# to Pop Rivet or Seam Weld ?



## nick the tubman (Jun 28, 2006)

there is a stunning R32 on piston heads that has been fully pop riveted instead of seam welded.

i quite fancy this route as it will be a lot quicker/less hassle than scraping back all the rubber/paint etc...

anyone got an opinion on this method.?


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## R32 Combat (Jan 29, 2004)

Got a link?


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## John Sowden (Dec 17, 2010)

Wouldn't touch them with a barge pole! Don't know about cars, but on aircraft they cause dissimilar metal corrosion and are a pig to remove as they spin and make the hole bigger! They are only used for quick fix line repairs. You'd need to use Cherrymax or Cherrylock aircraft standard fasteners with a proper sealant ie PRC or Mastinox and a good dose of water displacing corrosion preventative such as Dinitrol or Corban. Humble opinion only!:smokin:


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## tyndago (Oct 24, 2002)

The Japanese seem to like it. I think its a bit odd. 

Looking at most race cars out there, seam welded.


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## nick the tubman (Jun 28, 2006)

R32 Combat said:


> Got a link?


no sorry, mate was a thread from another site...


to John Sowden:-
some interesting stuff you say there mate...
but a couple of questions:-
i was told welding can distort the metal as well? 
if you undersealed the car with waxoil afterwards, it shouldnt be a prob? 
and why would you want/have to remove them? this car is purely for track use


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## mattysupra (Oct 31, 2008)

i think it looks shit to be honest. 

To me it looks like someone got over excited with there new tool and cant afford a welder. 

Along with the issue of corosion.


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## John Sowden (Dec 17, 2010)

re removal...hit a kerb, get side swiped etc, need to put another part on end up with b great holes in main structure, not good!


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## Adam Kindness (Jun 22, 2002)

seam weld!


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## lightspeed (Jul 11, 2002)

Autoselect are the main culprits. They use sealer and stainless rivets. Not my favourite though mainly due to the closeness of them. If the rest of the car is awesome then I wouldn't let it put me off too much. Just don't drive it on salty roads.


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## mambastu (Feb 13, 2002)

Sucky idea. Drill loads of holes in the metal and then insert rivets which invariably work loose. Must weaken rather than strengthen. 

The Z tune had riveted carbon fibre panels on the front struts as additional re-inforcement. Does anyone know if they also bonded the panels with adhesive too ?


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## narface (Apr 9, 2010)

One of the reasons why some tuners might opt for rivets over welding is because introducing heat to panels that are 20 years old (think BNR32) will increase the chances of rust.


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## mattysupra (Oct 31, 2008)

narface said:


> One of the reasons why some tuners might opt for rivets over welding is because introducing heat to panels that are 20 years old (think BNR32) will increase the chances of rust.


I dont get that? how does it increase the chance of rust? Surely you paint over the welds after? 


I would say pop rivets cause rust as you have bare metal holes that get filled by a bit of alloy that is not water tight. Unless people drill the holes and then paint the drill holes before putting a pop rivet in there?


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## narface (Apr 9, 2010)

mattysupra said:


> I dont get that? how does it increase the chance of rust? Surely you paint over the welds after?


I'm referring specifically to old cars like the R32, with body panels that are 20 years old getting exposed to heat. Apparently, this might increase the chances of rust developing. It may be because of metal fatigue, it may be because of the natural oxidization of the metal over the years, it may even be the compounds of the metal used. I'm not entirely sure of the science behind it.

My GT-R mechanic told me from experience; and I also read from issue 095 (Nov 2010) of Japan's GT-R Magazine... I'll quote and give a brief translation on the article about restoring GT-Rs:

(Taken from GT-R Magazine, Nov 2010, issue 095, page 16)
Article title: Countering Rust (an interview with Yokosuka Metal Works)
paragraph six:
"Unless it is absolutely necessary, Yokosuka Metal Works will not use any _additional_ spot welding when restoring GT-Rs. From new cars to old car body panels, rust formation is unavoidable. The heat from spot welding will accelerate the development of rust on these panels."

Again, this is a very brief translation of the article.

I should also point out, this article was written with restoring and preservation in mind. There are, of course, fixes on car bodies that can only be repaired with welding. But for that extra body rigidity, in the mind of a restorer preserving a car for as long as possible, extra welding is not recommended. Race cars were mentioned in previous posts. For race cars, engineers come from the point where they need to extract the full potential of the car for that race. That's why they are not concerned with preserving the car. They will probably only be using that race car for one season anyways.

So there you go. There's no absolute way of preventing rust. We're constantly fighting to find a way to slow down the process. I guess it's a matter of trial and error, and the experience of the restorer. There are different ways to prevent rust, and there are bound to be arguments over which is better. Welding or rivets? It's a personal choice, I guess.


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## GT-R Glenn (Nov 9, 2002)

yeah got that,
So why would you even consider pop rivivting or seam welding a car that WASNT a race car ?
Acid dipping the shell, or media blasting is pretty much the norm on a serious race car.
Hows that any different as far as rust goes ...


