My brainstorm idea to help with polycarbonate tank cracking

[my4jewels]

Okay, I admit that I am obsessed with tanks. I have lots of them. I DIY, and I make lots of juice, lots of flavors, lost of fruity citrus types. As many of you know, I am on a quest for a low priced solution to a great tank system. I have tried many methods of making my own and modding tanks that I own.

My criteria is simple. Easy refilling(no syringes or fill ports), hot switching of cartos, durability against cracking, mostly very inexpensive. I may have had a brainstorm this morning.

I was thinking of the tank tints sold by vaprescence.com for their liquinators, and I was wondering if applying this to a polycarbonate tube would stop cracking. It appears that BDV is coming out with a tank that appears to be stainless over polycarbonate, glued or sealed together somehow. According to a video I just watched, the tube inside is impervious to cracking from juice that are SURE to cause cracking.

Here's my brainstorm: Perhaps we could strengthen our polycarbonate tanks by covering them with clear contact paper. Possible toxicity is not a problem because the contact paper would be on the outside of the tank, never touching the juice.

I'm gonna try it ASAP with a really acidic juice. My schedule does not allow for "tinkering time" right now, but soon...

Whaddya think?

 

[Lyle Devine]

I think that you are getting at a very interesting problem, and many of us trying to figure out how to fix, here is what info I have up till now, and some of the arguements:

Problems (Percieved or Actual)

Plastics (polycarbonate) BPA leaching into e-liquid, unless BPA Free. (I will not argue about if the amount of BPA that is leached is dangerious) personal choice.

Cracking -despite what many think this is not about "bad" e-liquid, but about the varying degrees of material incompatibility, polycarb-plastic degrades/weakens when exposed to various solvents, this creates the clouding or cracking, solvents including substances like e-liquid... I feel fairly safe in saying that all e-liquid is incompatible, just some do the job quiker than others.

Answer:

Glass or Stainless Steel, More Later...

 

[WillyB]

I think polycarbonate is just a poor choice... period.

 

[my4jewels]

I agree with what you have said. I have too many tanks going for glass or stainless steel tanks, I can't justify the cost, at least, right now. What is your opinion about polypropylene?

I think that you are getting at a very interesting problem, and many of us trying to figure out how to fix, here is what info I have up till now, and some of the arguements:

Problems (Percieved or Actual)

Plastics (polycarbonate) BPA leaching into e-liquid, unless BPA Free. (I will not argue about if the amount of BPA that is leached is dangerious) personal choice.

Cracking -despite what many think this is not about "bad" e-liquid, but about the varying degrees of material incompatibility, polycarb-plastic degrades/weakens when exposed to various solvents, this creates the clouding or cracking, solvents including substances like e-liquid... I feel fairly safe in saying that all e-liquid is incompatible, just some do the job quiker than others.

Answer:

Glass or Stainless Steel, More Later...

 

[my4jewels]

***Agreed.

I think polycarbonate is just a poor choice... period.

 

[Lyle Devine]

I have heard of folks cutting down syringe tubes, in the correct diameter and length, with great success. I know that big daddy vapes . com sells SS and pyrex for the lil'mama and big daddy... not sure if it is the same diameter of the liquinator so that I could cut down a big daddy to fit... really getting a length of SS tube in the diameter you need and using a pipe cutter and cut to length would be fairly inexpensive and maybe fun? make sure to finish the edge with a file and steel wool.

 

[Lyle Devine]

I used to work with a medical/scientific glass blower, and wish I still had the contact, because I have not found medical grade glass test tubes in the right diameter that can be cut down. You want Med or Food Grade Glass because in some "Crystal-Ware" it contains lead. Lead = Bad.

 

[WillyB]

I have no idea about the safety or what it is, but these work great.

22mm .35oz Vials with Cap

NotCig claims to be using a tube that supposedly also holds up.

M1A1 Buzz Tank - notcigs.com

Plastic Tanks - notcigs.com

 

[Lyle Devine]

So I checked out the links... and it is great that they found something that works, but their statment that the material is something only they have, I think is really only something they found that works and not willing to share what it is, not something that is made only for them...

 

[my4jewels]

I had followed the M1A1 tank from notcigs when it was being developed, and after that for a while, and there was at least one instance I read where there was a customer who had cracking issues, so there were probably others.

So I checked out the links... and it is great that they found something that works, but their statment that the material is something only they have, I think is really only something they found that works and not willing to share what it is, not something that is made only for them...

 

[VpnDrgn]

According to the chemical reaction specs, polycarbonate should work just fine.

IMO the problem is vendors may be claiming polycarbonate and it is not.
Another factor may be how they cut down the tubes, causing micro stress fractures.
Properly sanding and polishing the cut ends would eliminate this problem,
but that would take more work and materials.

 

[tonyorion]

There are 3 basic problems with polycarbonate:

1) It sucks absolutely for its chemical resistance
2) Being an amorphous (non crystalline) material, it is subject to the "notching" effect. A poor finish at the cut will cause a crack to propagate along the notch.
3) Differential rates of expansion in the different materials (neoprenerine, steel, plastic) when added to the other two issues just make the choice of PC a poor one.

I have seen many product recalls because PC failed. I strongly disagree with the statement that it should work fine because the spec sheet says so. While PC may be OK with pure PG or VG, there is no way to know the impact of the gazillion possilbe combinations of flavorings on PC without going out and testing it. The chemical resistance tables are not that complete. I have a Master's in Chemical Engineering and spent the very first part of my career in materials testing, so I do have a clue as to what I am talking about.

Polypropylene would be a far, far better choice as well as other materials (PET, PTFE, FEP, HDPE). There are tubes available in these materials, although you might have trouble finding a supplier who would be willing to sell you tubing of the right dimensions in small quantities. Glass works as well, although cutting it would be a bit of challenge for most people. A friend dug up a 10" section of glass tubing that was perfect for making tanks, but he has no idea where it came from. My suggestion is to google rigid plastic tubing. Wall thickness may be an issue since these alternatives are not very rigid.