Rivnut vs Pop Rivet ... and what metal

Wondering from experienced overlanders what they prefer, and why, for pop rivets or rivnuts?
Internal and external.
Secondary question... May sound silly, but I am new to this - what material? Stainless or aluminium? I'm not sure what different parts of the defender are made from.

Thank you

Rivnuts or pop rivet, rivenut for larger jobs, pop rivet for smaller ones. Defender body's are mostly aluminium.

Is the bonnet and wings aluminium? I thought the bonnet was steel at least?

All older models have aluminium bonnet skins on a steel frame. I know that later models like yours will have steel door skins but not sure about bonnet. Wings are ali.

Test your panels with a fridge magnet. As far as I know all rivnuts are ally (correct me if not so). Try and avoid having stainless in contact with ally, the ally will corrode especially in winter when the roads are salted and in coastal areas.

Wimblowdriver said:

Test your panels with a fridge magnet. As far as I know all rivnuts are ally (correct me if not so). Try and avoid having stainless in contact with ally, the ally will corrode especially in winter when the roads are salted and in coastal areas.

Click to expand...

All good, except you can get steel rivnuts.

Most of the Defender bodywork is an aluminium alloy called Birmabright. Bulkhead, foot wells and door frames are steel. The Puma bonnet is steel too I I believe.

300bhp/ton said:

Most of the Defender bodywork is an aluminium alloy called Birmabright. Bulkhead, foot wells and door frames are steel. The Puma bonnet is steel too I I believe.

Click to expand...

defenders never used birmabright ,it was finished by 1980 iirc which is why later series and defender panels oxidise more

Pop rivets are great, but in any high stress area they will loosen, at least with rivnuts you can retighten the bolt or reset the rivnut, but they have their own drawbacks if not clamped/set properly and the bolt not greased when assembled.
The alloy rivnuts seem to have a larger head than the steel versions.
A proper setting tool is a must, Avdel make a good hand held one, plus of course you can reset the rivnut in service.

A good tip when pop rivetting is to put a thin smear of silicone selaant between the two bits of metal, this will allow some movement but not enough to make the rivet come loose.
Cheap rivets are just dog ****e.
Also the drill bit needs to be the exact size of the rivet, even slightly to large is a recipe for futyre failure.

Monobolts are really good, but the tools to set them are several hundred quid.

Rivnuts! Hate 'em. Useful and sometimes the only way to get a firm fix in a blind hole, but can you guarantee that it's set tightly enough? Having to cut/drill them out when the screw "spins" them is a sod....

Older Land Rovers and Defenders are made from lovely steel and Birmabright.
Newer JLR models are apparently made of Cheese and recycled egg-cartons
Completely bio-degradable if left out in the wet for any extended period.

ogb said:

Rivnuts! Hate 'em. Useful and sometimes the only way to get a firm fix in a blind hole, but can you guarantee that it's set tightly enough? Having to cut/drill them out when the screw "spins" them is a sod....

Click to expand...

Shouldn't be a problem if the hole is accurately drilled and dry, and you use a quality rivet and setting tool.

As for removal, as with most things on a landrover, small cold chisel and a lump hammer works wonders, and is quick.

DanClarke said:

Older Land Rovers and Defenders are made from lovely steel and Birmabright.
Newer JLR models are apparently made of Cheese and recycled egg-cartons
Completely bio-degradable if left out in the wet for any extended period.

Click to expand...

defenders arent made of birmabright neither are later series

jamesmartin said:

defenders arent made of birmabright neither are later series

Click to expand...

Sorry, I thought Most of them were Birmabright. Silly Me.

I believe it was changed to 5251 as Birmabright was a trade name of Birmetals that went bust in 1979..........
Still, as others have said, use ally rivnuts on aluminium and steel on steel.

Rivnuts are easily available in alluminium, mild staal, stainless steel and if you are very rich, you can get them made of Marine Bronze, although I can't remember the specific grade, but they were horrendously expensive as they are also used in explosive atmospheres.
If inserted correctly, they will last for many years and should never need drilling out to allow chamges of component parts, unlike easily fitted pop rivets or even standard rivets (which not many people know how to fit nowadays)