flotation molded to the inside of your hull. It might alleviate the "shrinkage" issue too (I hate that!).

[crabstick]

for boats that are "bouyancy challenged" such as some riggers where there is not enough space for the flotation needed to keep the boat bouyant I have thought of using a device such as :

http://www.marine-super-store.com/posit/shop/index.php?selectedpartno=99197216

They self inflate and can support 1kg, a couple of those might do the trick Embedded in the deck.

Theres this one also

http://www.shopwiki.com/Key+Buoy,+Self-inflating+Key+Ring

There is also another boaties keyring that has a cork and a huge length of braid in it, when it hits the water the keyring sinks, but the cork ejects and leaves a trail of braid to the ring which you simply pull the keyring back...

[egneg]

for boats that are "bouyancy challenged" such as some riggers where there is not enough space for the flotation needed to keep the boat bouyant I have thought of using a device such as :

http://www.marine-super-store.com/posit/shop/index.php?selectedpartno=99197216

They self inflate and can support 1kg, a couple of those might do the trick Embedded in the deck.

Theres this one also

http://www.shopwiki.com/Key+Buoy,+Self-inflating+Key+Ring

There is also another boaties keyring that has a cork and a huge length of braid in it, when it hits the water the keyring sinks, but the cork ejects and leaves a trail of braid to the ring which you simply pull the keyring back...

Starting to look like a 007 movie with all the gadgets.