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## mattysupra (Oct 31, 2008)

I think they are reffering to welding a panel that you cant get to the rear to paint protect the weld you have created. 

Basically where to bits of metal get seemed together where moister can get between the two. (33 strut tops for instance) 

If you weld metal and then clean and protect a weld then rust cant form. Rust will on form on metal that doesnt have a protective layer surely?


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## R32 Combat (Jan 29, 2004)

The aeronautical industry refer welding as a continuous defect. I know that when you weld, you really **** up the mechanical properties of the material. Also, a crack will stop at a hole, with a weld, it will carry on. You should heat treat all welds to return the material to it's optimum state. 

Nuclear subs have a reduced dive depth after a reactor change because the hull gets welded. There are loads of examples of why welding is crap, but on a low stress item like a car body, and non safety critical components, it's acceptable. You are better off bonding. Pop rivets are good if there are no material compatability issues.


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## mattysupra (Oct 31, 2008)

R32 Combat said:


> The aeronautical industry refer welding as a continuous defect. I know that when you weld, you really **** up the mechanical properties of the material. Also, a crack will stop at a hole, with a weld, it will carry on. You should heat treat all welds to return the material to it's optimum state.
> 
> Nuclear subs have a reduced dive depth after a reactor change because the hull gets welded. There are loads of examples of why welding is crap, but on a low stress item like a car body, and non safety critical components, it's acceptable. You are better off bonding. Pop rivets are good if there are no material compatability issues.




Yes, airplanes etc are pop riveted i belive due to they allow flex and expansion of the metals. on a race car you want to reduce this? no?


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## R32 Combat (Jan 29, 2004)

Aircraft are no rivetd to accommodate flex, it's just a better way. Ships flex, but they are welded. A weld is not the strongest joint and it 'will' stress fracture and fail before a rivet joint.


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## mattysupra (Oct 31, 2008)

R32 Combat said:


> Aircraft are no rivetd to accommodate flex, it's just a better way. Ships flex, but they are welded. A weld is not the strongest joint and it 'will' stress fracture and fail before a rivet joint.


so why bother welding then? 

Im not picking a argument here mate, just intrested in the logic. 

For instance most car panels (quarters/roof skins) are spot welded, why not pop rivet them? how come almost all race cars are seam welded? 

Odviously you cant pop rivet a ship due to water leaks.


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## GT-R Glenn (Nov 9, 2002)

Most aeroplanes I have seen are not made from an easily welded material....
When the SR71 was made, Im pretty sure they couldnt weld titanium properly
In fact to be pedantic aeroplanes are somewhat modular, presumably to swap out parts from RCM and or end of serviceable life etc:.
If a plane part fails they generally fall out of the sky and kill lots of people.

Oh dear my seam welded race car appears to have a small amount of rust appearing doesn***8217;t quite sound as disastrous to me 

In the old single seater car fab books they pop rivet monocoques so they don***8217;t melt the foam ...

Spot welding is faster and easier than riveting in a production based assembly setup.
As far as Im aware pretty much every mass produced car is spot welded using robots for all the majority of welds.
Yes some spots are done by hand.


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## R32 Combat (Jan 29, 2004)

Ships used to be riveted together with hot rivets. It gives a watertight seal, but again, when you beat the crap out of a piece of red hot metal, you change it's mechanial properties and they are suseptable to failure. Look at the Titanic. 
If you look at the F1 car, it's not welded together, it bonded. 
Welding is cosmetically better than riveting.

With the SR71, they had a job to machine Ti, yet alone weld it.


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## matty32 (Dec 18, 2005)

Just been speaking to Gio, its only a personal view point, but for the HipoGTR, it was given the same treatment on the frame as the Nismo Z Tune

as Gio says, (and tbh i agree) if your going to copy what Nismo thought was the best system for the flagship 34, then you cant go too wrong

once i drive it, and compare it to my previous 34, il let you all know


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## TSDAVE (Dec 12, 2010)

Just my few pennyworth, and not wishing to appear arrogant in anyway,this topic has been discussed for a long, long time,and being a retired Mechanical Design Engineer of 69, I would state the following points regarding methods of fixing.
1. Depends on the intended application i.e. what it has to do, to function in the designed manner.
2. How correctly, the chosen fixing is carried out.
3.Cost.

All the fixing methods known to man have their place, correctly used, in any application.


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## P3RV3RT (Aug 2, 2005)

R32 Combat said:


> Aircraft are no rivetd to accommodate flex, it's just a better way. Ships flex, but they are welded. A weld is not the strongest joint and it 'will' stress fracture and fail before a rivet joint.


If its a perfect weld it will not fracture, the parent metal will fail first, just the same as a bonded rivet joint.

All in, each has its poss and negs. Keep with the majority and go seam welded.


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## R32 Combat (Jan 29, 2004)

Seam weld is best.


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