Spray foam

[Manxcat54]

Would it be OK to spray foam the whole of the boat, leaving wiring inside flexible conduit, or do you have to re-wire the lot after spray foam? also whilst on here, at the bow end under the steps at the door, there is a space where the water pump sits, and the water tank is somewhere up there, I for one am sure that my large frame isn't going to fit up that hole for cleaning/painting, has anyone else been confronted with this, or should I try to find a chimney sweeps help and shove him up there? 

[Jen-in-Wellies]

Can the water pump be easily reached? They do break down and need access. If you live aboard, they can be considered a consumable and need replacement every four, or five years. For a leisure boat, it is still a consideration, as any pre-pump mesh filters need access for cleaning.

[Tony Brooks]

58 minutes ago, Manxcat54 said:

Would it be OK to spray foam the whole of the boat, leaving wiring inside flexible conduit, or do you have to re-wire the lot after spray foam? also whilst on here, at the bow end under the steps at the door, there is a space where the water pump sits, and the water tank is somewhere up there, I for one am sure that my large frame isn't going to fit up that hole for cleaning/painting, has anyone else been confronted with this, or should I try to find a chimney sweeps help and shove him up there? 

 

Before you do that, work out how you will get access to add circuits and/or repair circuit faults.

[Jen-in-Wellies]

My boat has wiring installed post spray foaming. Most running in an under gunwale wooden conduit, so accessible for fault finding and additions. Wires from the conduit to ceiling downlights are between wood lining and sprayfoam, so not as accessible, but possible if required. Some boats have a central ceiling conduit, with removable panels, that make subsequent work on ceiling lights much easier.

[Tony Brooks]

I suppose my attitude to this is dictated by my hie boat fitting out experience, where if things were not readily accessible it would cause problems for me later on, whereas with private boat fitting any problems only affect the customer AFTER the builder has been paid.

 

Apart from the locations for wiring and services that Jen suggests, you can also run them behind angled (L) trims where the cabin side meets the roof, or the hull lining meets the floor.

[ditchcrawler]

I suppose to spray over them in conduit is not much different from buying a wiring loom in that you are stuck with the termination locations, at least with conduit you can thread more wires through 

[David Mack]

If your wiring is already in flexible conduit, then sprayfoaming it in is probably OK as long as all the terminal/junction boxes remain accessible. Any additional wiring added later can then be threaded into the conduit or wired between the sprayfoam and the cabin lining.

But if there isn't any conduit at present it would be no more work and a better job to rewire after sprayfoaming.

 

Edited February 9 by David Mack

[Martin Nicholas]

You need an even coating of foam as possible. If your existing conduit is agasinst the steel this won't be possible and you can then get condensation within the conduit like I do.

 

You also need to make sure that there can be no ingress of foam into the conduit. That will make cabling impossible to maintain and it could overheat.

[Alan de Enfield]

2 minutes ago, David Mack said:

Any additional wiring added later can then be threaded into the conduit or wired between the sprayfoam and the cabin lining.

 

But - if using a cinduit without a removable lid -  it is advisable to pull a couple of pull cords thru the conduit - trying to poke a wire down a rats-nest of 'old' cables is not the easiest job.

[Manxcat54]

6 hours ago, Jen-in-Wellies said:

Can the water pump be easily reached? They do break down and need access. If you live aboard, they can be considered a consumable and need replacement every four, or five years. For a leisure boat, it is still a consideration, as any pre-pump mesh filters need access for cleaning.

It looks impossible to reach, I think I shall move it, and I am sure you should have an expansion tank in line with it plus other items such as stops and filters, it's probably going in the skip.

[Jen-in-Wellies]

21 minutes ago, Manxcat54 said:

It looks impossible to reach, I think I shall move it, and I am sure you should have an expansion tank in line with it plus other items such as stops and filters, it's probably going in the skip.

A good idea to move it to where it is accessible. I have my pump about 5m from the water tank. Accumulator in line, on the downstream side, but it can go any where in the cold water system, so put it somewhere easy to reach for pressure checking and pumping up. If there is a non-return valve before the calorifier, assuming you have a cauliflower, then that should have an expansion tank too. Again, site for easy access.

[ditchcrawler]

I had a friend with a Braidbar boat with the water pump tucked under there, it froze up while they were living onboard because the living area was so well insulated