Mixing metal types (aluminum head with brass, stainless or titanium handle)

AZBronco · Nov 7, 2021

I'm trying to find out if there are any downsides to mixing metals. Specifically, I have an aluminum hawk and am wondering about using the head on a heavier handle. I was able to find some information specific to combining aluminum with stainless and there are two concerns. One is you have to be careful not to overtighten the head, stripping the screw. Second is that, over time, water + aluminum + steel = corrosion (no idea how long that would take with a razor).

Does anyone here understand metals enough to explain what would happen using an aluminum head on various metal handles? Would brass or titanium be a better choice to pair with aluminum than than steel?

Thanks!

kingfisher · Nov 7, 2021

Not a metallurgist, but titanium is pretty much non-reactive, and therefore would definitely be a safe choice.

hairless wonder · Nov 7, 2021

I can't speak to those properties, but I would also suggest that using heavier handles will likely change the balance of the razor.

rbscebu · Nov 7, 2021

Your biggest concern when mixing metals would be electrolysis. Brass (copper/zinc alloy) and steel (including stainless steel) react by the steel causing the decomposition of the zinc in the brass to zinc oxide. This then leaves you with a porous copper. The decomposition of the zinc is accelerated by the presence of an electrolyte.

hairless wonder · Nov 7, 2021

rbscebu said:
Your biggest concern when mixing metals would be electrolysis. Brass (copper/zinc alloy) and steel (including stainless steel) react by the steel causing the decomposition of the zinc in the brass to zinc oxide. This then leaves you with a porous copper. The decomposition of the zinc is accelerated by the presence of an electrolyte.

And that's one of the reasons why @rbscebu shaves with a straight razor.

Yuritau · Nov 9, 2021

You can use whatever combination you want of these metals together without issue, as long as you don't leave them in contact with each other after shaving. Drying the parts off is also recommended. The reactions don't move fast enough to have significant effects during a shave.

linty1 · Nov 10, 2021

I have a aluminum hawk on a titanium handle and so far so good? I also have a spacer/washer in between the two (I bought the head used and it came with one and I've just kept in on, no particular reason beyond that). But in terms of the threads etc, they still thread as good as when I got them with no visible discoloration etc.

AZBronco · Nov 10, 2021

linty1 said:
I have a aluminum hawk on a titanium handle and so far so good? I also have a spacer/washer in between the two (I bought the head used and it came with one and I've just kept in on, no particular reason beyond that). But in terms of the threads etc, they still thread as good as when I got them with no visible discoloration etc.

I tried my Ti handle on the Hawk this morning to see if it would thread. It did with no issues. I didn't shave with it (went with a straight today)--but I did play around a little and it seems like balance is OK.

Halfblade · Dec 3, 2021

AZBronco said:
I'm trying to find out if there are any downsides to mixing metals. Specifically, I have an aluminum hawk and am wondering about using the head on a heavier handle. I was able to find some information specific to combining aluminum with stainless and there are two concerns. One is you have to be careful not to overtighten the head, stripping the screw. Second is that, over time, water + aluminum + steel = corrosion (no idea how long that would take with a razor).

Does anyone here understand metals enough to explain what would happen using an aluminum head on various metal handles? Would brass or titanium be a better choice to pair with aluminum than than steel?

Thanks!

The issue that arises when two dissimilar metals are in contact with each other while connected with an electrolyte is called galvanic corrosion.

For the conditions in which galvanic corrosion can take place to be present, three things are necessary

The electrochemical potentials of both metals should be different & the difference should be significant.
Both metals should be in contact with an electrolyte.
The metals have to be in electrical contact with each other and with the electrolyte.

If any of these three conditions are not met, galvanic corrosion cannot take place.

Taking point 2 first: - I strongly doubt that the moist air that is found in the environment of a washroom can be considered an electrolyte, unless you are near the sea & salty water is present in fine droplets in the air. Areas where the water is hard could also leave deposits on the razor, & before evaporation there could be some corrosion, especially if you dont wash the hard water off with some distilled water or by dipping in rubbing alcohol. But if you have soft water & are not near the sea, you shouldn't face a problem. To further ensure that, leave the razor where it does not stay wet. For example, if leaving it in a mug, the mug should have a hole for water drainage. Or you could keep your razor outside your washroom.

With regard to point 3: - Razorock's Hawk razor has a anodized coating. If the coating is not compromised (by a fall, or scratch or something similar) then corrosion cannot take place, because it would not be exposed to air.
In addition to that, if you electrically separate the two metals, again there would be no corrosion. The easiest way to do that would be to use teflon tape on the threads, & use sticky plastic tape or washer stuck to the bottom of the baseplate. Your handle is then electrically isolated from the handle, preventing possible galvanic corrosion. Simple.

With regard to point 1, an aluminium head is sufficiently dissimilar in potential to stainless or brass that corrosion is possible.
However, zinc is even more likely to face galvanic issues, so if you can get your hands on a few zinc washers or foil, you can put that in between the handle & baseplate. The zinc would slowly erode, saving both head & handle. Of course, that assumes that you have not electrically isolated the head, & you are in a sea air atmosphere or the razor has been dipped in hard water which has not been rinsed off.