Vintage Inboard Cruisers to Centre Console Conversion

[gazza2006au]

Yeah im now thinking of totally filling my back corner spaces with foam theres gotta be atlease 1/4m3 on each side

[Mopheus]

Yeah im now thinking of totally filling my back corner spaces with foam theres gotta be atlease 1/4m3 on each side

That's what you need to do. Fill the floor before fitting the deck (no brainer) then jam as much as you can in unused space under the gunwales, either side of the well, etc. See how far that gets you against your target and then get creative if needed at the end to achieve the balance.

You don't want to put it all under the floor Gazza.

You do though - otherwise it's an air void that can fill with water if cracked, leading to huge loss of buoyancy. It's not ideal compared with having it all up high but you simply can't fit in enough higher-level flotation to most older boats to achieve positive buoyancy without the contribution from the hull void.

Level flotation in an old boat is a bit of a pipe dream; having the tub turn belly up but not disappear into the depths is the more realistic aim.

[gazza2006au]

Hey Moph are u able to calculate the bouyancy of 166,000cm3 if the foam weighs 85kg/m3

I found some 85kg a cubic meter from the same seller with yhe 22kg a cubic meter is it safe to think the higher densoty foam provides more floatation?

[billfisher]

Originally Posted by billfisher
You don't want to put it all under the floor Gazza.



"You do though - otherwise it's an air void that can fill with water if cracked, leading to huge loss of buoyancy. It's not ideal compared with having it all up high but you simply can't fit in enough higher-level flotation to most older boats to achieve positive buoyancy without the contribution from the hull void.

Level flotation in an old boat is a bit of a pipe dream; having the tub turn belly up but not disappear into the depths is the more realistic aim".

That's not what I said. I said you don't want to put all the foam under the floor (even if you could). And if you have done the calculation and can get all the foam required up high it doesn't matter if the hull is holed - the boat will still float. And importantly likely to be upright. This puts you in a far better position than trying to cling to an upturned boat.

PS: I am fitting level floatation into my 5.4 m glass boat and it looks like I will be able to get all the required foam in above floor level.

[Mopheus]

PS: I am fitting level floatation into my 5.4 m glass boat and it looks like I will be able to get all the required foam in above floor level.

That's sensational. A 'life ring' of flotation foam around the boat at gunwale level is close to ideal (topped only by the Boston Whaler method that keeps the powerhead above water too); just often difficult to achieve all the buoyancy you need at that level.

I (mis)read your post as saying not to fill the floor with foam. Apologies if that wasn't your intent. I just didn't want Gazza to not fully fill the floor while he has it open. If he's not able to achieve positive buoyancy using above-deck foam, then it could be that foam-filled floor that saves him. Better to have a boat that floats upside down than one that has an inadequate buoyancy ring at gunwale level, holes the hull and ends up sinking.

If you look back at #2501 you'll see that I'm in total agreement re keeping flotation as high as possible though.

[gazza2006au]

I done a little web surfing after u guys mentioned the vic has a floatation information i found the website

[gazza2006au]

Im just out here in the boat at 10:40pm warming up the hot glue gun i just made a front floor template

Got flys going like crazy under this led strip flying into my "wig"

[gazza2006au]

A bit better picture each piece is hot glued there are 2 floor pieces there

That anchor wall i cut into that in the demo it was all solid and hard to remove i'll sort that out once the floors down

[gazza2006au]

As for the floatation foam my gunnels front half should hold 200x60mm x long, my rear half should hold 200x 120mm x long so i have plenty of space for bouyancy

[billfisher]

reposted see below

[billfisher]

That's sensational. A 'life ring' of flotation foam around the boat at gunwale level is close to ideal (topped only by the Boston Whaler method that keeps the powerhead above water too); just often difficult to achieve all the buoyancy you need at that level.

I (mis)read your post as saying not to fill the floor with foam. Apologies if that wasn't your intent. I just didn't want Gazza to not fully fill the floor while he has it open. If he's not able to achieve positive buoyancy using above-deck foam, then it could be that foam-filled floor that saves him. Better to have a boat that floats upside down than one that has an inadequate buoyancy ring at gunwale level, holes the hull and ends up sinking.

If you look back at #2501 you'll see that I'm in total agreement re keeping flotation as high as possible though.

Thanks for that - it all makes sense now. Actually I have some floatation under the floor to from when the boat was made. I left this out of the calculation. They poured in 2 pack polyurethane foam. Some of it has been removed for repairs. It can be handy for filling up voids without having to rip up floors etc. But it can cause problems such as waterlogging and you have to be very careful as it's expansion properties can cause damage if there is too much poured in with nowhere for it to go.

[gazza2006au]

I twisted my ankle last night just woke up in the worse pain its almost as bad as the spine lifting that mercury powerhead damn it hurts could barely hobble to the toilet

Bill i read that u need to be careful with the 2 part foam and its expansion busting open the boat i have seen online so many people gluing there floors down and pouring the foam down through little holes its crazy after the amount of work it takes to rebuild a boat

[gazza2006au]

Ankle feels alot worse than i tgought 2 days in now in throbbing pain a good 7 out of 10 drops to a 6 with nurofen sure its just a twisted ankle or pulled stretched muscle .... it hurts

Since i cant do anything boat related i will order the foam, i couldnt find anything relating weight of foams if 85kgm3 was better than 22kgm3 stuff all google came up with was to use 35kg3m weight foam but cant find that

[Mopheus]

i couldnt find anything relating weight of foams if 85kgm3 was better than 22kgm3 stuff all google came up with was to use 35kg3m weight foam but cant find that

The lower the density of the foam, the better - provided that it still ticks all the boxes in terms of workability, flammability, resistance to waterlogging, etc. The 85kg/m3 foam is much denser and will provide less flotation per m3 so you'd need more of it. The 22kg/m3 foam will provide more flotation per m3 but its structure will also be more open, so likely easier to damage/dent and possibly water permeable [check].

Avoid polystyrene (fuel melts it). Polyurethane sheet can wear with abrasion so wrapping in plastic before fitting is recommended, which is a hassle. Polyethylene seems to be the best fit as it doesn't abrade, resists waterlogging and is fuel stable. Note that the cheaper expanded polyethylene sheet (EPE) is only moisture resistant, not waterproof, and can absorb water in the longer term - so if you can, save your pennies and buy impermeable cross-linked polyethylene (PE or EVA).

The links below show examples of the three:

EPE 18-25kg/m3 $550/m3: https://www.foamsales.com.au/product...nt=35932206785
EVA 40kg/m3 $1900/m3: https://www.foamsales.com.au/product...nt=10852885697
PE 30kg/m3 $1380/m3: https://www.foamsales.com.au/product...28873585229872

I'd be going with PE - better than EPE; lighter and cheaper than EVA, giving up only some elasticity and recovery after long-term compression by comparison; both things that you don't really need for a buoyancy install. The Tassie MAST installs used Microlen PE; seems its available from Jenkins Rubber but they don't have pricing on their website (have to request a quote).

If the budget only stretches to EPE then be aware that keeping it dry is critical. If you have a leaky bung and the foam swims in water regularly, the EPE will eventually absorb it leading to waterlogged foam issues.

[gazza2006au]

Moph i will use this shop as they do afterpay https://foamandrubber.com.au/collect...30337422786660 it sayson here the PE foam is water resistant will this foam still be waterproof being PE?