Rivets which leave a neat finish both sides

[EFA]

Is there such a thing? I need to rivet two panels together which will be visible from both sides. One is ally, one is painted GRP.

 

Pop rivet is OK on the good side - What I need is a double sided pop rivet, but so far as I know there is no such item.

 

Any suggestions?

 

Edited by - efa on 8 May 2010 16:33:04

[EFA]

Reading this here it seems an avex rivet is wha is required???

[lavena]

Isn't your answer in the first of the article, here - "solid rivets".

 

 

RoadSport 175 SV

 

Edited by - lavena on 9 May 2010 12:00:55

[EFA]

I need to undersatnd the tool. What does a "bucking bar" look like, and what part of the process needs a compressor?

[Willie.]

here

[rj]

Arnie

 

 

This is pretty much the technique used for riveting the boiler of steam machines and which was used for the Eiffel Tower.

 

Also like suggested by Opposite Lock used for assembly of aircraft parts.

 

One of my former friends was a flight mechanic. He was taught how to build a front section of a wing, so I guess you can visit any skilled aircraft workshop to have the process demonstrated.

[elie boone]

Why not glue both panels together ?

[CageyH]

I would be concerned about using a solid rivet to bond a GRP panel.

You may crack the panel if using aircraft standard panles.

 

There is a reason we don't rivet Carbon together

 

Only dead fish go with the flow....!

[EFA]

I am trying to similate a car made entirely of aluminium panels..... Hence I need to have it look as though its traditionally built. (there are around 4000 rivets on the external body whihc do nothing except add an authentic look!)

 

So glueing could be used for the bond, but I still need something whihc looks like rivets - at elast on the inside of the car (which is panelled in bare ally).

 

Perhaps gluing it structually, then machininbg down some rivets and gluing the heads on could be the best solution. Faker than Jordan's breasts, but it would do the job....

[Willie.]

Arnie,

 

Was thinking about this, and although I initally thought solid rivets would be the ideal job, if its GRP and ali, its likely going to be out in the middle of a panel some place that is awkward to get at both sides to thump the rivet over, and it could be tricky to do without damaging the GRP. Definitely worth looking into, in my opinion.

 

Bearing in mind you have 4000 to do, I'm guessing cost is going to be a bit of a factor...aswell as speed. An alternative might be to use something to give the dome on the outside (Maybe a hollow "solid" rivet, like this here) and then pop rivet into it from the inside. If you could get something like a domed nut, without the nut bit, it would be ideal.

 

I've never used the hollow rivets, so not sure how they look or rivet up when used as a normal solid rivet (i.e. thump the end with a hammer).

 

The other thing you should consider, but again I've never used them, is a kind of screw/nut arrangement which some rivet manufacturers do, see here for example. The difficulty you're going to have is depth, as unless your GRP is very thick, I doubt you could get any more than a few threads width within the thickness of your two panels.

 

If you could do something like run a 1/4" thick bit of flat aluminium bar, say 1/2" wide, along the line of the "rivets", you could stagger them and actually tap the bar and screw in from either side. Major work, but an option if you're stuck.

 

If you have a local model engineers soceity or anything, speak to them about solid rivetting. They'd be able to show you all the options and maybe even lend you what you need.

 

All the best,

 

Willie

[EFA]

Sorry, I should have been clearer - the 4000 rivets I can get away with normal blind rivets as the backs are not in a cosptically sensitive position.

 

The area I have the problem with is the rear bulkhead, where one side is very visible from the cockpit, and the other side is the painted rear of the engine bay. They are around and beside the small window which separates the two areas of the car.

 

Foxy Smith and I concluded solids are a nogo for the same reason of damage to the GRP, so we are now looking at bonding and epoxying the rivet heads in to make things cosmetically correct at least.

 

Do you know if onece rivetted, you can press the mandrel out of a normal ally rivet? Ding this, grinding surplus material off, then a skim of P38 may aslo be a solution on the GRP side.

[CageyH]

Glue some half lentils on. If it's good enough for a Spitfire, it should be good enough for a Ferrari replica

 

Only dead fish go with the flow....!

