Alternative to a widebeam?

[Alan de Enfield]

2 minutes ago, Tracy D'arth said:

I think the reaction of PVC and polystyrene causing problems is an canal-side myth.

Seen hundreds of places where they have been in contact for decades without any degradation of the PVC, just the polystyrene erroded.

 

Having worked for many years as an electric cable designer, and actually written many of the Specifications for the likes of the NCB, British Standards, British Aerospace etc I can assure you, it is not a canal-side myth.

 

We had huge problems with standard PVC wires and cables going brittle as the plasticisers leach out, and, when subject to vibration or movement the insulation would fall off and the bare conductors short-out.

 

Pictures of PVC cable in a domestic loft in the early stages of attack by Polystyrene.

 

You'll find plenty about it if you search online.

 

1st google hit :

 

However, if expanded polystyrene is in intimate contact with PVC sheathed cables, over time a chemical reaction can draw out the sheath plasticiser to form a sticky layer on the outside of the cable.

 

 

 

 

[MtB]

5 minutes ago, Tracy D'arth said:

I think the reaction of PVC and polystyrene causing problems is an canal-side myth.

 

 

It's not a myth, I see the effect several times a month on one of the brands of boilers I fix, but I've never thought to photograph it. 

 

The boiler has a plate heat exchanger insulated with a one-piece expanded polystyrene moulding, and at the factory during manufacture, a sensor cable (made from standard 3 core insulated flex) is draped over it. When I get called to fix a breakdown this sensor cable has usually burrowed itself a deep channel into the polystyrene, just as you'd expect had the cable been really hot at some point. But it can't have been. 

 

On pulling the cable out of the channel it made for itself, the cable insulation appears perfect and unaffected, just the polystyrene is damaged. 

 

I'll take a photo next time I see it. 

[David Mack]

3 minutes ago, MtB said:

On pulling the cable out of the channel it made for itself, the cable insulation appears perfect and unaffected, just the polystyrene is damaged. 

Presumably in these cases sufficient plasticiser remains in the pvc cable sheath for it to remain flexible. But that won't always be the case.

[LadyG]

3 hours ago, Tony Brooks said:

 

That is definitely a mater of opinion.  You may like the boy racer styling of modern production craft, but I do not. I very much prefer function over form and the OP wants a one level boat with internal space for long term living. I doubt Naughty Cal  and the like comes close to his requirements.

 

As I said, I don't think the cabin sides are lined, or if they are it is just glued on "Fablon" material. Some had a sprayed on textured and flecked paint. The  plastic film will be destroyed in the remove so he can batten to take insulation and a new lining. I also think much of the cupboards etc. may well be standard 500 mm units so may well just pull out after a few fixings have been removed, but he needs to check all this.

 

I do not think you have the experience and knowledge of such boats to comment on any basis other than your personal taste.

I'm not telling OP to buy a Naughty Cal, and agree the one he likes, and surveyed, and likely to purchase is practical, suited to his purposes, but a long, long way from a luxury yacht.  

[Alan de Enfield]

5 minutes ago, LadyG said:

I'm not telling OP to buy a Naughty Cal, and agree the one he likes, and surveyed, and likely to purchase is practical, suited to his purposes, but a long, long way from a luxury yacht.  

 

But remember the boat you bought is a long way from your original 'laid down, red lines, specification'.

 

As, I'm sure,  are most of the boats owned by forumites.

[LadyG]

1 minute ago, Alan de Enfield said:

 

But remember the boat you bought is a long way from your original 'laid down, red lines, specification'.

 

As, I'm sure,  are most of the boats owned by forumites.

The boat I bought has the most important criteria, namely by a good builder and in good condition. It was not far off being suited to cc. 

I have spent time and money on cleaning it up, but it's never going to be top of the range, one reason being that I can't find anyone to do a week's work fitting out to a  high spec standard, so I have to do it myself, limited skills and motivation.

The re-sale value of the boat is limited by it's overall specification.

 

[Tracy D'arth]

1 hour ago, MtB said:

 

 

It's not a myth, I see the effect several times a month on one of the brands of boilers I fix, but I've never thought to photograph it. 

 

The boiler has a plate heat exchanger insulated with a one-piece expanded polystyrene moulding, and at the factory during manufacture, a sensor cable (made from standard 3 core insulated flex) is draped over it. When I get called to fix a breakdown this sensor cable has usually burrowed itself a deep channel into the polystyrene, just as you'd expect had the cable been really hot at some point. But it can't have been. 

 

On pulling the cable out of the channel it made for itself, the cable insulation appears perfect and unaffected, just the polystyrene is damaged. 

 

I'll take a photo next time I see it. 

That is my experience too.

 

Does it matter if the outer sheath goes sticky? I have never seen any embrittlement of the conductor insulation.

[Alan de Enfield]

Just now, Tracy D'arth said:

I have never seen any embrittlement of the conductor insulation.

 

 

I have,

We used to supply the record player and TV market with the mains cables, the cabinets of the Record player and TV were polystyrene (no , not the expanded white stuff, but still polystyrene) where the cables passed thru the cabinets the PVC went brittle and the condustors shorted out. We develope a non-migratory PVC compound with BP Plastics and that cured the problem. 

