Brass + Juice = :(

[highping]

I just wanted to throw this out there, as I have made (and posted) a few mods using brass feeder tubes....

I have been using bottom feed mods for a few months now and have never seen any issues with the brass breaking down in the juice (until now). Some of my mods have 3ml bottles (which get me through 2-3 days) and some have 6ml bottles (which will last me 4-5 days).
When I was using these mods and changing the juice out every few days, I never had any discoloration of the liquid. And I was watching closely because I want to see if there was any backwash from the atty. The liquid always remained clean and clear to the last drop.

A couple weeks ago I had set aside one of my 18650 mods (with a 6ml bottle) and moved on to testing another mod. Yesterday I went to get it to use for the day and ... ... green liquid .

So I guess brass does not like to soak in liquid for a couple weeks at a time. Even though I never noticed any problems with the juice when I was using it up faster, I have to assume that if there is enough contaimination to see in a couple weeks, that there is probably trace amounts from day 1.

I would have guessed that this would happen with copper, but I thought I was ok with brass. Anyone tried aluminum?

Anyway, if anyone is planning on making a juice feed mod just keep this in mind (and maybe stick with plastic tubing).


This is a pic of the original juice and the same juice after two weeks with the brass....

 

[Mr.Self_Destruct]

oxidization when it hits the air, when you are using it the liquid never lets the air hit it.

 

[Soundwave]

Highping thanks for the update. I just ordered the parts all except for the brass tube which I was going to get today at a local hobby shop... In order for me to proceed with this mod could I still bottom feed with a plastic tube? If so what kind of plastic and where could I get it?

 

[Blaze]

You could use 440 Stainless steel tubing without fear of contamination of the juice, but that might get a bit expensive (although compared to your health, maybe not )

 

[nicotime]

Stainless+steel+tubing In Categories- SmallParts.com

 

[highping]

Highping thanks for the update. I just ordered the parts all except for the brass tube which I was going to get today at a local hobby shop... In order for me to proceed with this mod could I still bottom feed with a plastic tube? If so what kind of plastic and where could I get it?

You should be ok using the brass at the atty connector (the juice will not sit there). I would just cut off the brass a half inch or so into the bottle and slide a plastic tube over it to go to the bottome of the bottle. I think the problem is with the part of the pipe that is always imersed in juice.

You could use 440 Stainless steel tubing without fear of contamination of the juice, but that might get a bit expensive (although compared to your health, maybe not )

Probably not too expensive since you only need 3 inches of 1/16" pipe How much could that be. The problem with stainless and aluminum is that you can't solder to it.

 

[Soundwave]

What inside diameter should I get? I'm going to buy it but its alot of money and don't want to get it wrong. Wouldn't titanium be better than stainless steel?

 

[highping]

What inside diameter should I get? I'm going to buy it but its alot of money and don't want to get it wrong. Wouldn't titanium be better than stainless steel?

That's the hard part. It depends on the atty (510, 901, etc). It's more the O.D. that you want to look at. 1/16" is a good place to start, but it may need to be sanded down a little to get it in.

Your best bet is to take an atty to the hobby store and figure out the best O.D. for your atty. Then take those demensions to your online source. Your hobby store may carry SS and plastic tubing also.

If you are following the method in the $8 JB tutorial, you can get a pipe that is way small because you are running it through the center post of the connector. The atty will seal against the center post. so the tube doesn't need to be a tight fit in the atty.

 

[Soundwave]

High Ping I just got a vendor to send me a sample for my "Project" and if you could give me the ID of the brass tube you currently have I would love you forever and name my next son after your forum name.

 

[roadrash]

You should be ok using the brass at the atty connector (the juice will not sit there). I would just cut off the brass a half inch or so into the bottle and slide a plastic tube over it to go to the bottome of the bottle. I think the problem is with the part of the pipe that is always imersed in juice.

Hi Ping,
Just my 2 ps, but doesn't oxidation happen outside of liquid?

