Backyard Aquaponics
http://byap.backyardmagazines.com/forum/

Questionable construction materials and/or leaching
http://byap.backyardmagazines.com/forum/viewtopic.php?f=8&t=156		 Page 1 of 9
Author:  steve [ Jun 20th, '06, 18:26 ]
Post subject:  Questionable construction materials and/or leaching
Here we are boys and girls, go nutz, and please remember that everyone is entitled to a point of view :)
Author:  veggie boy [ Jun 20th, '06, 18:37 ]
Post subject:  Re: Questionable construction materials and/or leaching
Does anybody know what PPVC is - as opposed to just PVC.
Author:  monya [ Jun 20th, '06, 19:17 ]
Post subject: 
is one of them uv treated? or masybe that is UPVC. Asked at the plumbing shop about leeching and they reckon neither would
Author:  aquamad [ Jun 20th, '06, 19:27 ]
Post subject: 
:book: This is what I found on the web about pPVC :book:
Plasticised Polyvinyl Chloride - Plasticised PVC – PPVC >300% Elongation.
Polymer Type
Thermoplastic

Advantages
Very soft and flexible, high elongation to break and low melt viscosity compared with PVC with lower levels of plasticisation.

Disadvantages
Poor flammability characteristics, very low tensile strength and modulus compared with PVC with lower levels of plasticisation.

Applications
Cable sheathing, gaskets, terminal shrouds, visors, automotive lamp holders, grommets, handgrips, shoe heels, electric plug covers, Wellington boots, gloves

No mention of pets, aquatics or food...
Author:  veggie boy [ Jun 20th, '06, 19:47 ]
Post subject:  Re: Questionable construction materials and/or leaching
Thanks dude.
Author:  frosty [ Jun 21st, '06, 08:08 ]
Post subject: 
aquamad wrote:
:book: This is what I found on the web about pPVC :book:
Plasticised Polyvinyl Chloride - Plasticised PVC – PPVC >300% Elongation.
Polymer Type
Thermoplastic

Advantages
Very soft and flexible, high elongation to break and low melt viscosity compared with PVC with lower levels of plasticisation.



the plasticiser would be pthylate ( do a google search although my spelling may be off a bit )

it does leech and it is a problem ......... we are all contaminated with it already and the effects are not really known

also steve how did your research on silastic go ?

frosty
Author:  steve [ Jun 21st, '06, 14:33 ]
Post subject:  Re: Questionable construction materials and/or leaching
Frosty,

Sorry i haven't had a chance to get back to you!

Could find no evil dirt on silastic. All negatives were for the liquid silicone used in implants. It migrated to vital organs and interfered with their function, but this was because it was a liquid mass inside the body. Nothing on leaching.

I would have expected to find some documents to say its safe and some to give us the dirt on it, but no.

For all of you who are about to search on phylates, expect to find the standard "no ill effects" doucments, and also the ones that give you a host of issues with it. I'd tend to go the consiracy theorist way and believe the latter documents.

Why? Because i don't have the "if its bad for us they wouldn't give it to us" mentality. If that were so, we wouldn't be using half a dozen food colouring that are BANNED my most other countries, forms of nutra-Sweet that had causal links to cancer since the late seventies nad that are no longer used is many countries. I could go on for hours (and am often known to do so :))

Point is you will find two sides to each story, it depends on which one you want to believe. The way i filter things is: If there is billions of dollars tied up in it, you have been told its comepletely safe for years yet you find concerning health info from "crackpot" sites........... then i'd belive it........remember when cigarettes weren't addictive and didn't casue cancer? The longer a lie is perpetuated the longer for the truth (if ever) to be admitted. some one will stab you for $20 yet we believe that no-one would lie to keep a 100 billion dollar per year gravy train on the tracks?

I'm sure that deep down we know that we are lied to about many things, we are just too busy in our day to day routine for or brain to cope with it, so we subconciously ignore it

Anyway the phylates are my only concern with Polyethelyne (P.E.T) (PolyEthelyne-Tetraphylate )

Frosty if i'm not mistaken one of the possible effects is that it mimics estrogen (or one of the hormones). Could be wrong, has been a long time :)

U know what makes me laugh? we believe the "every cigarette is doing you damage" campaign, but then we accept "safe" limits for toxic and carcinogenic chemicals "becasue they would tell us"

Sorry about the rant guys :)
Author:  steve [ Jun 21st, '06, 14:58 ]
Post subject:  Re: Questionable construction materials and/or leaching
EPDM may be the go

it is a ruber that is manufactured into pond linings. It is considers top of the line, and all sites i find says it does not leach.

It's not cheap, but is exteremely tear and puncture resistant and safe! (Who wants to empty a 2000 litre pond when a yabby pokes a hole in it?)

This was on one of the sites:
Quote:
WARNING! - Many people think that rubber roofing material is the same as pond liner. Yes, rubber roofing is made from EPDM materials but it is not the same! The EPDM materials used in roofing contains toxins that leach out and can be deadly to fish and plants. EPDM pond liners used materials that are refined and have all harmful compounds removed. Your fish will thank you!


EPDM also has a roush surface which has been show to promote colonisation of its surface by benefical bacteria (every little bit helps :))

Check this site out. good info at bottom of page and they only charge $9 shipping, regardless of weight (and liner can get heavy!) They also say its safe for drinking water.

http://www.pond-equipment.creativefount ... _liner.htm

steve
Author:  steve [ Jun 21st, '06, 21:16 ]
Post subject: 
Back in here again :)

VB, so i take it you're not going to be using PVC?

Damn, now i'm falling into the trap of convincing myself that "if it was that bad they wouldn't use it". I know better that that.

Was just going to mention that all the pics you see of aquaculture setups have PVC pipes. How do they do that? I mean i'm fairly sure PVC is not food grade material

Curious
Author:  aquamad [ Jun 21st, '06, 21:20 ]
Post subject: 
Quote:
Was just going to mention that all the pics you see of aquaculture setups have PVC pipes. How do they do that? I mean i'm fairly sure PVC is not food grade material

this concerns me too... I am currently involved in trying to get a grant to set up a system at school from the healthy school communities grants initiative and if the PVC is not 'safe' they might know that and reject our application...
Author:  steve [ Jun 21st, '06, 21:30 ]
Post subject: 
AM don't worry about "them" most people still think what they are told to think. If its used then commercial aquaculture then you'll have no trouble convincing the communities that its all ok. The "it must be ok" syndrome i call it. (oops, hope they're not reading this :))

It's your own mind that will be hard to satisfy.

Sorry EB, don't mean to be disrespecting PVC :oops:
Author:  aquamad [ Jun 21st, '06, 21:32 ]
Post subject: 
but what could I use instead of pVC then???
Author:  Murray [ Jun 21st, '06, 21:37 ]
Post subject: 
Ther is not really anything else Aquamad, not in practical terms anyway. There are possibly millions of homes with PVC pipe fittings in them being used to carry drinking water etc. The ultimate would be stainless steel, but you would need to sell your house to set au a system
Murray
www.boatshop.com.au
Author:  steve [ Jun 21st, '06, 21:38 ]
Post subject: 
Murray,

not being smart, but where are the pvc fitting in the houses except for carrying wast water to the drains?
Author:  aquamad [ Jun 21st, '06, 21:42 ]
Post subject: 
carrying poop :pottytrain4: , that is okay... carrying drinking water...
EEEK :shock:
Page 1 of 9 All times are UTC + 8 hours
Powered by phpBB® Forum Software © phpBB Group
https://www.phpbb.com/