Beneteau heads floor

[mrplastic]

Hi all,

The floor in the heads on my Beneteau 331 makes a cracking noise when stood on. It's GRP and not cracked but there is obviously a gap between it and the hull and it's flexing. My initial thoughts were to drill a hole and squirt some expanding foam inside and then use a plastic cap to seal the hole but unsure what else may be under there.

There does not appear to be any access to the void so I'm wondering if anyone has any other/better ideas on how to cure this. Maybe another 331 owner could let me know if it's typical or confined to my boat!

Ta very!

 

[Stork_III]

There may be access from inside the cupboard, there is on my HR.

 

[mrplastic]

Thanks for that, I'll check it out

 

[cmedsailor]

There may be access from inside the cupboard, there is on my HR.

Yes there is some access in the Beneteau 361.

 

[30boat]

Whatever you do don't use expanding foam.It's not structuraly strong and soaks up water.What you're experiencing is the inner lining flexing.Apart from beefing it up with a few layers of glassfiber I don't see a better solution.You could lay a fiberglass panel say, 4mm thick,on a suitable waxed flat surface with white gelcoat down and then cut it to shape and glue it in place with epoxy or CT1.That'll look neat,need no finishing and do the job.

 

[shan]

Are you referring to single component, 2 component foam, closed cell or open cell foam? They are all quite different in structure and strength as well as properties. Some are impervious to water, some aren't and some have quite high tensile strengths and structural stability. The problem is most people don't know very much about polyurethane foams and lump them all into the category of open celled single component foam, which reacts to moisture.

 

[mrplastic]

Are you referring to single component, 2 component foam, closed cell or open cell foam? They are all quite different in structure and strength as well as properties. Some are impervious to water, some aren't and some have quite high tensile strengths and structural stability. The problem is most people don't know very much about polyurethane foams and lump them all into the category of open celled single component foam, which reacts to moisture.

I hadn't got that far, but yes I understand there are many variations. You obviously have some knowledge in this area so have you any recommendations?

 

[30boat]

Are you referring to single component, 2 component foam, closed cell or open cell foam? They are all quite different in structure and strength as well as properties. Some are impervious to water, some aren't and some have quite high tensile strengths and structural stability. The problem is most people don't know very much about polyurethane foams and lump them all into the category of open celled single component foam, which reacts to moisture.

I'm pretty sure the OP was thinking of the normal open cell variety.

 

[shan]

I hadn't got that far, but yes I understand there are many variations. You obviously have some knowledge in this area so have you any recommendations?

Yes, I have some experience with polyurethanes. Basically, I would rule out single components and open celled foams and before you decide how much you want to spend,you need to establish how big the gap is between the 2 layers. Realistically, anything less than 50mm and you are wasting your time with polyurethane foam because it is too narrow to successfully inject. It's also pretty expensive. In your position, I would take one of the previous poster's suggestions and stiffen up the floor with fibreglass. Perhaps,depending on access, you could even shove in some supporting battens between the 2 skins?

 

[mrplastic]

Yes, I have some experience with polyurethanes. Basically, I would rule out single components and open celled foams and before you decide how much you want to spend,you need to establish how big the gap is between the 2 layers. Realistically, anything less than 50mm and you are wasting your time with polyurethane foam because it is too narrow to successfully inject. It's also pretty expensive. In your position, I would take one of the previous poster's suggestions and stiffen up the floor with fibreglass. Perhaps,depending on access, you could even shove in some supporting battens between the 2 skins?

Ok thank you, I will consider my options. I have looked at access via the heads cupboard and the gap is very small, maybe 10 or 20mm at most so this will not be easy. Rather than build a new floor I may router out the existing panel and vacuum form a new custom floor panel insert (I own a large format Vacuum Forming & plastics fabrication company) so not as difficult or expensive for me as it could be....I will ponder

 

[shan]

That would be your best option. At 10mm to 20mm, you would not be able to inject much and anything you did, would have massive air pockets. Polyurethane foams are fabulous in the right applications. Unfortunately, this is not one of them.

 

[oldsaltoz]

The last time I had a creaking floor I simply drilled a small hole and inserted a mix or epoxy resin and Micro-fibres mixed to a consistency of tooth past, taking care to ensure no weight was on the area at the time.

After curing I cut a tiny countersink into the surface and filled to match the surrounding finish. Still invisible and no creaking after 5 years.

I also had a lift out panel that would rock when stepped on, I mixed up a batch (see above, and placed some glad wrap over it the replaced the panel and put gentle pressure on to get it seating properly. no prpblm sisne the panel is freee to lift out any time.

Good luck and fair winds.

 

[30boat]

The last time I had a creaking floor I simply drilled a small hole and inserted a mix or epoxy resin and Micro-fibres mixed to a consistency of tooth past, taking care to ensure no weight was on the area at the time.

After curing I cut a tiny countersink into the surface and filled to match the surrounding finish. Still invisible and no creaking after 5 years.

I also had a lift out panel that would rock when stepped on, I mixed up a batch (see above, and placed some glad wrap over it the replaced the panel and put gentle pressure on to get it seating properly. no prpblm sisne the panel is freee to lift out any time.

Good luck and fair winds.

Funny.Thats how I set the panels on my boat.Some gloops of epoxy filler under the floorboards(taped) and I got rid of the creaks.

 

[Border Terrier]

Don't bung up the access to the heads water sump pump.

I have cannibalised my heads drainage pipe and it now; with a suitable length of additional tube; allows water extraction from any part of the bilges.

How's that for a subject drift!?

 

[30boat]

Don't bung up the access to the heads water sump pump.

I have cannibalised my heads drainage pipe and it now; with a suitable length of additional tube; allows water extraction from any part of the bilges.

How's that for a subject drift!?

Not bad!