Copper and Aluminum Don't Mix

[polarcupz]

I have been reading around, and have found many articles and testimonials that say not to mix copper and aluminum. The heat sinks for the MHS are copper, whereas the MHS are aluminum. Won't this cause corrosion after time in the lightsaber? Sorry if this is in the wrong section. I couldn't decide whether to put it here or in misc.

[FenderBender]

I havent seen any adverse effects in the last couple of years of my use of the MHS system. I think that in a different application, that might apply but the heatsink is just sandwiched between the Blade Holder and the hilt/choke etc. and not in a high stress environment.

I wouldn't worry about it.

[Obi-Dar Ke-Gnomie]

If there was moisture, or an acidic environment, then you could get some galvanic corrosion, but for what we do, it's fine to use them together. Just don't get your saber wet. ;-)

[Dominious]

Ok that helps a good deal but what about us poor souls that live in hot humid places like the US gulf coast states? Average daily forcast has been 94f and 90+% humidity.

[dj2rbo]

I wouldnt worry about it... if you want to keep worrying you can. but you will come up with a thousand different things to worry about..... so its totally up to you.

[Jedi-Loreen]

http://ecx.images-amazon.com/images/I/217MogkJ%2BiL._SL500_AA300_.jpg ;)

[Arkhan]

Many computer heatsinks use a copper core and aluminum fins with nary a problem.

Some dissimilar metals will cause corrosion in the short term.

In the case of Aluminum and Copper Electrical wiring, different thermal expansion co-efficients would cause loose connections and potentially, fires.

That's why houses don't use aluminum electrical wiring unless they have outlets and connectors designed for use with aluminum. It was a problem back in the 60s and 70s, and houses of that era.

Fear not.

[polarcupz]

Thanks for the replies! I will try not to get any of my sabers soaked. Oh and what about a lightsaber shroud made of copper? I have been thinking about doing this with a brass sink tube "buffer" so to speak so they don't touch. I will have to post on a different thread when I get around to making the shroud.

[FenderBender]

Dude, really. DONT WORRY ABOUT IT. I lived in FL for 26 years, wasn't a problem when we lived there. Copper shrouds wouldn't cause any problems and you shouldn't NEED a brass buffer unless you want it aesthetic reasons.

[polarcupz]

Okay, no worries then. Thanks everyone for your help!

[Obi-Dar Ke-Gnomie]

you shouldn't NEED a brass buffer unless you want it aesthetic reasons.

Because, we all know that copper and brass look good together... ;)

http://img.villagephotos.com/p/2005-12/1126239/enigma_1.jpg

[Skottsaber]

Because, we all know that copper and brass look good together... ;)

Nah, it's just the knowledge that there is a CF in there :lol:

[polarcupz]

Corrosion Found.

I have corosion between my Lux V and my copper heatsink. Any suggestions?

[Shadar Al'Niende]

give up?



seriously... thermal tape? don't know what else to tell you...

[polarcupz]

give up?

I will NEVER give up. There must be a way. Thermal tape might work. I haven't tried it yet, but it would keep the two apart. I hadn't opened the saber up in a while(1 yr maybe?).

[FenderBender]

For a while, we used thermal grease. We opened up a saber we did a year ago for an upgrade and there was no corrosion. The heatsink was a little tarnished, but no evident deteriation otherwise. This thread really is pointless to continue. IT'S NOT A BIG DEAL.

[Skottsaber]

Corrosion Found.

I have corosion between my Lux V and my copper heatsink. Any suggestions?

You're sure its not just the patina of the heatsink?

[polarcupz]

I will try to get a pic when I get home. Oh and thanks fender, that is really nice of you, very supportive. Whatever. It is all over the bottom of the lux V, not as much on the copper...but that is how the corrosion is supposed to work (copper will eat away at the aluminum).

If this thread should not be continued I will let it die, along with my lux V.

[Jay-gon Jinn]

I will try to get a pic when I get home. Oh and thanks fender, that is really nice of you, very supportive. Whatever. It is all over the bottom of the lux V, not as much on the copper...but that is how the corrosion is supposed to work (copper will eat away at the aluminum).

If this thread should not be continued I will let it die, along with my lux V.
I've been using the copper heatsinks in my personal MHS sabers for two years, and have not had an issue with corrosion in any of them, nor have any of my led's died. i've always ued either the thermal paste he mentions, or the star-shaped thermal tape Tim sells here in the store when I mount the led's. What Fender says is true...it's really not a big deal. Do you really think if it wasn't safe, that Tim would be selling copper heatsinks in the first place? ;)

Aluminum and cast iron don't mix either, yet auto manufacturers have been using aluminum cylinder heads on cast iron engine blocks for decades....the reason they can do it? The head gaskets separate the two metals enough that the corrosion never happens. It's the same with the thermal tape and your led's aluminum base plate.

