Fasteners for thin (ish) GRP panels

[Stratos Fear]

I cant remember the name of the fasteners which consist of a loosely held nut in a rectangle of steel with a hole at each end for pop rivetting. I need some for my door cards - can anybody advise me what they are called so I can find them on E-bay ?

As an alternative, I have tried "well nuts" (sounds like slang for an earnest vegan!) which are the compressible rubber things with a brass threaded insert but in my experience they pull out fairly easily.

Any ideas? (and I dont want to use self-tapping screws - sorry!)

Thanks

Peter

[Longtimefan]

See LB Derby, Neil63 stream post 169, curtesy of Chris the Wiz, and Neil.

Robin

[ProtoTipo]

As Robin says, I got some recently from here:
http://race.parts/Catalogue/Nuts-Bolts/Anchor-Nuts/Metric-Anchor-Nuts

'Floating Anchor Nuts'

[Gordon Caro]

The rubber version is called a rawlnut. I first used these when I worked at Lotus in the 80's and 90's. The benefit or these when used with glass fibre panels is that you don't have to torque them up. Craig specifies these for the door panels and they worked OK for me. With a anchor nut or cage nut, these are best suited to metal panels which fit tightly together and can be torqued up.

[Normb666]

Might get shot down for this suggestion....but what about velcro? A few short strips of that along the bottom should hold the card in place just fine. Although, I've not got a car to look at, so don't know (and can't remember from my last Stratos 28 years ago) if it'd be a goer.

[Stableblock]

Caged Nuts too.

[Stratos Fear]

Thanks everyone for your replies - I now know what to call these things for my E-Bay search ! Didnt realise there was such a variety. I've ordered a few well-nuts(Rawl nuts) and a few splay nuts as recommended by Craig.

Norm the velcro might work for perspex windows but almost certainly wouldn't be strong enough for glass side windows - there would be quite a bit of weight bearing down on the slider mechanism - and it would have to withstand lateral forces as well with hard cornering !
Chris - I'll check out Race-parts - thanks for the pointer. (having checked, these are the parts I recall from the earlier post but couldnt remember what they are called or where to get them)

[john]

Velcro can be a really good fix, especially if it can be kept clean and not fill up with stray fibres. Though I think you are right Peter and not suitable for the door cards.
I have made small square plates of aluminium with a rivnut fixed in the centre before now, fixed to the rear of the fibreglass with polyurethane adhesive. Not as professional as bought in items, but if you are accurate in placing them they work well. I used these on door cards and on headlamp pod covers.
I am considering making a removable Grp4 dash top panel fixed with velcro to hide my fuse box and relay panels, but it's only at the idea stage at the moment.

[Guy Mayers]

Back in the day, when I didn't know any better. I put ally (I think) rivnuts straight into the fibreglass to holt the inner door panels in place. With a liberal coating of grease they're still in place 30 years later, never had one seize.
Guy

[Fingers]

Those anchor nuts that Chris posted above are used absolutely everywhere on the likes of Boeings and Airbusses, just about every external panel you see uses them, with 3/16" screws. Usually fairly thin kevlar panels fastened through light aluminium structure, they do the job of holding on really well. I trust them. I bought some metric anchor nuts from Demon Tweeks for my door cards. You can always rivet them to an aluminium strip or plate to spread the load.

[ProtoTipo]

Passenger side Lotus Elise foot rests are held in with velcro.

[Stratos Fear]

Really useful comments - thanks guys (and Guy! )

Chris - I would never have thought velcro would be up to the job for footrests !

[ProtoTipo]

Chris - I would never have thought velcro would be up to the job for footrests !

No, I didn't either, until I tried to remove it.

[Normb666]

If you think about it, how hard is it to "unstick" velcro when you're trying to push "along" the mating surface (i.e. trying to detach the whole thing in one go)? The only reason you can unpeel it fairly easily is because you're separating just a small amount at a time. As Chris found out with the Elise, it's very, very strong, so that's why I thought it'd work for the inner door skins.