The problem was the additional cost - longer term they decided to use a Nylon bush to run the cable thru the cabinet and that acted as an 'insulator / separator/ between the Polystyrene and the PVC.

[blackrose]

4 hours ago, Tracy D'arth said:

That is my experience too.

 

Does it matter if the outer sheath goes sticky? I have never seen any embrittlement of the conductor insulation.

 

If the cable insulation becomes sticky it sounds like plasticiser leaching out so eventually that would lead to embrittlement. I don't think it's canal side myth, it's a well researched phenomenon and in the technical literature. 

[Bod]

26 minutes ago, blackrose said:

 

If the cable insulation becomes sticky it sounds like plasticiser leaching out so eventually that would lead to embrittlement. I don't think it's canal side myth, it's a well researched phenomenon and in the technical literature. 

I thought this leaching had been discovered decades ago, and as a result the PVC. cable insulation had been changed, industry wide to prevent this.

Not to say that affected cables won't be found now or that penny pinching manufacturers will use old receipts for PVC. insulation.

 

Bod

[blackrose]

3 hours ago, Bod said:

I thought this leaching had been discovered decades ago, and as a result the PVC. cable insulation had been changed, industry wide to prevent this.

 

 

I didn't know about that. Where did that information come from? 

[Alan de Enfield]

27 minutes ago, blackrose said:

 

I didn't know about that. Where did that information come from? 

 

From my experience the addition of the non-migratory compound affected other charateristics, such as heat resistance and flexibility such that the cable would not meet 'other' standard requirements.

Maybe there has been a new compound developed which retains all of the original characteristics whilst offering the non-migratory resistance.

 

All I can find on Google is that an Australian cable company have 'special' insulated cables for use where polystyrene may come in contact with them they state that :

 

Overview

PVC insulating and sheath compounds for cables are formulated to give excellent mechanical and electrical properties for the duration of service life. Modern PVC plastic formulations utilize resins, plasticizers, antioxidants, stabilizers and fillers to achieve characteristics such as flexibility, thermal stability and mechanical and electrical protection in accordance with Australian cable standards.

PVC compounds are thermally stable for the operating temperatures encountered in typical installation conditions, when installed in accordance with AS/NZS 3000.

Discussion

Certain groups of plasticizers used in PVC compounds are soluble in aromatic polymers and petroleum based products. When in direct contact with such materials (e.g. styrene, Styrofoam, polyurethane and bituminized papers) PVC compounds can demonstrate plasticizer migration. This migration can result in;

1. The loss of physical and electrical protection afforded by the insulation and sheath components of the cable, leading to potentially dangerous situations.
2. Degradation of the material which the cable is in contact with.

The breakdown effect of migration is mainly long term but can be exacerbated by the size of the surface contact area and elevated temperatures such as found in roof sheeting.

Recommended installation practices

It is recommended that installers ensure general market PVC insulated and sheathed electrical cables be installed in such a manner that they do not come in to direct contact with aromatic polymers (e.g. styrene, Styrofoam and polyurethane), bituminized papers and waterproofing. Cables should be installed in suitable conduits or protected by the use of polyester or polypropylene separation tapes. Alternative PVC cables utilizing non- migratory plasticizers are available, installers should ensure any such cables sourced can demonstrate suitable long term test results to substantiate performance.

 

 

From a UK  building forum :

 

How do I install cables without non migratory plasticiser?

When using cables without non migratory plasticiser it is recommended that there be no direct contact between the cable and the polystyrene, this can be achieved by installing in a suitable conduit, leaving an air gap or using a polyethylene or polypropylene tape between the cable and the insulation.

Sealing around electric cable - Electrics - Other

forum.buildhub.org.uk/topic/1071-sealing-around-electric …

 

But - of course it could all be a 'canal side myth' !!

Edited June 9, 2022 by Alan de Enfield

[Bod]

I think it came to light, when the polystyrene loft insulation  was all the rage, the bags of beads you poured all over the loft floor.

Fires were caused by the PVC insulation degrading in contact with the beads. 

 

Bod.

 

[Alan de Enfield]

59 minutes ago, Bod said:

I think it came to light, when the polystyrene loft insulation  was all the rage, the bags of beads you poured all over the loft floor.

Fires were caused by the PVC insulation degrading in contact with the beads. 

 

Bod.

 

 

 

 

We know about that, but were wondering what evidence you had that all PVC cable are now manufactured using non-migratory PVC.

 

 

 

5 hours ago, Bod said:

.....and as a result the PVC. cable insulation had been changed, industry wide to prevent this.

 

[Bod]

I must admit to working from memory with this.  It would have been the Fire brigades who would have first raised concerns, owing to loft fires, including polystyrene insulation and electricity.

This topic may have come up during the 16th Edition I.E.E, wiring regs in 2000, or P.A.T course in 2009.