[Darth Xusia]

I've been using the copper heatsinks in my personal MHS sabers for two years, and have not had an issue with corrosion in any of them, nor have any of my led's died. i've always ued either the thermal paste he mentions, or the star-shaped thermal tape Tim sells here in the store when I mount the led's. What Fender says is true...it's really not a big deal. Do you really think if it wasn't safe, that Tim would be selling copper heatsinks in the first place? ;)

Aluminum and cast iron don't mix either, yet auto manufacturers have been using aluminum cylinder heads on cast iron engine blocks for decades....the reason they can do it? The head gaskets separate the two metals enough that the corrosion never happens. It's the same with the thermal tape and your led's aluminum base plate.

Yeah... what he said. ;)
Jay always has the most thorough explanations.

[Arkhan]

If you feel you're getting true corrosion, as opposed to normal oxidation of aluminum and copper, then I would try some sort of barrier between the two.

As mentioned, the double-sided thermal tape works pretty well (not as well as thermal compound, but.....).

Is it possible that your led is inadvertantly grounded to the copper heatsink, via the aluminum star base? that would generate a potential, and vastly increase the likelihood of corrosion between dissimilar metals.

Any part of your "+" or "-" leads that aren't insulated, touching the aluminum star base, could provide a path for current. You would hope to notice the extra drain, but maybe not.

The newer Lux rebels are electrically isolated from the star base, but IIRC, the older LuxI, LuxIII, LuxV, etc may very well not have been. That would put the base as a ground path, any touching copper as a ground path, and if some other part of your saber hilt were also grounded, you'd get current flow through the starbase and copper, instead of just through the LED.


Thoughts to ponder

[FenderBender]

I will try to get a pic when I get home. Oh and thanks fender, that is really nice of you, very supportive. Whatever. It is all over the bottom of the lux V, not as much on the copper...but that is how the corrosion is supposed to work (copper will eat away at the aluminum).

If this thread should not be continued I will let it die, along with my lux V.


I WAS supportive. The first time. After that it just seems like problem mongering where this isn't one. It would probably shock you at the numbers of MHS systems that Tim has sold with copper heatsinks over the years. This hasn't been a problem. At all.

Like mentioned before, if you have corrosion, there is something wrong that YOU'RE doing.

[Skottsaber]

It would probably shock you at the numbers of MHS systems the Tim has sold with copper heatsinks over the years.

I was going to say:

Don't you mean that Tim has sold?
But then I realised there was no error of grammatical here :mrgreen:

[FenderBender]

Yes, while The Tim should be mentioned with proper respect, I did mean to put that:D

[polarcupz]

Is it possible that your led is inadvertantly grounded to the copper heatsink, via the aluminum star base? that would generate a potential, and vastly increase the likelihood of corrosion between dissimilar metals.

Any part of your "+" or "-" leads that aren't insulated, touching the aluminum star base, could provide a path for current. You would hope to notice the extra drain, but maybe not.

The newer Lux rebels are electrically isolated from the star base, but IIRC, the older LuxI, LuxIII, LuxV, etc may very well not have been. That would put the base as a ground path, any touching copper as a ground path, and if some other part of your saber hilt were also grounded, you'd get current flow through the starbase and copper, instead of just through the LED.


Thoughts to ponder



It must be a short then. I haven't really picked the saber up in a long time, so I wouldn't have really noticed the extra drain. Thanks so much!

[Arkhan]

Nobody wants to see your LED get eaten alive and destroyed. Just because something *rarely* occurs, doesn't mean it isn't happening to you right now.

That it *is* happening should point to something wierd, or not quite right.

I would definitely check to ensure there is no grounding issues with your led/heatsink assembly and the rest of the saber.

If everything is correct, you should NOT be able to measure voltage between the heatsink and the "-" terminal of the battery regardless of saber being ON or OFF.

EDIT:

I looked at www.luxeonstar.com The Lux1, Lux3, Lux5 *all* specify that they do not have an electrically isolated base, and steps must be taken to ensure electrical isolation between the star base and the rest of the saber. The Rebel Star base is isolated, as was the K2 star.

End EDIT:


Fenderbender or others have probably diagnosed 50 times more saber related problems than I have, so if I'm leading you on a wild goose chase, I hope they'll step in and provide some gentle correction.

[FenderBender]

No, you are pointing to a plausable explaination. My point was that the initial post was about the MHS system being faulty because of the mixed materials was bogus. When things like this happen, there IS a problem, but it's not the MHS. The electrical problem is a good place to start, especially if there is an in hilt recharge set up and there are bare wires touching the star. IIRC, it was mainly the red family of LUX's that had the isolation issues, but that doesn't mean that the whole line couldn't have them as well.

