Replacing a grommet

[Dave Plowman (News)]

One of the harnesses on the old Rover passes through the bulkhead, and uses a special grommet there. The hole is some 60mm and the harness about

20mm diameter. The grommet has disintegrated and new ones NLA - although even if a new one was available it would mean removing some connectors from the loom to fit it anyway. It's also a bit of a pig to fit in the hole, as it will only push in place from under the bonnet and is difficult to get to. The inside is easier.

Any clever ideas on making up a better device which would not only stop the loom getting chafed but seal the hole for noise etc? It would need to be in two halves to fit round the loom, I'd guess.

[The Natural Philosopher]

Ok, this may not exactly be a total answer, but I have had total success in gluing rubber to itself with superglue.

So if you CAN find a replacement grommet, you should be able to split it and reassemble over the wire at least.

Have a look here

see if any of their mass of rubber mouldings looks near enough to be useful

[Donwill]

I have some grommet strip which I find very useful for the odd akward job like yours. Maybe it will do the job for you . Try:

Luck Don

[SS]

I would split a grommet and fit, or silicone sealant

[The Natural Philosopher]

I would probably use BOTH.

But silicone sealant is a good idea. However its hard to mould, since it requires air to set, and if you want to keep it in shape, that means an air excluding mould.

You CAN get silicone rubber casting materials:

it ain't cheap!

[Steve Firth]

"Dave Plowman (News)" wrote: [snip]

I'm not sure about "clever" but I would be tempted to make an in-situ mould on the inside and outside of the panel then carefully fill it from the accessible side using either a two-part sealant or Sikaflex or an MS polymer. I've done something similar on boats when I wanted to pass cables through an internal bulkhead. On that occasion the mould was a pair of corn plasters and the difficult to reach side had bits of electrician's tape over the plaster to stop the polymer from oozing out.

It was tedious to do, but the end result looked like a grommet.

[Dave Liquorice]

Grommet strip? At least for the chaffing.

Sealing is trickier, think I'd look for a suitably sized blind grommet, make a hole some what smaller than the loom in the middle and join that to the edge with a single cut.

[MuddyMike]

If it needn't be pretty a piece of rubber hose of the right size about an inch long and split down its length with a spiral cut does the job.

Mike

[Dave Plowman (News)]

- I've seen that stuff. Sadly the grommet fits a 60mm diameter hole in the bulkhead while the hole in the centre of it to seal over the loom starts out at about 15mm. The outer part of the grommet is still ok - it's the thinnish rubber membrane and the inner hole part which has split and perished.

[tony sayer]

In article , Dave Plowman (News) scribeth thus

Liberal applications of Silicone sealant?..

Or there is a sort of grommet on a roll/ strip thing have some of it here think RS stocked it...

[Mike Tomlinson]

In article , Dave Plowman (News) writes

Slit some T&E cable along the side (not in the centre) and pull the insulation off. Cut to length. Push over the edges of the hole - some glue might help here - and trim for snug fit. May well work better on a warm day when the PVC is softer.

If you have some spare 2-way cable (3 cores+earth) this is wider and so may be a better fit, or may not depending on the hole shape.

[Dave Plowman (News)]

Think you need to check the sizes. The hole is approx 2.5 inches diameter. The loom approx 3/4 inch.

[Donwill]

> Yes - I've seen that stuff. Sadly the grommet fits a 60mm diameter hole in

I guess it's some kind of moulding technique then as others have suggested, maybe black silicone rubber or something similar. I don't know if there is a 2 part epoxy moulding compound like metal putty (or whatever they call it) but remains flexible after curing? Good luck Don

[nicknoxx]

>

How about Sugru.

Mouldable, flexible when cured, less messy and more controllable that silicone sealant.

[Owain]

60mm panel hole, 2.4mm panel thickness, 90mm overall dia., semi-blind grommet part number RSB600-24-00F

[Ericp]

The NP has given the exact course of action. Cut it, fit it and superglue closed.

[Harry Bloomfield]

Dave Plowman (News) explained on 25/03/2011 :

I would suggest asking in an electrical wholesaler, except 60mm is unlikely.

You can buy a U shaped material called grommet strip. You just cut a length off, the same as the diameter and push it into place with maybe some glue in the U to keep it firm. Then temporarily fix the cables in the middle of the hole and squirt some silicon sealer around the cables to seal the hole completely.

[Dave]

is, or a similar product, used extensively in the aerospace industry for holes where a grommet would not do.

An alternative way would be to find a cored cable and slice it end to end and throw away the cores and slot that into the bulkhead, cutting it to length when you get it fitted.

HTH

Dave

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember The Natural Philosopher saying something like:

That's cheap.

[Dave Plowman (News)]

I'll have another go at explaining the problem.

The loom is very much smaller than the hole in the panel.

I want a good seal between the sides of the panel - to stop noise, draughts, water, etc.

There are large connectors either end of the loom which prevents just sliding on a new one, if it were available.