Heat shield when using heat shrink solder sleeve

[Ingwe]

I'm going to try and join a broken wire that operates the central locking on the habitation wire. The break is very low down and pretty inaccessible. I thought I'd try some of the heat shrink solder sleeves as they seem ideal for this project. However, in all the demos I've seen of these wonders, they wires are out in the open and the fixer can rotate the joined wires in front of a flame or hot air gun and there are no other wires or plastic door parts in close proximity.
In contrast, I'm going to have to join the broken wire with other wires and plastic parts of the door right next to the join. So I was wondering how best to make a small heat shield that I could put oover the door or between the heated wire and the other things I don't want to melt.
As ever, thanks for the advice which I'm sure will be forthcoming.
Picture attached so you can see what I'm on about. Need to connect the blue wire (barely visible).

 

[Richard n Ann]

When I'm brazing I put a wet towelling wrag behind the pipe, as long as the wrag stays wet it can't go above 100c even though the brazing joint is 600c. Wires and plastics are always OK and are protected ?

 

[jimcg]

Looking at the location of the failed wire it’s likely that as a result of the flexing and bending all of the wires are likely to be close to failure. Did a similar job on my daughters car recently and spliced in new wires which allowed me better access for using the heat shrink connectors you would then have new wires at the flex point so less chance of a repeat failure anytime soon.

 

[Campervan_man]

Pop the grommet out with a flat screwdriver and try gently teasing the wires out a bit ?

 

[Ingwe]

Looking at the location of the failed wire it’s likely that as a result of the flexing and bending all of the wires are likely to be close to failure. Did a similar job on my daughters car recently and spliced in new wires which allowed me better access for using the heat shrink connectors you would then have new wires at the flex point so less chance of a repeat failure anytime soon.

How did you splice in the new wires if they were as inaccesible as mine? I've removed that grommet but there was no futher "play" in the wires.

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[HandyAndy]

RS PRO Nomex Thermal Insulating Sheet, 304mm x 200mm x 0.25mm | RS

uk.rs-online.com

 

[Lenny HB]

Looking at where the break is I would take the door panel off so you can do a proper repair.

 

[Ingwe]

Quite expensive that Nomex insulation sheet, for one job. But useful to know there's such material available. These sheets have given me an idea- I might try and hold a small base plate for standing the iron from an old ironing board. It's thick and it looks like it's heat retardant.

 

[Ingwe]

Looking at where the break is I would take the door panel off so you can do a proper repair.

Taking the door panel off doesn't assist. The wires are covered by a hardened foam type (insulation?). It might be possible to remove this or lay new wires over the rigid foam stuff but I'd need to take the door off its hinges and that is beyond my skills. I really would, ideally, like to replace all the wires and have thought of drilling a new hole in the bottom of the door if I could get new wires down from the lock side of the door.

 

[Mike800966]

Why has this wire broken in the first place? Are the others also likley to fail?
If you can disconnect the other three wires but I would be tempted to cut a square, say about 50-75mm sq out of the door using a vibrating multitool then carry out the proper soldered and sleeved repair and put back an oversize and suitably painted blanking plate with a grommeted hole, you could also usefully sleeve all the wires for a tidier job.
I have a sinking feeling that any soldering in situ will damage the adjacent cabling.
The vibrating multittol need hardly penetrate the cladding material
Mike

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[Ingwe]

Why has this wire broken in the first place? Are the others also likley to fail?
If you can disconnect the other three wires but I would be tempted to cut a square, say about 50-75mm sq out of the door using a vibrating multitool then carry out the proper soldered and sleeved repair and put back an oversize and suitably painted blanking plate with a grommeted hole, you could also usefully sleeve all the wires for a tidier job.
I have a sinking feeling that any soldering in situ will damage the adjacent cabling.
The vibrating multittol need hardly penetrate the cladding material
Mike

The wires have broken undoubtedly due to the continual flexing and I suspect all the wires will break in time. Renewing them all is clearly the best solution. I will go to the van tomorrow and take some more photos and have a further look. The other issue I have is what happens to the wires at the other end i.e. inside the van? I hope that it's obvious where the wires go and that they'll be accessible.
I don't have a vibrating multi tool (quivering maybe ) but could see how cutting a hole in the door would help.
Perhaps when I post the further photos and post back on the destination of the wires, further advice will be offered?
Cheers.

 

[Deneb]

Quite expensive that Nomex insulation sheet, for one job. But useful to know there's such material available. These sheets have given me an idea- I might try and hold a small base plate for standing the iron from an old ironing board. It's thick and it looks like it's heat retardant.

I normally use a solder mat, they're a lot cheaper, about £6 from Wickes or even cheaper on Amazon. Some heat tools for heat shrink cable sleeve and solder connectors also have a shield that sits around the cable and reflects heat back onto the side opposite the gun. It cuts down the amount of heat escaping onto any adjacent surface and directs it all round the cable without having to twist it or move the tool.

 

[Richard n Ann]

I used a heat mat once, I put it behind a pipe I was brazing to protect some cables. The matt was fine, undamaged, but when I removed it the cables were knackered ? ? wasn't funny at the time.
That was the first and last time I ever used a heat mat, some must be ok though ?

 

[Vipar]

From an earlier thread

I am going to try to explain my thoughts on your problem. You need to have patience with me and maybe read my attempt to solve your problem a couple of times.
Cut and inspection panel in the door, obtain a suitable piece of laminate to cover the new inspection hole. In the new piece of laminate fix a socket. ( miniature wall plug type) then connect the wires to this, having perhaps if needed extend them, they will sit inside the door, use self tapping screws to affix the inspection panel back. You could make the inspection panel a feature, use your imagination. If this works please donate £2 to a charity of your choice. If it does not work. I did not write this post.?

 

[Mike800966]

If you cant hide it , make a feature of it! Is Annies solution to most things. Stick a sticker over it!
Multitools are VERY useful. The blade only oscillates about 0.5mm at about 200rpm , I guess, so you get real control over what it cuts.
I picked up a battery operated one in Lidl. With the comb blade attached you can carve through ally or plastic in a trice. Wood a bit slower and even steel sticking out from masonry! , so many uses from clearing off old tiles to cutting copper pipe to length. Blades are now an industry standard, even screwfix sell compatible blades.
Would seriously recommend a diy quality one for this job , even if you cost it to this alone it will be cheaper than paying someone to do it for you. The better ones are made by Fein but crikey they DO work.The only alternative that I can think of is a sharp stanley blade but they are inclined to slip with drastic effect
Mike Oh I forgot and Annie!

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