Aluminum or Brass?

[rc10gtisthebest]

I am about to complete the next step of my boat building process.

And I needed to know If I should stick with the ordinary Brass Tube setup for the Flexshaft Housing? or Could I go with aluminum?

I think aluminum would be better because it would last longer then the brass would?

Am I wrong to consider the switch?

Thanks,
Todd

[rc10gtisthebest]

I can also get my hnds on Stainless Steel tubing and Copper tubing. Any suggestions?


Also can someone off hand tell me what size fuel tank tubing is (The Brass Tubing)

Thanks again,
Todd

[BoatDoc]

i forget which size tubing is usually used. but brass or aluminum is fine. they are both flexible enough. aluminum is just slightly lighter, but not enough to ever really make a difference. it's all a matter of preference.

[Watercadet]

Go with the brass over the AL. There must be a reason that brass is what everyone uses... I would think that AL would kink too easy.
Adam

[Doubledog]

Think about it this way... If the flex shaft breaks what would you rather have then? Consider the ragged end of a cable whipping around inside.

Though it depends on your application also. (what is it exactly?) if its nitro or gas then go with brass. Someone wrote about using teflon then it is fine to use aluminum. Might be, but then again, if that cable breaks inside, the teflon is going to possibly get ripped up and then scar the aluminum even worse.

Take a drive shaft down to the local hardware store, size it up and buy a few sections. Speaking of which, I've got a family member doing the same thing for me and dropping it in the mail. For my application, I requested 1/4" & 5/16" @ 6ft each. Got to have enough for later.

[BurnZ]

Brass is soft and "will not" scratch other metals. We use brass when working in our plastic dies. Another reason I can think of is brass won't spark either. This is why it is used for shell casing for rifles and hand guns.

[BoatDoc]

if you don't use a teflon liner, then brass is the best choice. brass is self-lubricating (i'm not going to explain it...has to do with zinc). IMHO, that is the only difference between brass and Al as far as using them for stuffing tubes. as for kinking the tube, as long as you make the bends with the flex shaft inside of the tube, it won't kink. both will kink if you're not careful. hey DD...hate to contradict you but with the possibility of breaking a shaft, i don't think that brass would hold up any better than Al. they are both soft metals, and the flex shaft is made from steel threads...steel is harder and will therefore win everytime. don't use stainless for a tube, it's heavy and too stiff. and copper is basically brass minus the zinc. not trying to sound like a know-it-all but metal working is an old hobby of mine.

[Doubledog]

No, no, no. Not condradicting in no way brother. :)

I'm not talking about breaking, but abrasion resistance. Which one is tougher? I'm guessing the brass. Never sat down and scrubbed one or the other to see.

Now throw in the possiblility of getting your hands on some steel tube, then there's no comparison.

<sigh>
How to explain? We use what works for us & what we see a lot of others using too.

No disagreement, just discussion. Share a little more if you don't mind.

[Rosati]

Unless your aluminum is anodized, it will react to the water and evetually pit. Brass is the best material around water.

[mjmsprt40]

I wonder about fatigue resistance betweeen brass and aluminum. There's no getting around the fact that a revolving flex cable sets up some vibrations in the shaft log, which the metal has to absorb in some way. Along similar lines, we have to have some way to keep the shaft log secured to the hull and it occurs to me that aluminum just might have a problem here.

The corrosion problem isn't so severe in our models, especially if you're taking good care of your equipment. In full size, you bet corrosion is a problem! Aluminum is a "noble" metal, which means it will corrode faster than the steel flex-cable we use. In full-size practice, they use Zinc anodes to overcome this galvanic corrosion. Zinc will corrode faster than aluminum or steel, thereby saving both metals at the expense of the zinc.

[BoatDoc]

the grade of brass is what is important. it depends on the level of zinc used to make it. for those that don't know much about metals, brass is a copper/zinc alloy. the less zinc, the more prone to corrosion it is. zinc is also what makes brass "self lubricating" as i stated before. what i think is that (and the point i'm really trying to make) is that when it comes down to it, it's just a matter of one's preference. i have one boat that i run with Al for a tube, and one of the one's i'm building is brass. in the future, i'll probably lean towards Al...just because i like it. one last thing...about corrosion on Al, just keep it clean. my electric rigger has all Al hardware and stuffing tube. no corrosion yet.

[Watercadet]

Wow I am dumb! more like it was late at night... ya... that's the ticket. For one of those reasons I thought this was for fuel line. Ya brass for all the reasons above :P The self lubricating is big. AL will wear faster, and the brass WILL hold up better than AL. Be sure to anneal the tube before you bend, and have the shaft inside when you bend as mentioned above.
Adam

[BMAD01]

Be sure to anneal the tube before you bend, and have the shaft inside when you bend as mentioned above.(QUOTE)

I do'nt even do that! I've got a SpeedMaster strut. The "5/16" BRASS TUBING", slides into it. Then I have the flex inside the tubing, and start bending, VERE, VERY, SLOWLY! It will take longer than you expect to get the stuffing tube bent where ya want it, but thats a GOOD THING! Ya do'nt wanna rush this process. And you can "rebend", if necessary. ME? I would'nt even consider using aluminum for a stuffing tube! Why? Because it's too soft! Brass is a natural bearing surface, and will last forever. And that's 2 answers for ya! And another thing, forget about a "teflon liner"! Ya do'nt need one either. It's just another thing to maintain, and when they go bad, yer in for a whole new world of trouble! :mad: Good luck, Brian :)


Sorry, Been watchin this post for a couple days now. Just had ta throw in my $.02

[rc10gtisthebest]

Well I bought both the Alum and Brass. Looking at what ya'll have had to say, I will go with the brass. I'll save the aluminum for another day and another project. I don't plan to use a teflon liner because I am on a pretty tight budget.

Thanks Again!

[Watercadet]

Big on annealing. Get it glowing then quench it in water. It will bend like BUDDA (butter read like the Mafia). Get it to the shape you want, then re-heat and let cool slowly. It will be harder than bofore you got it! I like to bend themon a flat surface to prevent the tube bending latteraly as well.
Adam