Aluminum rivets

[JDFred]

22 hours ago, fredk said:

Taking last first I've had aluminium corrosion being blue away from any contact with leather. When #1 son was younger he shaved his head. At one medieval history event he wore an aluminium  chainmaille coif. (coif = head covering) It was a very hot day. He perspired a lot. When he took the coif off his head was covered in a pattern of blue circles. He told others that he was an ancient Briton!  (who used to paint blue patterns on their bodies)

I used brass washers as I didn't want to use steel. For that will give an electrolytic reaction*. And I didn't have aluminium

The leather straps were un-dyed veg tan

As far as I can remember the rivets diameter was less that 1/4 inch. Maybe 3/16" or 5/32"   If I can find them I could measure. 

I was given about 2000 of them. Gave loads away for model steam engine building and used about 50

 

* in motor vehicle building we put a layer of sponge rubber between the steel frame and the aluminium body work otherwise if both were in contact during corrosion the aluminium acts as a sacrificial metal corroding away quickly

PS; when setting the rivets and peening, I drilled a counter-sunk hole in a large steel plate and used that to support the round dome head

 

Thank you for the tool tip on setting them and also for indulging my random question.

[ClaimedVacancy]

Hello everyone. I’m a bit late to this conversation, but wanted to give some insight on alum rivets.

Ive used the Tandy “decorative” rivets with great success. They are annealed and have no temper which is good when swaging them. I’ve used them in restoration of many Swiss saddle packs, as they all originally came with alum rivets and often buckles, etc. 

Speaking of Swiss gear, take a look at Swiss army leathers such as saddle packs and ammo pouches. They all used aluminum rivets and studs. The oldest one I’ve restored was from 1917, and the aluminum rivets or studs were the last concern of mine. Zero corrosion, no breakage. They hold up remarkably well, and the packs from this time are all fairly hard used. 

Since the Tandy alum rivets are annealed, this puts them in the 1100 category of aluminum with no alloying agents. This is good because it reduces the amount of corrosion potential. If they were say 7075 series aluminum, you would have a greater corrosion risk. And mixing metal parts will give you mixed results depending on how dissimilar they are (steel vs aluminum for example).

When it comes to brass, followed by copper, verdigris will be an issue especially if the item isn’t used for some time, and an electrolyte (water) is present in the air in high amounts. The verdigris is a reaction with the tannins against the metal, and aluminum does not react to the tannins. The only staining you will have is greying from the aluminum essentially being polished from abrasion by the leather. 
 

I hope this is helpful! I’ve been in aviation for over a decade, working with aluminum extensively. I’ve also attached two example pictures of aluminum fasteners from Tandy, along with a verdigris issue on a pack I’m restoring currently. 

[JDFred]

20 hours ago, ClaimedVacancy said:

Hello everyone. I’m a bit late to this conversation, but wanted to give some insight on alum rivets.

Ive used the Tandy “decorative” rivets with great success. They are annealed and have no temper which is good when swaging them. I’ve used them in restoration of many Swiss saddle packs, as they all originally came with alum rivets and often buckles, etc. 

Speaking of Swiss gear, take a look at Swiss army leathers such as saddle packs and ammo pouches. They all used aluminum rivets and studs. The oldest one I’ve restored was from 1917, and the aluminum rivets or studs were the last concern of mine. Zero corrosion, no breakage. They hold up remarkably well, and the packs from this time are all fairly hard used. 

Since the Tandy alum rivets are annealed, this puts them in the 1100 category of aluminum with no alloying agents. This is good because it reduces the amount of corrosion potential. If they were say 7075 series aluminum, you would have a greater corrosion risk. And mixing metal parts will give you mixed results depending on how dissimilar they are (steel vs aluminum for example).

When it comes to brass, followed by copper, verdigris will be an issue especially if the item isn’t used for some time, and an electrolyte (water) is present in the air in high amounts. The verdigris is a reaction with the tannins against the metal, and aluminum does not react to the tannins. The only staining you will have is greying from the aluminum essentially being polished from abrasion by the leather. 
 

I hope this is helpful! I’ve been in aviation for over a decade, working with aluminum extensively. I’ve also attached two example pictures of aluminum fasteners from Tandy, along with a verdigris issue on a pack I’m restoring currently. 

Thanks for the info.  I never thought about different alloys reacting in different ways, stuff like that is always good to know.  It would seem that their service life is pretty good if they hold up for over a hundred years.

[ClaimedVacancy]

@JDFred

Certainly! Aluminum is pretty remarkable. It only becomes problematic with contact to dissimilar metals, prolonged water contact, and salts. Or a combination of those.
 

If you ever give them a go and need different head sizes, i would stick with the annealed versions. If they are tempered, they will toenail bad inside the leather since the walls of the hole do not have support against the compression of the rivet. Ive tried mil spec aircraft rivets, and its always a disaster in my applications. I would think if you have enough support around the whole, you could reasonably work with tempered alum rivets on leather. 
 

If you are in need of using different metals for the application, check the galvanic corrosion charts to see if they are compatible, too. Stainless and alum should be okay for a good bit, but ill say that depending on the size difference of the parts, and how far apart on the chart they are, the alum rivets would fail over time. 

Edited Friday at 01:00 AM by ClaimedVacancy