Probably a daft question but can you put rivnuts in the top of a fuel tank? Will they hold and be fuel tight?

Is it best to epoxy them in?

I've put them in mine - then put the gasket over the top and bolted the fuel sender down.

I'm assuming this is good enough - that's what it says in the manual

If not - I might have some 'fireball assisted acceleration' at some point

Should be fine as long as its all sealed.

No to rivnuts and no to epoxy and rivnuts.

Weld a threaded boss externally and pressure test the tank afterwards.

Nick,

How exactly do you do that when you have a tank where the only hole is the one you have just cut is for the sender?

And not everybody has the tools to weld alloy.

I know of at least 10 people who have used RivNuts and not had a problem? Can you supply evidence to the contrary - would be interested to know and might even consider hacking the tank apart...

Cheers,

Murray

if you really want the hear all the possible "no"s i'll ask my mate who designs fuel systems for a living. the only problem is he's convinced we're all going to die a horrible firey death anyway as we break so many regulations / rules that he has to stick to.

(Hence not asking him)

LOL Mike.

Ok - don't wanna hear it

What's that saying...

"Ignorance is bliss...."

Well it could be converted to...

"Ignorance is blistering your body with 3rd degree burns"

I think I'm going to stick to my rivnuts, plus gasket and bolts - I can't see it being an issue - I really cant...

Sorry to 'lengthen the debate'

Still like to hear nicks view tho, especially as a few people seem to have done it now.

Jim, you need to upload them into your photo archive before you link to them (i think)

Ah ah thanks Mike

So like this:-

Just use the sender gasket and some petrol proof flange sealant.

Cant get the pics to appear so hear are the links to pics in my profile.



http://www.locostbuilders.co.uk/photos.php?action=showphoto&photo=106-0628_IMG.JPG





http://www.locostbuilders.co.uk/photos.php?action=showphoto&photo=106-0630_IMG.JPG
- Jim

[Edited on 19/3/06 by jimgiblett]

[Edited on 19/3/06 by jimgiblett]

quote:

---

Originally posted by muzchap
LOL Mike.

Ok - don't wanna hear it

What's that saying...

"Ignorance is bliss...."

Well it could be converted to...

"Ignorance is blistering your body with 3rd degree burns"

I think I'm going to stick to my rivnuts, plus gasket and bolts - I can't see it being an issue - I really cant...

Sorry to 'lengthen the debate'

---

My sender uses rivnuts to hold it in too, as long as you use a proper fuel resistant sealant (eg certain instant gasket products) to seal the threads then I can't see an issue. I wouldnt put them on the base of the tank to hold in a fuel pump though, for obvious reasons

[Edited on 19/3/06 by ChrisGamlin]

Hi,just to fan the flames a bit more, I think the real problem of using rivnuts would be more relevent with a turn over of the vehicle .
If you are sure the tank would not leak from there or anywhere else you should be ok.
Truth is you would probaly get more leaking from the breather or filler.
Having said that I had a 20mm boss welded to the top of my tank for the internal pump and self tappers and a rubber gasket for the sender.
I also,a few years ago was stuck in my harnesses upside down with petrol pouring out and finding myself unable to release myself,its not very nice!
It was fill your pants time!!!
Dean.........

Sealed "Rivnuts" are available. These are effectivly a blind tapped hole. If you installed these with petrol resistant expoxy (not many are!) then this should do your job.

Avdel Textron sell them.

John

Perhaps I should have offered an alternative method other than welding when I gave my honest and well meaning opinion on rivnuts and epoxy in a fuel tank.

First, an alternative method.

Use sealed nutplates, these are aircraft spec. captive nuts on a little 'bi-winged' plate that are secured with a sealed end countersunk rivets at each end of this 'bi-wing'. Fluid will not pass out of the nutplate or the rivet. Your coverplate can then be fixed with an appropriate gasket.

They have significant advantages over rivnts, they do not start to spin at the most inopportune moments and they do not need any special tooling other than a drill and a pop rivetter and they are self locking. They are however more expensive, but you get what you pay for.

Epoxy gets eaten by petrol, having had to do emergency repairs on a fuel tank in a racing situation and found that you get about 10 mins before the petrol gets behind it and pushes it off. Epoxy use on any aluminium needs careful prep. as ally is self-releasing so a bit of petrol just makes things worse.



[Edited on 20/3/06 by Nick Skidmore]

Hi Nick,

I don't think your comments were taken the wrong way

Thanks for the advice - all VERY usefull information, which I'm sure 99.9% of people will agree

I'm off to panic now - after fitting rivnuts to my lovely tank at the weekend