[Willie.]

Arnie,

 

You should be able to knock the steel "mandrel" / pull pin out of the rivet, just need to be careful that you don't damage the GRP by excessive blattering. If you can get someone to hold a block of wood or something against you, it'll give you a much better chance of getting them out without wrecking the show.

 

As far as the grinding is concerned, you'll need to be very careful. Its the mushroom that stops it pulling through, so the more you grind off...the weaker it will be.

 

I'm wondering if you could get a thick countersunk washer, and a put it on the "dirty" side of the pop rivet, so it mushrooms into the countersunk area...then you can bash it mostly flush and skim over. Gets you the same result, only a bit more grab, if you know what I mean.

 

Interesting problem.

 

Willie

[EFA]

CH, thanks for the suggestion. How do they perform under heat and moisture?

 

OL - a better solution. What I was thinking is to use them as a fix while bonding, and once the PUadhesive has cured push out the mandrels and cut the back flush. Its more a case of them not falling out over them providing any structural integrity/strength.

[Willie.]

Hi again,

 

I'm getting quite interested in this. I do think if you grind the backs totally off, they will work loose and fall out. To stand any chance, could you use a thicker rearside panel (if its the ali one), countersink it and let the rivet mushroom into it, so you dont grind it all off? I would suggest not doing that to the grp, as it will splinter being so thin.

 

If the grp is the rearward side, and you dont have all that many to do, how about holding a domed solid rivet in the vice by the tail, drilling in so you almost come out the dome, then cutting the tail off to leave you a domed head with a drilling from the flat side. You could then either pop rivet through your panels and into it, or drill it bigger, push it over the mushroomed rivet and just bond.

 

What do the other '4' builders do? This is the difficulty you get into when you start dealing with awkward Italians... 😬

 

Willie

[Crudders]

How authentic do you want to be? I'm thinking socket button head screws. M3/4/5 will give you a head dia. of around 4.5/7.5/9.5 respectively. Provided that you have a few mm o/a thickness (I'm guessing at least 6?) you could use an unexpanded slimline rivnut within the depth of the ali/grp, into which your cut down screws could be, well, screwed, leaving an identical button head on both sides. You wouldn't have a massive amount of thread engaged but with threadlock it should be pretty permanent.

 

My titanium stone guards are fixed with socket button head screws and they do a passable impression of rivet heads (screw, rivet, rivet, screw, just like that, ha-har) unless you press your nose up against them. Mine are stainless but you could use silver anodised ali, available from all good motorsickle bling merchants.

 

Just a thought.

 

Cruds

[EFA]

Crudders, My good friend Mr Chiswick has come up with the solution - using aluminium "snap head" rivets. These were according to my learned friend used on sports cars right up until the availability of pop rivets in the 60's. So not too out of place, and certainly will give the required finish.

 

Thanks for everyones help on this, I now seem to be making progress on an area of the car which was becoming a real headache.

[Crudders]

Excellent Even more optimistic now of a Clegg/Cameron hatchet burying alliance, though I'm sure neither of you would admit to being anywhere left of Ravey Davey

 

I'm sure I have an inherited baccy tin of those ali snap rivets somewhere - at least I now what they are, if not where they are

 

Cruds

[Willie.]

Are snap heads not just solid rivets?

 

Got a photo? Keen to see what these are like...could come in handy for future projects.

 

Willie

[EFA]

OL here and yes they are very similar.

[Willie.]

Arnie,

 

You'll have to excuse my ignorance, but whats the difference in these and solids? Do they have a difference "firing" method or something? They look like they just take the normal thump or crimpy yoke to put a them in.

 

Willie

[PAC]

The alloy snap heads are what aircraft -and old alloy cars- are held together with. The problem you'll have is supporting the head whilst you whack the otherside.

 

There is a semi-circular mandrel made for the job, but it would normally be held in a vice and the work brought to it.

 

You'd need a large lump of steel to cope with the inersia of the hammer blows if you were to attempt riveting insitu.