Inject foam into hull of older boat - Worth doing ?

 Hi guys,

 

I have just purchased an older fibreglass boat (swiftcraft sea hawk). I have a few minor jobs that I am planning to get a fibreglasser conduct.

 

It has been suggested that I get the fibreglasser to drill core holes around the floor and inject foam into the bilge area to provide positive bouancy, better ride etc. From my searching I can only assume it would be a closed cell foam but I will need to confirm if this can be injected and if this is what is actually used...

 

Either way I have been told that it is not worth doing/worth the money as the swiftcraft are solidly built and the foam will only end up absorbing water, get heavy and promote rotting of the stringers etc.

But from what I read - if it is closed cell foam - then it won't absorb any water.

 

Can anyone who has had this same job done provide some feedback on it ? Is it worth doing to ensure safety and improve the ride or is there really not much point ?

 

Thanks !


carnarvonite's picture

Posts: 8622

Date Joined: 24/07/07

Why

Sat, 2017-01-14 06:15

If the boat hull is sound why bother.

It isn't going to provide a better ride and will only burn a hole in you pocket and add extra weight to the boat.

The only advantage is if you hit something then its going to take longer for your boat to sink

Swompa's picture

Posts: 3757

Date Joined: 14/10/12

 My father and I did it to

Sat, 2017-01-14 06:17

 My father and I did it to two boats we still currently own. It is essentially the same as the expandable foam you get in Bunnings, but it comes in part a and part b tins.

Yes, it adds weight, but more importantly it stiffens up the hollow under the deck and fills the void thus preventing any water ingress in the case of a hull breach.

I used the same product when making markers buoys and when they got damaged they slowly filled with water and Sunk.

Weather or not it is worth it is up to you. The fact that water ingress into a holed hull would be minimal is the seller for me and why we did it, 15 odd years ago...

 

Posts: 1317

Date Joined: 05/05/06

My old tub doesnt have

Sat, 2017-01-14 08:42

My old tub doesnt have flotation and I would like it for some peace of mind but at the moment im just filling under the deck with 2 stroke oil containers, gotta be better than nothing!

If you got the cash and the time id say do it.

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Bend over

just dhu it's picture

Posts: 1081

Date Joined: 14/05/09

Expansion

Tue, 2017-01-17 06:23

 just be mindfull of the expansion of the foam.  once you pour the mix in you cannot control the expansion which can be powerfull and expand in the wrong direction if too much is added and damage your boat

Jackalchub's picture

Posts: 593

Date Joined: 10/03/12

 Will the foam reduce noise

Tue, 2017-01-17 06:40

 Will the foam reduce noise while travelling? 

spook's picture

Posts: 325

Date Joined: 15/02/10

I just fixed a small crack in

Tue, 2017-01-17 06:51

I just fixed a small crack in my mates hull, couldnt be done if it was filled with foam. Just a thought. Why not use those cheap pool noodles?

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Haunted by water

Swompa's picture

Posts: 3757

Date Joined: 14/10/12

 They break down and provide

Thu, 2017-01-19 20:31

 They break down and provide no additional strength for weight

Posts: 140

Date Joined: 10/02/11

I foam filled my hull when I

Fri, 2017-01-20 11:18

I foam filled my hull when I got the floor replaced. Was a little quieter underway, I didn't notice any difference in the handling.

I mainly got it for piece of mind when out wide

Francis's picture

Posts: 326

Date Joined: 17/06/08

Urgh decisions

Sun, 2017-01-22 12:25

 Thanks for the responses - I've continued to do research and it seems that you need 1 cubic meter of foam to provide positive bouancy to a 1 ton vessel. The boat I just purchased is a 5m swiftcraft so I think it would deffinately provide the positive bouancy and the peace of mind.

 

I get the impression that the only foam that is truly water resistant is the green coolite sheets.  So I'm a bit worried that if the injected foam does hold water then it might encourage rot etc. I'll talk to the fibreglasser a bit more about the qualities of the foam when i get back from my work trip. 

 

I guess I need to decide if the $1500+ dollars is really worth it for a boat I picked up for 9k... if it made the boat unsinkable and would not encourage rot - then I think the answer might be yes.

The added benefit of quieting the ride is a bonus but I am interested to read from Gray that there was no difference to the handling.

 

I am also told that the older boats like baron's and swiftcrafts are super solid - really thick fibreglass - so it would be no different to hitting an object with a plate boat. Not sure how valid that is tho...

 

Decisions !

 

 

carnarvonite's picture

Posts: 8622

Date Joined: 24/07/07

Above deck

Sun, 2017-01-22 19:11

If you are really worried about sinking then give thought to fitting polystyrene sheeting from the deck up under the gunnels where the storage pockets are and glass it in. 100mm thick sheets are available and these will bend enough to follow the curve on the hull.

Posts: 27

Date Joined: 21/04/13

Collar

Tue, 2017-02-21 21:48

I put a foam collar around my 5m ali runabout to aid stability. Love it, works a treat.