[polarcupz]

It is just ironic that the original question turned into all of this. Isn't it funny how things work. It is corrosion but not likely that it is the fault of only the two metals.

Sorry guys for all of the trouble and thank you for your help. I had this saber completely apart, and was reworking the wiring when I noticed it. I will have to check the connections.

[Arkhan]

as I pointed out earlier, thousands upon thousands of computer CPU heatsinks have been sold that combine a copper core with aluminum fins. The two are tightly interfaced and that precludes any sort of electrical isolation.

That thousands and thousands of these heatsinks have not corroded and destroyed said systems is a pretty good indicator that simply putting aluminum and copper in contact with each other is not a bad idea.

The MHS heatsink design is not a recipe for disaster.

That this person *is* seeing corrosion should point to something wierd, and not support a claim that the MHS system "is bad" with its heatsink materials.

[polarcupz]

That this person *is* seeing corrosion should point to something wierd, and not support a claim that the MHS system "is bad" with its heatsink materials.

I wasn't claiming that anything is wrong with the heatsink or the MHS parts or the materials. I was just asking a question in the beginning. The connection was MY fault on the lux v thus the corrosion. Thanks for your advice.

[Arkhan]

You didn't drop any accusations, perhaps we read some in.

I hope you have your problem figured out with the star base and your saber continues to bring years of geeky enjoyment to you and yours.

I'll file away "corrosion due to grounding of star base" into my bank of "wierd stuff that can happen sometimes, so don't dismiss it out of hand"

[Ronan]

I'm always amazed how quickly some people jump on others that seek help...

To the OP check your wiring, maybe theirs something putting current through the copper heatsink.

Edit: Seems i have crossed FB's path, and i do apologize. No harm meant, just pointing out something that disturbed me.

[FenderBender]

Way to go stirring up trouble. No one "jumped" on the OP. He seemed to be worried about the combination of materials (unwarranted) and we told him to look elsewhere for the issue. Everything was just fine until YOU started throwing accusations around.

[Ronan]

Way to go stirring up trouble. No one "jumped" on the OP. He seemed to be worried about the combination of materials (unwarranted) and we told him to look elsewhere for the issue. Everything was just fine until YOU started throwing accusations around.

I personally have nothing against you, but you come off really strong in your posts.

Maybe try decaff? I know it did wonder for me :)

[Shadar Al'Niende]

Try decaff.

You people really don't get what kind of forum you joined do you...

[Ronan]

You people really don't get what kind of forum you joined do you...

No, please explain for 'us people'...

Yes i am new here, i found the forum after making a couple purchases at TCSS.

I see a lot of individuals helping people in need and then i see the odd individual(s) that seems to take pleasure at taking stabs at people in need.

Which to me is quite rude.

Now i do understand this is 'the internet' and this forum is a little niche for some people, but i do not see how because of that it's acceptable to comport one-self poorly.

Now i do want to make this clear: I do not have anything against anyone, and i am not stirring up trouble, but just pointing out something that disturbed me and i really have nothing else to say about this. (Like i said, we have better things to do than internet fights...).

Cheer and MTFBWY :)

[Shadar Al'Niende]

What you need to realize is that this is a Do It Yourself forum. This is a forum to collect and distribute information for those who want to learn "how to" do things in this hobby. Simply by the nature of what this forum is, people MUST be willing to learn, and by that i mean look for and assimilate information. Some people here take that one step further and spend their time and money to fund innovation so that others, like you, who are new will have an even better hobby to come to.

People like Fender have spent hours upon hours teaching, being patient with, and even outright dealing with, new people such as yourself. People such as him have given much to the hobby and if they express their opinions and those opinions are not listened to? I believe they have EARNED the right to be a little testy. Most of the time no one is blatantly hostile, rude or otherwise hurtful. People who join this hobby need to learn what being Critcal means. We are a detail oriented hobby, if you want a quality product you have to be. If you want butterflies and rainbows, go elsewhere....

People who have joined the forum for a week, miss the years of relationships that are built while showing your worth in this hobby... people have been "burned" too many times by new people who take advantage of helpful people and do nothing for themselves. So show a little respect.

[RevengeoftheSeth]

Back on track here...

Copper naturally tarnishes over time. There is a possibility that the combination of heat and weathering caused it to 'appear' that there is corrosion. High humidity will accelerate the problem.

That is why when you see sterling silverware tarnish, its not because of the silver. It's because of the 7.5% copper content.

Quote from Jay...

Aluminum and cast iron don't mix either, yet auto manufacturers have been using aluminum cylinder heads on cast iron engine blocks for decades....the reason they can do it? The head gaskets separate the two metals enough that the corrosion never happens. It's the same with the thermal tape and your led's aluminum base plate.