 

[highping]

High Ping I just got a vendor to send me a sample for my "Project" and if you could give me the ID of the brass tube you currently have I would love you forever and name my next son after your forum name.

I wish I could, but the tubing I am using came in a big 'grab bag' of pieces that I got from Hobby Lobby. The bag had about a hundred pieces of round, square, rectangle, brass, copper, alum, etc. for 15 bucks, so I couldn't pass it up.
I meassured (about) 1/16" but that's just eyeballing on a 25' tape with 1/16" markers. I can't say to get 1/16" because I don't have any calipers to give you an accurate dimension . Maybe someone else does?? The best thing to do is get one pipe slightly small and one slightly big, then use them together and eliminate the center connector completely (like the post in the other thread).

 

[nicotime]

The problem with stainless and aluminum is that you can't solder to it.

Sure you can.

 

[highping]

Hi Ping,
Just my 2 ps, but doesn't oxidation happen outside of liquid?

I don't know the chemistry of it, I just know it turned the liquid green. Seems that it could be oxidizing on the metal that is above the liquid line, then 'washing off' into the liquid.

 

[Blaze]

Probably not too expensive since you only need 3 inches of 1/16" pipe How much could that be. The problem with stainless and aluminum is that you can't solder to it.

You could use epoxy putty (or regular epoxy) to hold it in place at the atty connector, and use food grade silicone at the bottle.

Thoughts? Would this hold up under use?

 

[johnnybass]

I am a coppersmith by trade and i work with brass all the time , and just like copper any type of moisture will break it down, I have 2 bottom feed box's myself and i use aluminum tubing, I don't solder it in because you can't. i do however make a stop pin on the top and when i put it together i put a little vasoline on the tube itself then epoxy around it , that way when the epoxy cures it just slides right out.

 

[cypresss]

I am a coppersmith by trade and i work with brass all the time , and just like copper any type of moisture will break it down, I have 2 bottom feed box's myself and i use aluminum tubing, I don't solder it in because you can't. i do however make a stop pin on the top and when i put it together i put a little vasoline on the tube itself then epoxy around it , that way when the epoxy cures it just slides right out.

Aluminum Tubing

What sort of stop pin? Can you elaborate? I bought the parts for some box mods and skipped the brass tubing for all of the reasons mentioned. Instead I went with the aluminum tubes in the link. I was wrestling with the idea of how to keep the tube in place.

Cypresss

 

[Scottbee]

As an aside.. someone mentioned using 440 SST. I would suggest against using virtually any of the 400 series stainless steels. 300 series (303, 304, 316, etc..) would be a better choice.

If you're not sure what series your stainless is, hold a magnet to it. 400 series is magnetically permeable.. where the 300 series is generally not (or to a much, much lesser degree). 400 series can and will "rust".

 

[Blaze]

If you're not sure what series your stainless is, hold a magnet to it. 400 series is magnetically permeable.. where the 300 series is generally not (or to a much, much lesser degree). 400 series can and will "rust".

So the 300 series won't rust? That would be the way to go then. I just always thought the 400 series SS was better since that's what they make surgical instruments from (but they are a "disposable" item, so I guess they don't have to take rust into account LOL )

 

[asdaq]

Highping, doesn't aluminum oxidize too? It seems plastic would be best inside the bottle. With the 3ml bottle I have a 3mm aluminum tube that fits nicely over the inner nipple of the tip as it seemed too small to get my brass tubing through. It hasn't sit long enough to notice a problem though.

 

[Rocketman]

A word of caution about brass:
Brass fittings not intended for potable water supplies may have a small percentage of lead in them (1 to 2%). Tubing extrusion processes end up working lead into the surface of the brass. Chinese brass may have more lead in it , and maybe even cadmium

pH of the juice may accelerate breakdown of the brass.
Plastic is not plastic. Which type of plastic would be the safest? Leaching is now a health concern.
Aluminum oxide is believed to contribute to alzheimers (sp)? but then you probably wouldn't care about it anyway

304 SS would probably be the safest material to use.

HP, good catch.

Rocket