Liquid PVC insulation - Any good?

[Maluisarot]

The foam that covers the fuel tank inspection cover on our van has give very soft

On closer inspection, people walking from the cab to the back have worn some of the insulation off the cables in the looms that run under it.

There's not really any slack in the cables for a simple splice and rejoin with crimps or presoldered heat shrink but I've stumbled across a paint on PVC insulation.

Has anyone tried it or can anyone recommend another solution?

Cheers

 

[Lucky]

Can you not cut out the damaged section and replace with a longer piece, thereby giving the slack you need?

 

[Maluisarot]

Can you not cut out the damaged section and replace with a longer piece, thereby giving the slack you need?

Could do but there's 4 cables affected so 8 connections to make in confined space. Was hoping for something a bit more lazy

 

[Minxy]

That's a lot of wear! Do you keep baby elephants in your MH?

Before you do anything though get all the cr@p out of there as it will be abrasive then you can check the rest of the cabling too, then the below should ensure it is safe, although it could be fiddly to do just take your time:

• Make a patch use a long section of cable insulation which has a wider diameter than the original, cut it longer so it extends at least half an inch past each end of the cuts, then split it down its length and stick it on over the cabling to give it some protection, holding it in place with a couple of pieces of tape until it sticks solid.
• Remove the tape and check to make sure the patch is stuck and correctly and protecting the once exposed wiring
• Wrap it all well with a good quality insulation tape (not a £1 shop special!) - don't be tempted to do this before it's stuck solid otherwise it could get messy!

Afterwards you need to do something to prevent it happening again - the centre walkthrough is always squishy on PVCs (and many MHs too) so for ours I used to put some polystyrene or other type of padding between the cover and the base area underneath to support it, it made it much nicer to walk through with no risk of damage, oh I'd also put a rug or mat over it too to prevent more 'crud' getting under there.

 

[Jev88]

Pass through Wago connector? I am sure they come in 2, 3 4 and 5 channel versions.

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[Minxy]

Pass through Wago connector? I am sure they come in 2, 3 4 and 5 channel versions.

View attachment 484284

Nooooooooo ... having used them myself whilst they are great for many things the thought of the OP trying to cut the cables, push them in, clamp and then do the next one would definitely drive him nuts.

 

[Lenny HB]

Do what Hymer do as standard, cut it away and fit a lightweight plywood panel,

 

[Jays2]

Going to check mine now.
I agree it’s the sand that has helped wear down the insulation.
Also agree with the insulation tape, and maybe silicon over the top, that could provide a extra level of insulation?
Then check regularly, and vacuum out at each check.
Would not cut the cables and reconnect.
Keep it simple, first.

 

[autorouter]

Afterwards you need to do something to prevent it happening again - the centre walkthrough is always squishy on PVCs (and many MHs too) so for ours I used to put some polystyrene or other type of padding between the cover and the base area underneath to support it,

Not polystyrene - it makes PVC insulation brittle

 

[Minxy]

Not polystyrene - it makes PVC insulation brittle

Not on the wiring itself, just the plastic base well away from the wiring ... unless it can 'leach' chemicals?

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[autorouter]

Not on the wiring itself, just the plastic base well away from the wiring ... unless it can 'leach' chemicals?

It's only a problem if it makes contact with the wiring insulation.

 

[Gromett]

Can you not cut out the damaged section and replace with a longer piece, thereby giving the slack you need?

This would be my recommendation also. Do it right and do it once. Bodge it and you will probably have to redo it in a few months/years.

I would avoid using the solder type crimps, the type with the glue are good though. Especially in a footwell as they prevent the ingress of moisture which is a strong possibility in that location.
The solder types may make the wire brittle over time.

This is the type I would use not necessarily this one but similar. It gives a perfect seal around the cable preventing any ingress of moisture.

https://www.amazon.co.uk/Connectors-Waterproof-Electrical-Automotive-Electrapick/dp/B07GDHXN21?tag=mhf04-21

 

[eddie]

I agree with Gromett about adhesive lined heat shrink butt connectors, but make sure you use heat shrink butt connector crimping tool, not the standard crimping tool.

A standard crimping tool damages the heat shrink material in its jaws as the heat shrink material is much softer that the plastic or nylon used as and insulator on normal terminals

 

[deleted79651]

Pass through Wago connector? I am sure they come in 2, 3 4 and 5 channel versions.