Talking of which, don't the inners hang off the top edge of the main door moulding, and that takes most of the weight? Must say I've not looked at the LB setup, but it's how Alloras work.

[Stratos Fear]

Norm - yes the windows hang from the top edge of the inner door panels but the load is shared by the sliders (as I'm sure you can recall) - but there will also be a lateral load - and as Craig reminded me, tension in the glass caused by door slamming whether intentional or accidental. The weight and shape of the glass windows makes them unwieldy and heavy and my concern is that they should be adequately and securely supported under all normal operating conditions - but you may be right about the velcro - it's just that I dont intend to use it !

[john]

Glass windows really are worth having Peter, as I've said to you.
They make a real difference to the feel of the car. Definitely worth some extra effort.
I didn't even know LB had a glass window option. Wonder if they will fit my bodywork?

[Normb666]

John - I believe the new glass side windows will only fit into the new-mould doors, so if you've got an old set, they won't go. But knowing you, I bet you'll be able to make your own up from melting down a few old beer and wine bottles you've still got hanging about since Crimbo.... probably end up nicely tinted too, depending which ones you choose :)

[john]

Might be a step too far Norm��, we do have a source locally which can drill, shape and curve glass but I'm kinda thinkin life's too short. Especially at the moment.

[Willtord]

Sorry I'm late to the party guys, I'm new here, hi.

I've seen manufacturers like Reliant and TVR use "rivnuts" (rivet nuts) in years gone by, to secure fibreglass. In my experience though, unless they're used on thicker reinforced areas, they normally produce cracks in the material, due to expansion of the sleeve during the "rivetting" phase.

Airbus and Boeing use "anchor nuts". These are good because they provide a wider fixing area for the distribution of forces, but unfortunately need rivetting again which can lead to the aforementioned cracks, unless you were to forgo the rivetting, and secure them in place with fibreglass or an adhesive.

"Well nuts" are good anti-vibration mounts, but they result in a less attractive end result if they're visible after they're fitted.

"Jack nuts" and Versa Nuts" are probably a good option, (jack nuts if you're into weight saving!), as there's no expansion of the pilot hole required, but they do need more room behind the panel because they start off being a little longer than the other options.

A few are illustrated here (I'm not an affiliate):https://www.rivetwise.co.uk/rivets/rivet-nuts.asp

Velcro has been mentioned. Mclaren used 3M "Dual Lock" to secure the number plates on the F1 road cars. I've personally used it for numerous applications. It's great stuff, but not a "flush fit" option, unfortunately, it's quite thick. Also not recommended if the part is going to be removed on a regular basis, unless it's used sparingly.

Hope the above helps someone, sometime in the future.:)

[Iowstratos]

Most of the time in the aircraft industry they use wide foot anchor nuts held in place with 120’ counter sunk black alloy rivets which are very soft.

[Fingers]

Most of the time in the aircraft industry they use wide foot anchor nuts held in place with 120’ counter sunk black alloy rivets which are very soft.

I haven't seen those, most of the anchor nuts I've seen on the Boeing and Airbus aircraft I've worked are quite narrow and use ms20426 3/32 AD 100 degree rivets or EC2216 adhesive to bond them on, depending on the structure they're attached to. What are the wide foot a/nuts like? And don't mention those rotten alloy ratching receptacles Airbus use that corrode and split in two after an hour in service! :mad: And when you're putting a panel on you find the very last one pops off!

[Iowstratos]

I have not got the rivets to hand, but hears an anchor nut, floating type.
They were good of the worlds largest hovercraft, heaviest flying boat, fastest accelerating interceptor plane, woulds fastest cars, and the only satellite rockets.
All made on the Isle of Wight!
17028

[Fingers]

I know the ones, they work well. I bought some metric ones the same to use in my Stratos.