Heat Shrink

[Ian Cooke]

Not related to the current fabulous weather but rather the need to replace a PO's efforts of wrapping various wires in copious amounts of insulating tape!

I have in mind removing the tape and replacing with heat shrink tubing and wondered if anyone has any experience and recommendations that they can share.

Thanks

Ian

[JJC]

Hello Ian: Lot of work, looks nice, accomplishes nothing ( it does let you examine old wires, however ). That being said, I do stuff like that all the time, so go for it !! LOL It's almost as useless as waxing the bottom of the tire well, but you always feel a sense of pride when done !!

JC

[politeperson]

Not quite sure what JC means.

What you need is something like this.

https://www.ebay.co.uk/itm/Black-Heat-s ... Sw8-FaawZi

We used to shrink it with a lighter in the old days, now a heat gun.

I assume you know how to solder?

Dont see how you can do any automotive electrics without it.

Jmaes

[3edc4rfv]

I encapsulated my new engine bay wiring harness with clear heatshrink and sealed all wires and joints with a glue/sealer compatible with the stuff (sorry I don't have a name for it). This should keep the lower quality wiring and insulation safe from oil leaks and rain containing modern pollutants. \
Oh ya, all connectors where liberally coated with Dow corning DC-4 lubricant and dielectric. This will prevent corrosion of the connectors for a loooong time.

[tim wood]

When I extended my wiring to cope with the RHD conversion I used heat shrink over the joints ( either bullet or spade ) and the wrapped the new wires in harnes tape which is non sticky. Just to make sure it didn’t come undone I placed a couple of turn of normal insulating tape at each end of the new harness.

Seems to work so far.

( ok I know some, maybe most, would say change the harness)

By the way to shrink the tubing I used the thing from the kitchen kept to light the hob should the piezoelectric system failed.

Tim

[Ian Cooke]

Thanks Guys that's very helpful.

Presumably I can get longer lengths of the heat shrink or is it a case of using multiple shorter lengths to cover longer lengths of exposed wire?

[christopher storey]

It all rather depends on how thick the loom that you wish to re-wrap is, and more particularly how big the connectors are at the ends of it, because the heat shrink must be of a size that will pass over the connectors. You are almost certainly better off buying the proper loom tape ( not insulating tape ) from e.g. Autosparks and wrapping it in the way the loom assemblers do with a new loom . This will make a finished job far better looking than heatshrink, which once shrunk shows every knobble and blemish in the underlying loom

[politeperson]

You should use both really. Heatshrink, then wrapping.

You can purchase heatshrink in 1 m+ lengths. This is much cheaper than buying a box of pre-cut lengths.

Inserting wires into long lengths of heatshrink could be challenging though, I have a friend who manufactures VW looms. They have to hang the sleeve off a 5m high gantry and pull them through.

They then use looming tape to give the correct look. The best stuff has a period a cotton exterior appearance, just like the original loom.

The bundle of wires is then taped together every 20 cm or so in preparation for wrapping.

The secret to wrapping is to wrap the tape directly from the tape roll. By pushing the tape roll around the bundled wires, you maintain tension in the tape as you are wrapping, giving a much neater job. If you cut off a length of tape then try and wrap it around the wire you are asking for trouble.

A thin blade is essential, as ripping the tape stretches it and it can start to peel off.

Also, if you are soldering avoid dry joints. This is when hot solder heats a cold wire. The solder sits on top of the wire creating resistance. You must use the heat of the wire to melt the solder on each wire individually. Then heat the two "silvered" wires together to re-fuse them. This also reduces the need for having three hands.

[BRM]

For metre lengths of heatshrink in various sizes - and virtually everything else electrical you will ever need - try

http://www.vehicle-wiring-products.eu

When I rewired my Healey I modified the loom for various different reasons and bought countless stuff from them. Always good service.

[politeperson]

Yes Brian, they have an excellent website I must say. The prices look good too.

[Ian Cooke]

Thanks all. I have ordered some looming tape which I'm sure will be a great improvement on the insulating tape that's everywhere at the moment!

Many thanks for the link Brian. Looks like an excellent source for all things auto electrical!

Ian

[mark10337]

I'm not sure if you are getting heat shrink and standard sleeving mixed up.

Heat shrink is used to insulate and add strength to connections, e.g. joining 2 wires or a wire onto a connector e.g. a ring or spade connector.

Sleeving is sometimes used to loosely group some wires together. e.g. 2 wires to the cig. lighter.

Loom tape is used for binding together several wires traversing the same path. e.g. Front to back of the vehicle, side to side etc. From these paths, branches often come off which may also be bound or sleeved.

Oh, and you can use a hairdryer or paint stripper heat gun to shrink the tubing. This gives a better, more consistent result than a naked flame

[Series1 Stu]

Heat shrink is used to insulate and add strength to connections, e.g. joining 2 wires or a wire onto a connector e.g. a ring or spade connector.

Yes, and because of that ability it would make your loom rather stiff and inflexible if used along it's entire length. Loom tape is better for this purpose. If you want to make a really good job of it, use self amalgamating tape. This forms an homogeneous mass as it gets overlapped on itself. Very nice, although not as easy to make changes once the loom has been wrapped.

Regards

[3edc4rfv]

If you want to make a really good job of it, use self amalgamating tape. This forms an homogeneous mass as it gets overlapped on itself. Very nice, although not as easy to make changes once the loom has been wrapped.
Regards

There is now a clear version of this stuff. I found some on Amazon, made by 'Nashua', part # D-7124-1 and billed as "silicone self-fusing tape".

[Ian Cooke]

You're right Mark, I am getting the two mixed up.

So, I want to replace the copious amounts of insulating tape that a P.O. has used on various wires following the same path e.g. running between the two brake fluid indicator switches.

It would seem from what you are suggesting that loom tape is the best option or possibly sleeving?

Ian

[mark10337]

Hi Ian

:-) I am about to replace that exact section on mine! (LHD though)

It also depends what the PO had used the insulating tape for - to insulate a join made (replace with heat shrink) or to just bind them together out of the way.

I will have the wires between the two reservoirs without any further wrapping, binding or sleeving. Then from the rear reservoir it will be loom taped wrapped as a branch of the main loom. That keeps things a bit tighter in the engine bay as opposed to sleaving.

The spade connectors on the end of the wires should of course be soldered and heat shrink applied over the join. Some advocate the use of clear heat shrink so you still give support to the join but can see if there is a break later on. Don't forget to put the silicon spade connector covers on before you solder the spade on ;-)