View Full Version : Lets talk rivets - Aluminum vs Stainless Zinc coated
Is there a problem with using stainless rivets in aluminum panels? I like the look of the stainless rivets, before I order them I want to make sure there are no problems mixing aluminum panel with a stainless rivet? I was just considering doing the engine compartment in stainless and the rest of the car with the supplied FFR aluminum rivets.
Vspeeds
06-07-2020, 02:53 AM
Good question Travis and I don’t have an answer. And I’m not a metalurgist but I know in general that dissimilar metals in contact with each other along with an electrolite/ moisture will have a negative reaction in the form of corrosion. But since were talking about small rivets on a non structural aluminum panel, I too wonder if there would be a problem. I also like the looks of stainless rivets.
OVCobra
06-07-2020, 06:54 AM
As noted by Vspeeds, the presence of stainless can/will create 2 galvanic corrosion cells; rivet to panel (stainless-aluminum) as well as rivet to frame (stainless-carbon steel). As such, there is a potential of both panel corrosion as well as frame corrosion.
Using aluminum rivets there is no galvanic cell between the panel and rivet and while there is a cell between rivet and frame the rivet would be attacked not the frame.
Having said this, there must be an electrolyte to create corrosion and unless you intend to drive this in the winter (moisture + salt), the risk is fairly low.
The only other possibility I can think of would be excessive panel deformation/dimpling of the aluminum panels caused by the higher compression from the stainless rivets...maybe try it on some scraps to find out?
Good luck
rich grsc
06-07-2020, 07:36 AM
I'm pretty sure that's not the case. SS isn't used to make batteries, in fact it's used in corrosive environments all the time because it's non-reactive. It's used on boats because it doesn't corrode.
mike223
06-07-2020, 09:03 AM
The only problem I see is that the stainless rivets are much more of a pain in the neck to drill out.
I see no advantage to them - just more of a problem to drill them out if that were ever required.
j.miller
06-07-2020, 09:46 AM
[QUOTE=mike223;414695]The only problem I see is that the stainless rivets are much more of a pain in the neck to drill out.
I see no advantage to them - just more of a problem to drill them out if that were ever required
YOU ARE CORRECT SIR ! If you ever have to take them out you have a bigger chance of making a mess. That being said....if you like the look, go for it. The rivets aren't really structural …..just put in twice as many and don't look back.
Jeff Kleiner
06-07-2020, 10:37 AM
The only problem I see is that the stainless rivets are much more of a pain in the neck to drill out.
I see no advantage to them - just more of a problem to drill them out if that were ever required.
And a whole heck of a lot harder to pull when you install them!
Jeff
The only problem I see is that the stainless rivets are much more of a pain in the neck to drill out.
I see no advantage to them - just more of a problem to drill them out if that were ever required.
Agree!
I encourage you to listen to Mike's advice but if you tend to learn by hard knocks, by all means use SS rivets. SS rivets have a place but IMO, a very limited one. I've drilled out my share of SS rivets and avoid using them wherever I can.
BEAR-AvHistory
06-07-2020, 10:51 AM
Will pile on as someone currently drilling out some trunk floor access panel rivets. Very happy with aluminum.:)
Hotyacht
06-07-2020, 05:07 PM
I'm pretty sure that's not the case. SS isn't used to make batteries, in fact it's used in corrosive environments all the time because it's non-reactive. It's used on boats because it doesn't corrode.
Incorrect! Stainless fastenings in aluminium is a serious problem in the marine environment and great care must be taken to use some form of insulation between the two metals - the aluminium will corrode very rapidly otherwise. The stainless will be fine, but the aluminium will look like S***e! Stainless steel and aluminium are at opposite ends of the galvanic scale which is where the problem lies.
It is likely to be less of an issue in a car unless it gets wet, however why would you want to introduce the problem? And as others have said, you are going to make you life more difficult popping the rivets and then when you have to drill them out again, and chances are you WILL have to drill some of them out again.
If you really have to have stainless rivets then you would be well advised to use some form of insulation - example would be to powdercoat, or nyalic the alloy panels first, but don't re-drill the holes after coating otherwise you will expose the bare aluminium again.
Appreciate all the feedback, I will just keep it simple and stick with aluminum.
Chris @ Forma
06-07-2020, 10:11 PM
Hotyacht is correct regarding galvanic corrosion between aluminum and stainless. As for the appearance, I take the position that rivets should not be seen. I prefer powder coated aluminum and my fall back color of choice is called silver artery. https://www.prismaticpowders.com/shop/powder-coating-colors/PVS-3014/silver-artery the big advantage as it hides stone chips etc. Unfortunately the rivets look like silver warts on this panels. I found an outfit in southern Texas that paints our rivets. I don't remember who they are off the top of my head, however, they charge something ridiculously small something like $0.03/rivet. And I think their minimum was $60. If you are interested, please PM me and I'll research where we buy them.