 

Bod

[Tacet]

 

The Institution of Engineering and Technology link

It is reported that expanded polystyrene is most affected, but it can also occur with ABS or polycarbonate. It is stated by some manufacturers that modern PVC sheath compounds no longer react with expanded polystyrene, but if PVC sheathed cables are expected to be in contact with expanded polystyrene or other similar materials the advice of the cable manufacturer should be sought for the design

[Alan de Enfield]

21 minutes ago, Bod said:

I must admit to working from memory with this.  It would have been the Fire brigades who would have first raised concerns, owing to loft fires, including polystyrene insulation and electricity.

This topic may have come up during the 16th Edition I.E.E, wiring regs in 2000, or P.A.T course in 2009.

 

Bod

 

OK.

 

I could well imagine that IEE regs demanded that Non-Migratory PVC (or was wrapped or sleeved) could be demanded for applications where there was the possibility of contact with styrenes etc, but to demand that ALL PVC cable should be made that way would seem to be excessive, and add to the costs of (say) 99% of installations.

 

 

9 minutes ago, Tacet said:

It is stated by some manufacturers that modern PVC sheath compounds no longer react with expanded polystyrene,

 

 

 

Maybe 'some' manufacturers have adopted it as a standard to minimise stock holding.

 

 

Historically wire and cables were made to meet UL, (Underwriters Laboratory USA) or CSA,(Canadian Standards Association)  or BS (British Standards) requirements (depending on the customer requirements) later developments allowed for wires to be made that met all three standards and are what we now call "Tri-Rated" as in complying with all three standards. Minimising stock holding and manufacturing complexity.

 

 

 

Edited June 10, 2022 by Alan de Enfield

[David Mack]

35 minutes ago, Bod said:

I must admit to working from memory with this.  It would have been the Fire brigades who would have first raised concerns, owing to loft fires, including polystyrene insulation and electricity.

This topic may have come up during the 16th Edition I.E.E, wiring regs in 2000, or P.A.T course in 2009.

 

Bod

It's been known about longer than that. Graham Booth's Narrowboat Builder's Book, published in 1993, says of shell insulation:

"Polystyrene is very easy to handle and not expensive to buy. However, in 1990, surveyors discovered that, when in contact with the PVC coating over electric wire, it causes that coating to become brittle with consequent risk of shorting to the steel shell. Elementary discipline in keeping the materials apart overcomes the problem."

[cuthound]

On 08/06/2022 at 16:47, Tracy D'arth said:

Could someone tell me what anti-fouling is for on an inland boat in freshwater in congested London where it will never move?

 

The OP mentioned anti-fowling. I presumed it stops the ducks pecking at the weed on the waterline...  😂🤣

[cuthound]

On 08/06/2022 at 17:40, Noviceboata said:

As mentioned earlier, that stove in the picture is a diesel heater (not sure if it doubles as a solid fuel stove) Im not even sure is it works, I guess by the look of it, it is a very old diesel heater and needs replacing

 

Are you sure? Whilst Howarth Heating  did make diesel drip versions of solid fuel stoves, there seems to be ash in the hearth of yours and diesel drip stoves don't produce grey ash. Also they have a fuel regulator which usually has a long rod with a ball on it to control it and yours doesn't. Finally they have a flame failure thermocouple that must be accessible in order to light the stove and your stove seems to boxes in to allow access to that.

[Tony Brooks]

Also, it looks like a wood board based "hearth" and as the stove is not stood on legs I think there is a fair chance that it is not approved for mounting on a combustible base.

[Noviceboata]

1 hour ago, cuthound said:

 

Are you sure? Whilst Howarth Heating  did make diesel drip versions of solid fuel stoves, there seems to be ash in the hearth of yours and diesel drip stoves don't produce grey ash. Also they have a fuel regulator which usually has a long rod with a ball on it to control it and yours doesn't. Finally they have a flame failure thermocouple that must be accessible in order to light the stove and your stove seems to boxes in to allow access to that.

Its definately a diesel heater as i saw the deisel drip feed at the back

[cuthound]

5 minutes ago, Noviceboata said:

Its definately a diesel heater as i saw the deisel drip feed at the back

 

If it is a diesel drip heater, then it will get as hot as a solid fuel stove. They are reliable if kept clean and properly set up. You will need to learn how to service it yourself as very few boatyards or boat technicians understand them. There is a Refleks Stoves User group on Facebook which very useful, even if you have a different make, because they all operate in the same way.

 

If it is capable of heating your hot water it will have water pipes entering and leaving it and a coil of pipes inside around the burner pot.

 

The main issue with diesel stoves now is the cost of diesel, but solid fuel is no longer that cheap either and both are currently a lot cheaper than gas for heating boats.

[Noviceboata]

6 minutes ago, cuthound said:

 

 There is a Refleks Stoves User group on Facebook which very useful, even if you have a different make, because they all operate in the same way.

 

Thanks for that, I will look into it. I love those reflex stoves, will definately get one when i make the final upgrade

[MtB]

6 hours ago, Noviceboata said:

Its definately a diesel heater as i saw the deisel drip feed at the back

 

 

In which case it will cost you about a pound an hour in fuel to run it, I suspect. Can you afford that ok?