QFT, not to mention the layer of oil between the two. Tim sells thermal paste and the stars specially made for the LED stars at a very reasonable price.

Quote from Arkhan...

so if I'm leading you on a wild goose chase, I hope they'll step in and provide some gentle correction.

I misread that the first time skimming over it...

[Ronan]

What you need to realize is that this is a Do It Yourself forum. This is a forum to collect and distribute information for those who want to learn "how to" do things in this hobby. Simply by the nature of what this forum is, people MUST be willing to learn, and by that i mean look for and assimilate information. Some people here take that one step further and spend their time and money to fund innovation so that others, like you, who are new will have an even better hobby to come to.

People like Fender have spent hours upon hours teaching, being patient with, and even outright dealing with, new people such as yourself. People such as him have given much to the hobby and if they express their opinions and those opinions are not listened to? I believe they have EARNED the right to be a little testy. Most of the time no one is blatantly hostile, rude or otherwise hurtful. People who join this hobby need to learn what being Critcal means. We are a detail oriented hobby, if you want a quality product you have to be. If you want butterflies and rainbows, go elsewhere....

People who have joined the forum for a week, miss the years of relationships that are built while showing your worth in this hobby... people have been "burned" too many times by new people who take advantage of helpful people and do nothing for themselves. So show a little respect.

Thank you for the explication post, it's most appreciated :)

I know what it means to teach, i'm a Media Designer/Photographer by trade, and i spent just as much time teaching to curious people (usually for free... lol) and i understand how repetitive questions get ANNOYING!

Most of us have been there in our professional career, but that doesn't excuse anyone to blow off some steam or what ever the expression is (English is my second language).

About respect. Respect is earned, and I'm sure he earned his respect a long time ago (i believe i earned mine when i single handily mounted a company at the age of 18 and juggled university with it, or when i went to Afghanistan for humanitarian aids, but you wouldn't know about that, and i wouldn't know about FB). But thats not the issue at hand, to me, someone that just arrives on the forums (i'm not a big forum guy, i have always preferred face to face), and i see someone having short temper (or what ever you want to call it) to someone else seeking help is quite simply wrong/rude and just didn't sit right with me (maybe the 10 hours of driving adds up to it? Or getting a ticket for making a left turn i have been making for 4 years but suddenly you and the 6 other cars can't!!! lol:p).

So to summon everything up, i log in, see a lot of people helping, and then i see some individuals being short with newbies and i found that... strange/disturbing (since it did not flow with the feel/attitude of this forum).

Again, thanks for the answer Shadar, much appreciated mate and like RevengeoftheSeth commented, back to the topic!:cool:

[Skottsaber]

*head falls on keyboard*
not again...

[polarcupz]

*head falls on keyboard*
not again...

Hahaha.

I did find the problem. I tested the heatsink, and the power was flowing right through. There was actual corrosion due to the electricity between the copper heatsink and the aluminum Lux V. The lux V has corrosion all over the back side (the side touching the copper) The metals were not the problem in and of themselves. Fender's sound advice was well taken, and no offense was meant/ and or taken.

My problem and questions have been solved thanks to Arkhan, FenderBender, and others who pointed to the same conclusions.

Thank you!

[Ronan]

Hahaha.

I did find the problem. I tested the heatsink, and the power was flowing right through. There was actual corrosion due to the electricity between the copper heatsink and the aluminum Lux V. The lux V has corrosion all over the back side (the side touching the copper) The metals were not the problem in and of themselves. Fender's sound advice was well taken, and no offense was meant/ and or taken.

My problem and questions have been solved thanks to Arkhan, FenderBender, and others who pointed to the same conclusions.

Thank you!

Glad everything worked out! Theirs nothing more frustrating than a gremlin in a lightsaber!

[psab keel]

One thing that I have been doing as well for my builds has been to polish the back of the LED base (where the heat is transfered to the the heatsink) and the surface of the heatsink itself where the LED is mounted. In many cases I can't get to a build right away and there will be a patina on the metals. This way, if I remove that patina with polishing compound (and some careful dremel work) this will allow both surfaces to conduct heat better through the back of the LED.

I forget which saber builder I saw do that on the threads here as it was some time ago that I saw it, but it seemed to work rather nice. Also, making sure that you are only stripping away just enough of your wire to solder to the terminal on the LED is important. Too often it's a simple error such as this that can cause current to flow through other parts of the saber that shouldn't be conducting ANY electricity.

Hopefully this may help some.

Psab

[Crystal Chambers]

I think I did this once when wiring a saber as a stunt before the sound went in and it was over heating around the blade holder so I assume this is why. I think my leads were bare just a little too much and touching the edge of the star.

[Arkhan]

very glad to hear that you found your problem. I know I learned something along the way, and I'll store that lil tidbit away for future troubleshooting endeavors.