Mixing metals, Oxidation ect.
Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Devonavar
Mixing metals, Oxidation ect.
I was planning on making a plate that will isolate the top of my case so that the power supply will be taking fresh air from the front, via 2 unused cd bays. I was just wondering, is it alright to use something like sheetmetal, will there be a reaction between the case metal and the sheetmetal? Oxidation, rusting ect. Is there a certain type of metal that i have to use, or do i have to put some kind of treatment on the metal?
-
- Posts: 262
- Joined: Sun Aug 11, 2002 3:26 pm
- Location: Worcester, UK
No, it should all be fine. Are you thinking of the problems people get when mixing copper and Alu in watercooling systems?
Why not make it out of card? Much easier and cheaper?
PS im doing something similar in mine - i have a 5V panaflo pushing air in at the front top and have taken the top two front drivebay covers out. Havent quite got round to making the divider yet tho hehe
Why not make it out of card? Much easier and cheaper?
PS im doing something similar in mine - i have a 5V panaflo pushing air in at the front top and have taken the top two front drivebay covers out. Havent quite got round to making the divider yet tho hehe
Im making a harddrive decoupler out of sheetmetal anyways, because they cant easily be decoupled with the standard hard drive rack. So I was gonna cut the hardrive rack out and make my own. A 120mm case fan under the power supply will handle all the exhaust and the power supply will just have to keep itself cool.
-
- Posts: 262
- Joined: Sun Aug 11, 2002 3:26 pm
- Location: Worcester, UK
-
- Friend of SPCR
- Posts: 228
- Joined: Sun Sep 29, 2002 9:05 pm
- Location: Powell River, BC, Canada
Hey Gaminggod, most computer cases are made out of...
The other common types of sheet metal are...
- satin-coat galvanized sheet steel - dull matte gray finish, good for painting up all pretty like
- chromed sheet steel - shiny chome color, mostly on really cheap cases
- aluminum - yup, needs no protective coating, paint optional / cosmetic except for marine environments
The other common types of sheet metal are...
- regular galvanized - crystalline pattern, think funace ducts, good stuff but ugly and doesn't paint well
- factory painted - metal roofing and siding, paint is not super hard so it scratches, white/brown for misc. flashing jobs is most common
-
- Posts: 53
- Joined: Fri Jan 24, 2003 3:45 pm
- Location: Los Angeles, CA USA
Re: Mixing metals, Oxidation ect.
Hi GG,GamingGod wrote:I was planning on making a plate that will isolate the top of my case so that the power supply will be taking fresh air from the front, via 2 unused cd bays. I was just wondering, is it alright to use something like sheetmetal, will there be a reaction between the case metal and the sheetmetal? Oxidation, rusting ect. Is there a certain type of metal that i have to use, or do i have to put some kind of treatment on the metal?
I was thinking of making a very similar system. One mod I was planning to do to the PSU was to (decoupled) mount the fan on the outside of the PSU case on the side of PSU that faces the drive bays. I also thought about mounting two fans at 6v on this side.
This will do a couple things to reduce noise. It place the airflow impedience on the side of the fan where it creates less noise. It also burries the fan inside to case to further lessen audible sound.
Of course the internal design of the PSU must allow airflow in this direction. It actally should be easier to design for this unidirectional airflow but the ATX spec has the air flow making a 90 degree turn within the PSU.
feel free to shoot this down entirely, but if you want to isolate the psu, then would it not be more simple to duct in some fresh air in to the psu? eg a tube running to a 80mm hole from the top of the case to the cpu intake. i ask more to find out the disadvantages of my suggestion than to offer a great tip, but you never know.
Thats basically what im doing, but the whole top of the case will serve as tube. and 2 empty cdbays will serve as the intake. Actually I was planing on doing something like what you said, but i was thinking more about ducting the air from the bottom of the case as I think less noise would escape that way, and im going to filter the bottom of the case anyways, because all of my intakes will be coming in from the bottom.
By having a junction of different materials you are creating a difference in electron potentials across the junction. Doing the calculation based on ground state potentials, it is safe to say that unless you have large amounts of exposed *pure* aluminum or tin, you are unlikely to have sensible degradation.
Aluminum and tin are extremely reactive metals. The reason why they do no seem to be, is that they quickly (order of minutes) form (atomically speaking) thick oxide layers. In the same vein, scratching of the pieces will not expose enough basal material to cause any problems.
But if you're looking for a good time, a fistful of ground rust and aluminum shavings with a magnesium fuse (thermite reaction) will melt a hole through a car engine, let alone your lovely new sonata. =)
Aluminum and tin are extremely reactive metals. The reason why they do no seem to be, is that they quickly (order of minutes) form (atomically speaking) thick oxide layers. In the same vein, scratching of the pieces will not expose enough basal material to cause any problems.
But if you're looking for a good time, a fistful of ground rust and aluminum shavings with a magnesium fuse (thermite reaction) will melt a hole through a car engine, let alone your lovely new sonata. =)
-
- Friend of SPCR
- Posts: 228
- Joined: Sun Sep 29, 2002 9:05 pm
- Location: Powell River, BC, Canada
Sorry B, I believe that needs to be black iron oxide, which I think has one extra oxygen per molecule, instead of the normal orange/brown stuff we call rust. FeO3 instead of FeO2. I think that cutting torch slag might do the trick, but I'm not 100% sure.B wrote:But if you're looking for a good time, a fistful of ground rust and aluminum shavings...
Actually, right and wrong. Household rust is a mixture of FeO and Fe2O3 (I'm sure you just forgot the 2 after Fe). The thermite reaction will proceed with either iron, but stoichiometry may be off resulting in some residual Al.crisspy wrote: FeO3 instead of FeO2. I think that cutting torch slag might do the trick, but I'm not 100% sure.
Not that this thread was about chemistry or that the original poster or anyone is going to try this. =)