Couple materials questions (aluminum and stainless steel) - and a battery connection question

[subver]

Hey guys, You might start seeing more of me around here. Been vaping for a little over a month now and loving it. Very interested in DIY and modding projects, I'm a craftsman and tinkerer at heart. I've been reading up on a lot of stuff and decided to get a metal lathe and some other tools for the trade. I just had a couple little questions:

1) Aluminum. Does it have to be anodized before touching liquid? Is there "safer" aluminum that can be used, or does anodizing really take care of that with any aluminum?

2) Stainless Steel - I see that "303" is good for machining, but is it good enough for contact with liquid? I know it's very hard to machine already, but should I be trying to go for 304 SS? I'm almost positive 303 will be good, but I just want to make sure.

Anyway, I've got a couple ideas for some rebuildable tank atties I want to make for myself, as well as other "experimental" ideas I'd love to test. I will probably start out with aluminum because of it's ease to work with, but eventually would love to work on stainless steel.

And for the other question.. I've been looking into custom atties and whatnot and one thing that I'm a little foggy on is, at least in regards to the scubagenv3 mod, positive and negative connection. So the positive wire connects to the middle tube in a 510 connection and the negative would be to the outer rim of the battery connector. On the scubagen directions, the positive connects to the middle tube, but the negative just connects to the mod's metal, all the way at the top. I understand that this metal is connected to the negative battery, but it doesn't negatively affect the current in anyway, having to travel through all that metal, instead of running another wire directly to the battery connection?

I'm no electrician, so this could really just be a stupid question, but something that's been bugging me. Running through this much metal, would that drain the battery any more than it would if there was less material to send the current through?

Thanks so much guys! I look forward to posting more here

 

[bstedh]

I can answer the negative terminal question but will leave the metals question to others.

The more metal mass the electricity has to travel over a given distance the better. Think of it in terms of a garden hose. The bigger the inner diameter the less restriction to flow. The positive wire while sufficient for the current we are applying has more resistance than the body of the mod making it the poorer connection. Resistance = wasted energy.

On the flip side of that SS is not the greatest conductor but for the short distance we are talking about here its resistance is negligible.

 

[subver]

Oh wow, great analogy, thanks. So, going for a thicker wire on the positive connection would not be detrimental, and may even be better? If I were to make something out of SS, would it be "worth it" to also weld in a negative connection wire, or is running through the entire metal piece satisfactory?
Thanks!

 

[bstedh]

I wouldn't bother trying to rig up a secondary ground just use the body. Yea the thinner the wire the less current it can handle. Always use the heaviest gauge wire you can work with in your mods.

 

[subver]

Thanks so much, that helps tremendously.

Bonus question for anyone who knows: what is the diameter of the metal rod in the CE2's, for example. I found a source for 510 battery connections and would like to install that inner positive connection rod/tube. Also, what would be the best metal for this connection? Since it's not touching liquid, brass should be good, yeah?

 

[bstedh]

I assume you are building an SGV3. I am not sure about the diameter of the tube as I don't use it anymore but the tubes are made of plated brass in most cases. Basically anything that will take solder would work.

The tube is only needed on an SGV3 if you are looking to pull air from the bottom, I have found it way more efficient to pull the air from the side of the vapor chamber instead. I just drill a small hole in the side of the upper tube and insert a small roll pin from the local hardware store to direct the flow onto the coil.

 

[subver]

Ah ok, I think I just assumed that's how most people built their connections. I think I'm going to base things off the SGV3 at first but I've got a couple ideas in mind I'd like to play with.
Thanks for the tips!

 

[subver]

Still looking for answers on the Aluminum front - does it have to be anodized? Is there a difference in using the Aluminum body as the negative connection if it's anodized or not?

 

[nicotime]

Never tried anodized aluminum as a tank...but its used on cookware so who knows..without anodizing...no way. As far as the electrical part..if you have any anodized parts that electric has to flow thru like two threaded parts...it would need to be ground off to make the circuit. Anodizing is a hard surface oxide a few thousandths deep that is non conductive.

 

[subver]

Ah yeah I just found that out, too (probably should've just googled this stuff). Well, I don't really want to set up an anodizing chamber if I'm just going to be practicing with it anyway.. so maybe I will just practice with aluminum and not use the pieces, then move on to stainless steel (304 probably). I'm kind of scared to even try any other metals like brass due to the reactions with e-liquid.
Although, if I did use anodized aluminum, I could always just anodize the part that touches liquid (or rather, remove the anodization from everything else), that doesn't need to carry a current anyway.

Anyway, are there any other safe metals to use that are easier to machine than stainless steel? I should probably just get really good tools right off the bat meant for stainless steel anyway.

Thanks!

edit: Was just thinking, I'm pretty sure you can work Delrin on a lathe, maybe I should do experimental pieces with this first - that might actually work pretty well.. easy to cut, can probably make the pieces much faster, too.

The only thing is I'll have to wire up the negative as well, but that's not a big deal. I'm excited now. Does anyone see any problems with make a full piece out of Delrin? Delrin and Polycarbonate tubing.

 

[bstedh]

I believe some of the first SGV3 prototypes where made out of Derlin. I was looking at having some made just because they would be a lot lighter but the cost of having them machined was just as expensive as SS so I just stuck with SS to avoid them wearing out over time.

If you do get some successfully made out of derlin I would trade you a SS one. =]

 

[subver]

Awesome, I'll keep you updated for sure! I've got this idea for something similar, but with the tank on top and a vertical wick (so it will wick better with the help of gravity).. definitely going to try and make that as well, just hoping it won't leak! I will make a regular scubagenv3 in delrin as well, so I will keep you updated