Classic cars forum & vehicle restoration.

rcx822 · Joined: 31 Dec 2010 Posts: 112

I've rewired my car. This photo shows a hole in the bulkhead (that's the metal between the engine bay and cabin right?), and you can see two wiring looms going thru it plus two 13mm OD hoses for the pneumatic locking diffs.

A regular seal won't work here because of the irregular shape that the breathers and wiring makes plus that the wiring and breathers go in two different directions, making an obtuse angle.

Ideas on how to seal this? Car is an off roader so especially important to seal up!

Peter_L · Posted: Fri Dec 05, 2014 4:21 pm Post subject:

Perhaps additional holes of suitable size to allow one grommet per tube and one per cable would be better than trying to "bodge" a solution.

I found that running cable through flexible plastic pipe rather than the spiwrap, which is introducing gaps into the equation.

For trouble free pass through, rubber bushed thread and nut adaptors and silicon caulking.

ukdave2002 · Joined: 23 Nov 2007 Posts: 4105 Location: South Cheshire

I would tape all the cables tightly together as best you can ( there should be enough slack in a wiring loom to accommodate an entry / exit angle change) purchase a blanking grommet, cut or punch a suutible undersized hole, fit ....jobs a good un Smile

use a dab of sealant if you need too.

Dave

Old Wrench · Joined: 23 Dec 2013 Posts: 226 Location: Essex and France

Looking at those blue pipes, they are rubbing against the metal: not good.

I would adopt the competition car solution (Bulkheads must be fire-resistant); make up an ally plate, and use separate grommets for each feed. Seal the plate to the bulkhead using body sealant mastic, and fasten with either Monometal Pop Rivets or Self Tappers.
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Well, apart from that, did you enjoy the play, Mrs Lincoln?

Peter_L · Posted: Fri Dec 05, 2014 7:01 pm Post subject:

ka · Joined: 03 Dec 2007 Posts: 600 Location: Orkney.

If you are attempting a fireproof bulkhead, than I think the alloy plate, sealed with F/R sealer will do just the job. If you just want to fill the hole, position the loom, pipes etc in the hole centre, then use builders expanding foam. Available in an aerosol, and expands as it comes out of the aerosol, and sets hard (well as hard as foam sets!).
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KA

Better three than four.

Bitumen Boy · Posted: Sat Dec 06, 2014 9:40 am Post subject:

rcx822 · Joined: 31 Dec 2010 Posts: 112

Thanks for all the suggestions. I have seen some forum posts of people using sealants and expanding foam, but no photos and I can't visualise it. The hole is big, and the sealant would need to stop the wires moving in and out the hole.

Another thought I had was to use the OEM style grommets with the long "tail" like in the photo and then fill the tail with sealant to seal around the irrgeular shape formed by the hoses and wires. But finding the right size grommet will be difficult or impossible.

So maybe the suggested "competition car" solution, of the alloy plate and suitable grommets is the way to go. It unfortunately will require cutting the bulkhead but solves the problem properly.

D4B · Joined: 28 Dec 2010 Posts: 2083 Location: Hampshire UK

There are all sorts available:

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2055119.m570.l1313.TR1.TRC0.A0.H0.Xbulkhead+grommet&_nkw=bulkhead+grommet&_sacat=0

Or how about a rubber gear stick gaiter perhaps:

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR1.TRC0.A0.H0.Xrubber+gear+gaiter&_nkw=rubber+gear+gaiter&_sacat=0