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Rivets - What size used in ultima's?
Duncan_P - 27/9/07 at 10:04 AM

After deciding to go with some large head rivets for my pannelling i made the fatal mistake of looking through my magazines

I am currently rather taken with the look achieved in Ultimas by using lots of fairly small rivets

See pic here

Does anyone know what size of rivets are used?

And is this a rather stupid idea?

RazMan - 27/9/07 at 10:10 AM

I think you will find that the Ultima boys use the same 3mm rivets as we do for side panels and something a bit heftier for the floor - 5mm with large heads are commonly used.

oadamo - 27/9/07 at 10:12 AM

for the floor to the box section do you use alloy or steel rivets whats best.
soz for the hijack.
adam

worX - 27/9/07 at 10:17 AM

I would of agreed with Razman, but looking at the photos I would say that they are a tiny bit bigger than 3mm...

I know there is a size in between 3 and 5 mm - I think there is a straight 4mm size, but I also seem to recall that there might be a slightly odd size like 4.3mm that is more common - but could be totally wrong on that!

Adam - most people just use normal ali rivets in the floor - albeit in the 5mm size variety...

Steve

stevec - 27/9/07 at 10:20 AM

Please stop posting pictures of Ultima's.
It does my head in cos I cant have one, they soooooooo lovely.
Steve.

Duncan_P - 27/9/07 at 10:21 AM

Ok thanks guys, that is pretty much what I was thinking. But its nice to have some confirmation before ordering a couple of hundred rivets (hmm maybe this isn't such a good idea )

Duncan_P - 27/9/07 at 10:23 AM

quote:
Originally posted by stevec
Please stop posting pictures of Ultima's.
It does my head in cos I cant have one, they soooooooo lovely.
Steve.


But they are soooo svelt..... and the noise

Sorry Steve

02GF74 - 27/9/07 at 10:25 AM

it wouldn't surprise me if thre were metric and imperial rivet body diameters.

just to hijack further, is there any info. about rivet size (body & head diameter) and spacing to hold a load - in other words how to work out size and number of rivets to use to hold panels say?

iank - 27/9/07 at 10:38 AM

Standard sizes are 3.2, 4.0 and 4.8
I seem to remember reading somewhere that 3.2 is actually old imperial size (1/8" ) metricated. Maybe 4.8 is the same.

[Edited on 27/9/07 by iank]

RazMan - 27/9/07 at 11:00 AM

Rivet spacing depends on the panel thickness imo. If you space them too far apart the panels tend to 'pucker' as the PU adhesive offers some resistance. I found that 75mm spacing was about right on my side panels, with 100mm for the floor (but with large headed rivets)

edit** Steel ones will offer the best strength but when you use PU to bond the banels, some people reckon you don't really need the rivets anyway.

[Edited on 27-9-07 by RazMan]

02GF74 - 27/9/07 at 11:20 AM

^^^ I was actullay thinking of load bearing panels such as floor - I guess it is not simple answer since it wold depend how bit the panel is and where the wight is and so on.


yet another twist to the thread .... but instead of using rivets, could you used riv-nuts instead? I think these could be lighter since you don't have the metal pin stuck in them but will they be as strong? (or go to a larger diameter rivnut?)

MikeRJ - 27/9/07 at 11:30 AM

quote:
Originally posted by 02GF74
yet another twist to the thread .... but instead of using rivets, could you used riv-nuts instead? I think these could be lighter since you don't have the metal pin stuck in them but will they be as strong? (or go to a larger diameter rivnut?)


Rivnuts would not be lighter since you have to take into account the screw. Also rivnuts require much larger holes to be drilled into the box section, which could compromise the strength if you have a lot of them.

Paul TigerB6 - 27/9/07 at 11:53 AM

Available imperial rivets:-

2.4mm or 3/32 inch
3.2mm or 1/8 inch
4.0mm or 5/32 inch
4.8mm or 3/16 inch
6.4mm or 1/4 inch

02GF74 - 27/9/07 at 12:57 PM

quote:
Originally posted by MikeRJ
quote:
Originally posted by 02GF74
yet another twist to the thread .... but instead of using rivets, could you used riv-nuts instead? I think these could be lighter since you don't have the metal pin stuck in them but will they be as strong? (or go to a larger diameter rivnut?)


Rivnuts would not be lighter since you have to take into account the screw. Also rivnuts require much larger holes to be drilled into the box section, which could compromise the strength if you have a lot of them.


worng - I did not mention fitting the screw, just using the riv nut like a rivet - the threaded part allows it to be fitted without leaving the metal pin behind.

agreed the hole may be larger but if you use say a 3 mm riv nut - probalby 5 mm hole cf 4 mm rivet - depends whcih one is stringer I guess. A 5 or 6 mm hole isn't going to compromise a 25 mm chassis tube much more than a 4 mm rivety I wouldn't have thought.

'twas just a thought to save a bit of weight, but would be a bit more £££

DaveFJ - 27/9/07 at 12:58 PM

This is a good guide. IIRC I used 40mm staggered pitch on the 4.8mm rivets in my floor and 35mm staggered pitch on the 3.2mm rivets everywhere else. Staggering the rows makes for a much stronger join.




[Edited on 27/9/07 by DaveFJ]

02GF74 - 27/9/07 at 01:14 PM

quote:
Originally posted by DaveFJ
Staggering the rows makes for a much stronger join.



eh? do you mean stagering the rivets so they are not is a striaight line, making the spacing between them different or?

surely on the edge of one a you only have one row so how can you stagger?

or is it saying if you have two sheets butting, then the rivets are staggered i.e. the rivets o nthe second sheet place in between the rivets on the first? that wuld make sense.

(a piccy is worth a 100,000 words here)

nick205 - 27/9/07 at 01:17 PM

quote:
Originally posted by RazMan

edit** Steel ones will offer the best strength but when you use PU to bond the banels, some people reckon you don't really need the rivets anyway.

[Edited on 27-9-07 by RazMan]



I've pondred on this before about PU adhesive being strong enough to hold the floor without rivets.

My thinking is that the PU is actually the ally sheet to the paint or powder costing. The join is therefore only as strong as the paint adhesion to the steel chassis. In my case the "specialist" chasis Black paint I used is cr8p and peels off quite easily so the floor would drop off pretty quick without the rivets in place (4.0mm @ 40mm spacing).

DaveFJ - 27/9/07 at 01:32 PM

Sorry, I mean having the layout staggered so the rivets dont form one line like this:

@....@....@....@....@....@....@....@....@

this causes the strees in the sheet to be focused along a single line which can lead to cracking and fretting of the rivets.

if you stagger the lines like this (just about possible when attatching sheet to 25mm square tube):

@.......@.......@.......@.......@.......@.......@
.....@.......@.......@.......@.......@.......@

it forms a stonger joint.

ignore the .....'s they need to be there or the text autoformats the spaces out and ruins the diagram

RazMan - 27/9/07 at 01:39 PM

quote:
Originally posted by 02GF74
'twas just a thought to save a bit of weight, but would be a bit more £££


I don't think they would be as strong as 'real' rivets because their strength relies on the bolt keeping the rivnut squeezed against the panel.
Also you would end up with a 3mm ish hole that would need to be plugged.

Just a theory though

[Edited on 27-9-07 by RazMan]