Hotyacht is correct regarding galvanic corrosion between aluminum and stainless. As for the appearance, I take the position that rivets should not be seen. I prefer powder coated aluminum and my fall back color of choice is called silver artery. https://www.prismaticpowders.com/shop/powder-coating-colors/PVS-3014/silver-artery the big advantage as it hides stone chips etc. Unfortunately the rivets look like silver warts on this panels. I found an outfit in southern Texas that paints our rivets. I don't remember who they are off the top of my head, however, they charge something ridiculously small something like $0.03/rivet. And I think their minimum was $60. If you are interested, please PM me and I'll research where we buy them.
That is the exact same powder coat I am using on all my panels. My plan is to order some black alum rivets from Summit Racing, seems like the easiest way to go,
https://www.summitracing.com/parts/sum-abs4246urr-2
There are a lot of speed parts suppliers that cater to racers and carry colored rivets. Even McMaster-Carr carries them. If you look at several suppliers you may find an off the shelf color that comes close to matching your powder coat color.
I do have a question about the black Ultimate Rivets from Summit. They offer a 1/8" x 1/4 head, 1/2" long rivet. I don't see any other lengths available only a 3/8" head which I think is too large. Can I use the 1/2" length for all my panels? Even the alum to alum? I was going to order 1000 of them, figured that should cover everything?
Thank you
Look at the grip range and at the thickness of materials you want to join. The ones you linked to have a grip range of .063" to .375" which should handle most tin work on a typical race car build. On fastening very thin panels you would want to use a back-up washer on the back side so you might consider buying a box to have around. But you wouldn't get too far on fiberglass with these short rivets and in fact, it's better to use rivets made for plastics when riveting fiberglass: https://www.mcmaster.com/rivets/rivets/blind-rivets-for-soft-materials-6/
Look at the grip range and at the thickness of materials you want to join. The ones you linked to have a grip range of .063" to .375" which should handle most tin work on a typical race car build. On fastening very thin panels you would want to use a back-up washer on the back side so you might consider buying a box to have around. But you wouldn't get too far on fiberglass with these short rivets and in fact, it's better to use rivets made for plastics when riveting fiberglass: https://www.mcmaster.com/rivets/rivets/blind-rivets-for-soft-materials-6/
I just want a rivet size for all the panels on my build. I believe all the panels on the mk4 are .040. Assuming the .063" to .375" will take care of all of panels? The only thicker panel I have is the firewall and center console which is .090
edwardb
06-08-2020, 05:59 AM
I just want a rivet size for all the panels on my build. I believe all the panels on the mk4 are .040. Assuming the .063" to .375" will take care of all of panels? The only thicker panel I have is the firewall and center console which is .090
The "ultimate rivets" that Summit sells (and similar available elsewhere) have a very wide grip range. Also often called multi grip rivets. I've used them quite a bit and they work as advertised. Nice rivets and pull and work really well. The only problem with them is that large collapsing back side makes a pretty big "blob" on the other side. That's not a problem when installed into frame tubes or other locations where the back appearance and/or clearance isn't an issue. But I'd be careful using them for panel to panel like in the footboxes. Look fine from one side. But the back will be pretty tall and messy for your insulation, carpet, etc.
The "ultimate rivets" that Summit sells (and similar available elsewhere) have a very wide grip range. Also often called multi grip rivets. I've used them quite a bit and they work as advertised. Nice rivets and pull and work really well. The only problem with them is that large collapsing back side makes a pretty big "blob" on the other side. That's not a problem when installed into frame tubes or other locations where the back appearance and/or clearance isn't an issue. But I'd be careful using them for panel to panel like in the footboxes. Look fine from one side. But the back will be pretty tall and messy for your insulation, carpet, etc.
Paul what length would you recommend for the footbox alum to alum panels? Assuming the 1/4" head size will work for everything? This was my concern about using a 1/2" long rivet in the footbox area. Assuming this is why FFR sends shorter rivets - for footbox panels?
edwardb
06-08-2020, 01:54 PM
Paul what length would you recommend for the footbox alum to alum panels? Assuming the 1/4" head size will work for everything? This was my concern about using a 1/2" long rivet in the footbox area. Assuming this is why FFR sends shorter rivets - for footbox panels?
Yes, the shorter ones are for the aluminum to aluminum panels. The grip ranges printed on the labels are pretty accurate. Use accordingly.