View attachment 484284

Should be availabe from Screwfix or Toolstation in various sizes to suit the available space

Steve

 

[Manic]

You could wrap damaged wires with Self amalgamating tape and then fit a board as Lenny HB suggested

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[pwilmo]

Hi there, don't want to alarm you because all the techy advice on this post is brilliant and very helpful .. however, that damage to the wiring looks so like it's chewed by a mouse, it doesn't look like abrasive damamge to me. Pesky little varmits did similar damage in my previous motorhome, and they have perhaps been chomping on the foam used for the flooring support aswell, hence the sunken appearance.
I hope I am wrong and that is not the source of your problem, but it seems improbable to me that there would such abrasive damage caused by the flex in the flooring, especially to underneath wiring also.
Good luck with your repairs as there is lots of good solutions been suggested here.

 

[Lenny HB]

Hi there, don't want to alarm you because all the techy advice on this post is brilliant and very helpful .. however, that damage to the wiring looks so like it's chewed by a mouse, it doesn't look like abrasive damamge to me. Pesky little varmits did similar damage in my previous motorhome, and they have perhaps been chomping on the foam used for the flooring support aswell, hence the sunken appearance.
I hope I am wrong and that is not the source of your problem, but it seems improbable to me that there would such abrasive damage caused by the flex in the flooring, especially to underneath wiring also.
Good luck with your repairs as there is lots of good solutions been suggested here.

I've just had another look fairly certian you are right. For the damage on the green cable to occur by the floor moving, the floor would have to move back and forwards several inches.

 

[Bluemanc100]

The foam that covers the fuel tank inspection cover on our van has give very soft View attachment 484178

On closer inspection, people walking from the cab to the back have worn some of the insulation off the cables in the looms that run under it.

View attachment 484177

There's not really any slack in the cables for a simple splice and rejoin with crimps or presoldered heat shrink but I've stumbled across a paint on PVC insulation.

Has anyone tried it or can anyone recommend another solution?

Cheers

Have you been renting it out as a set for the Great British Bake Off?

 

[Maluisarot]

Thanks for all the replies and helpful suggestions.

I love wagos, and apparently so do Chausson: they use them to connect everything which is great for future maintenance. I think given the limited space they might be too bulky to use for this though

Any kind of tape will be a real PITA to pass around the cables and do a neat job with the floor, other cables and sub floor all getting in the way.

I did like the idea of the liquid PVC insulation and it looks a great product but at £15 a bottle I think I'll stick to slicing and some inline crimps. Can't wait for the fun and games to start with trying to get the crimping tool into that tight space


Definitely fitting a cover to stop the problem getting worse. We've got a nice thick carpet that covers the cab floor so I've gone for an aluminium plate to reinforce the area between the seats as looks not going to be important:

We've taken on the MH after 75k miles of someone else's wear so there certainly could have been a heard of elephants in there at some point

The problem definitely hasn't been caused by mice, no droppings or nibbled anything else. Plus the damaged cables are directly under the plastic latch that fiat design to hold the flap closed when the screw top is turned. My thoughts is the pressure on the cables every time it was stepped on, combined with vibration during transit has made this hard plastic part scrub away at the PVC insulation.

Reccomend anyone with a ducato base to have a look under here and maybe use some gaff tape to make sure the cables under there stay far forward enough they don't end up with similar damage further down the line.

Although I do know how pesky rodents can be in vehicles, once had an MGB a family of squirrels decided to make their home in and I only found out about them when one decided to start bouncing around over the dash halfway down the A38 somehwere near Burton

 

[EuroTrotters]

Pass through Wago connector? I am sure they come in 2, 3 4 and 5 channel versions.

View attachment 484284

I’ve never seen that type

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[Maluisarot]

Never seen them at Screwfix but Toolstation do some. Come in Line/Neutral or Line/Neutral/ CPC. Rated at 32 amps too so perfect for household use too.

 

[Landy Andy]

As you say. It’s due to the wires being trapped beneath the hard fixing that is damaging the wires. If they were just under the squishy part they would be ok.

 

[Maluisarot]

Just got finished up on the repairs and thought I'd give a little update. Went for low temperature solder ring in heat shrink- the white ones are the perfect size.

Anyone else doing this repair in future I strongly recommend using a plumbers heat proof mat to protect the surrounding cables and plastics.

Im also lucky enough to have an Iroda butane powered soldering iron/heat gun. It's small size means it's easy to direct the heat exactly where you need it and also reccomend this kit to anyone who does need to solder in confined spaces/anywhere without power.

All in took about 30 minutes. It's a tight space and there is absolutely ZERO slack in the loom so take your time with it.

Bit late to drill the aluminium plate so that'll be done in the morning.