Aluminum vs Saltwater (how corrosive?)

[McMillin5]

Im in the process of ordering a new Evergrow aka Reefbreeders IT2080 LED light set up and it hangs from cables and I dont really want to or like the look of cables hanging from the ceiling, so my question is that I have some Aluminum material left over from my Experimental aircraft build and i have a really good idea on how too build a retro kit to mount the light from a piece of aluminum square tubing but how bad will the aluminum corrode over time from the salt?.. iv herd that their is a treatment for can apply to prevent it but im asking if its necessary or not?

[surgy]

from my understanding all of the better quality, pre-manufactured, led light ballast/lamps have exposed aluminum heatsink. been reading a LOT all of my free time for 3 or four weeks and havnt ever heard of them corroding to the point of being mentioned. only thing i would worry about (and im as unexperienced as they come, soo take with a grain of salt) is the watter evaporating corroding and then dripping back in and slowwing changing the tank parameters in some way

[McMillin5]

my current Marinland LED light sits about 3-4" (guesstimate) and it doesnt have any condensation at all but yes im not sure about just the bare aluminum and I could also powder coat the frame of my design clear (this thought just hit me lol) input still wanted please

[Rognin]

Aluminum corrodes quickly when immersed in an electrolytic solution (ie: water). The purer the water the less the corrosion (in which case salt water is highly electolytic). But you need an anode and a diode metal to create corrosion, if only one type of metal is present then corrosion comes along at a very slow place. To know what corrodes quickly or not, google noble metals corrosion.

I learnt all this will liquid cooled computers. Never mix alu with any metals, it just melts away.

As for it being out of the water, you may see corrosion spots (not big chunks) if you don't wipe it down on a regular bases and have a cold house (condensation). Other than that it should stay pretty clean except for salt creep.

:2cents:

[McMillin5]

Rognin: thank you for that info.. what do you think about clear powdercoat? my dad used to have a powder coat shop and I can get it done for cheap or free depends if i catch him at the right time when he's spraying clear lol

[Rognin]

I like powder coat finishes, but I don't know how it reacts to salt & humidity. I'll have to look it up tonight...

My guess is it should be alright since it's not chemically sprayed on, but cooked on. There's also the fact that a lot of the higher end lights are either powder coated or brushed. I'd safely bet you can powder coat it without any worries. Then again I'm no engineer... =P

[Breadman03]

Definitely look into powder coating.

http://powder-pro.net/marine.htm

http://seattlepowdercoat.com/myths__faqs

[Rognin]

Come to think of it, I wouldn't be worried about the alu framing or cover. I'd be more worried about steel screws/bolts/nuts being used on bare alu with humidity and salt (if they touch it goes faster). So if the unit is powder coated, you may get a longer life time. Including screws/nuts/bolts that aren't alu and contact the alu or alu parts.

But then it's becoming OCD and by the time it rots you'll have long bought something new.

[McMillin5]

Rognin: im going to use alu rivets because i have lots left over and it will look cleaner also to i think im going to build it completely and then drop it off and spray it all clear.. ill post some pics when i get it done it will be alittle while tho the wife is going to buy me the light for a hopefully early birthday present lol

[pool guy]

Hey McMillin, I posted a pic of my frame stand on my thread if you want to take a look. Far from done. I also put the info on where I got the plans for the framework.

[McMillin5]

sorry for the poor drawing but i guess you get the idea with my existing light the green part will be a bracket ill make out of aluminum and the yellow dots will be aluminum rivets and the down post in the back of the tank will run down and ill use two U bolts through the wood on the stand.. Ideas? thoughts?

[Michigan Mike]

I like the idea but I would place the elbow much higher so you can easily raise the fixture up @ least 16" or more so you can move the lights out of the way.

I wouldn't worry about the aluminum if you made it higher.

[mfinn]

I made a hanger for my Radion out of 2" x 3/8" and 1" x 1/8th" aluminum flat bar several months ago and so far I see no problems.
A friend told me about a build where they used some aluminum over a tank and used a silicone spray on it to prevent any corrosion.
I really like the look of the aluminum.
I borrowed the idea from a build here on RC for the hanger.

[mfinn]

I have also considered having it anodized a light blue

[McMillin5]

That was my first idea ^^^ but im going to use square tubing so i can run the power cable inside so you wont see it.. i like the clean open look.. but really appreciate your post mfinn

[Paul B]

I built my LED fixture from aluminum tubing and it hangs on cables over my tank. The aluminum doesn't really corrode but it gets a white powder film that you really can't clean off. I didn't want to paint it because it is also a heat sink but if the LEDs were not mounted right on the aluminum I would have painted it. Mine is behind a wall and is on counterweights so it raised out of the way. Of course you can't see this.

[McMillin5]

dont really care for anodizing plus not really too sure who does it around my area.. my dad owned a powder coat shop and i get stuff dont for free most of the time so ill just have him spray some clear on it

[mfinn]

Ok, I have another one for you.

I made a rack out of 1" square aluminum tube that was powdercoated for 3 Radions over my 240 gallon softy tank.
This was so easy.
http://eztube.com/catalog
The corner connectors made it like putting tinker toys together.

[McMillin5]

mfinn: thanks dude i appreciate it, its only going to cost 50$ shipped to my door going that route, quick and easy too.. the nylon connections do they fit good and tight or did you put a bolt or something to hold it together good?

[mfinn]

They fit sooo tight, make sure your measurements are exactly where you want them cuz, getting it apart is near impossible.
Also, if you go this route, don't forget the endcaps ( I did )
They are on a different page from the regular connectors.

With my rack, it cost about $124 and I had 4' left over.
I checked one popular ( very good) website that made mounts for my Radions and others and the bill would have been over $250 plus shipping.

[McMillin5]

yeah i made sure to get end caps. all i need is a T and one 90 but they say glass filled so im assuming their not hollow? because i want to be able to run my power cable through it so you cant see it.. im a machinist by trade so im sure i can try to machine the fittings but not much room to work with because its only 1"

[mfinn]

They didn't seem hollow.
Before I made my order, I was worried about if they were strong enough, but after getting them I could see they would work pretty nice.

You should be able to drill a hole through it, but probally not big enough for the plug. May have to re-wire it.