Fixing things in place under the bonnet

[peter_mcc Senior Member Find all posts View Profile Close peter_mcc]

How do people fit things like relays, circuit breakers, etc under the bonnet?

I like Craig's idea of using a plastic sheet to hold them - shown in this post. But I can't see how to mount the plastic sheets.

There are some holes with welded nuts scattered around but nothing in the right spots (facelift diesel GXL).

Is it considered "ok" to use self drilling metal screws? I'd use nuts & bolts but I can't see how to get to the "back" of the sides (ie between the engine bay and the outside world).

What have other people done?

[Fred63 Advanced Member Find all posts View Profile Close Fred63]

i prefer to make brackets to fit existing spare holes or welded nuts.
Self drilling screws would be my absolute last resort.

Behind the Air filter is a good location to mount brackets for what looking to mount perhaps as there are some spare 8mm studs

[MacroP Member Find all posts View Profile Close MacroP]

I have a nutsert kit for this. Another term is 'rivnut' or 'clinchnut'. It is like a pop-rivet with a thread on the inside instead and you use a tool not dissimilar to the pop rivet gun. I have a nice kit with M3 all the way to M10 nutsert. You'll need strong hands for the larger nuts to crimp/crush. For relays and such the M5 sized nutserts are the perfect choice. And it allows you to use a nice bolt or set screw. In my case I try to use stainless rivnuts and stainless fasteners. Perfect for firewalls and inside of guards and a thousand time better than using a self drill screw in this sheet metal. Been using these for years.

[Spilsy Avid PP Poster! Find all posts View Profile Close Spilsy]

I've used existing holes, existing studs and tech screws (for a relay and a bracket to hold cable). All seem to work well. I've made a custom plate to bolt my dual battery gear to, which uses existing holes in the wheel arches.
Rivnuts seem to be a great idea.

[peter_mcc Senior Member Find all posts View Profile Close peter_mcc]

I've ordered a Rivnut kit from Just Tools - hopefully it will arrive in time for the weekend so I can finish the install off before going away soon after!

It doesn't have stainless steel inserts - none of them do (at least without spending big $$$).

Looking at the holes in the car already some are 9mm - right in between M5 & M6 hole sizes. Do they need to be a tight fit in the hole or can they rattle around a little then pull up tight? I might have to drill them out 10mm.

[maulbeagle Senior Member Find all posts View Profile Close maulbeagle]

They need to be pretty tight. Some of the places I've read about these say to drill the hole undersize then knock the insert in with a hammer.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Just drill the size recommended and pull the rivnuts nice and tight. I have installed hundreds and had maybe a handful that needed to be re tightened. Usually because it was at the end of the day and I was knackered. If you knock a rivnut in a thin panel you will buckle the panel. Like the others I use existing studs and holes first then rivnuts. Make sure you deburr the hole and use a zinc rich primer. I also run some zinc rich paint around the rivnut before installing.

[Rusty62 Advanced Member Find all posts View Profile Close Rusty62]

We ran out of room for the circuit breakers so fabricated a small bracket and mounted to the battery hold strap. Leave enough wire to allow for battery removal.
Uses the wing nuts to secure in place.




Rusty.