Backyard Aquaponics
A place to discuss aquaponics

*frack* knows - what you thinking of. Is tin made up of a number of other metals, what are they?

http://www.lenntech.com/Periodic-chart- ... /Sn-en.htm

tin toxicity link above. organo tin compounds very toxic (pesticides etc) elemental tin NOT, use in food cans.

hows this for a brainstorm. back when i used to make my own circuit boards there was a aqua coloured solution that would tin plate copper in minutes.

get a roll of copper, put it in a shallow container and pour in this solution. you will have a tin plated copper heat exchanger.

whadda ya think?

I'm thinking what is this aqua shit and how poisonous is it. I'm also thinking how much of it would it take to coat 50 metres of tube and how much would that cost.

not sure what it it, i will look it up for you, but it will work on a basic ---ah shit cant remember the work for the reaction--- it will swap the copper into solution for the tin, hence coating it, you can then wash the coil down to remove any residues, coating will be pure tin.

if you get a 18m roll (thats what they come in) its very flat and only the diameter of the pipe high, a shallow tray won't use a big amount of solution, gimme a sec..................

this is the only one i can find now....................

http://www.computronics.com.au/kinsten/chemicals/

you guys are weird

Yes, tin is bad by new standards, but remember that tin cans were the standard of food storage for a very long time .

Even the scrap price of copper is out of site , but maybe the best choice for use in the tank.
The exchanger in the tank has liquid to liquid exchange and the water is circulating past the exchanger. This gives good exchange. Here, a 10 foot length of 1/2 inch copper is about $13US. Four of those should transfer a lot of heat. My setup is 20 feet of 3/4 inch because I had that in the barn. That holds the antifreeze in the system only three degrees above tank temp when the pump is running. That is excellant heat transfer. My solar exchanger is small, so 40 feet would be better for a bigger solar exchanger. Use 50 meters of black poly and no worries about contamination. Sounds good to me.

Steve, I really like your tin coat idea! I used that tin plate stuff on circuit boards too. You are right, once you rinse off the tin, you just have tin. I see no down side. Way better than paint. Where were you before I did mine? Next time, I will do it right the Steve way !

I like the idea too but can't imagine being able to bath the pipe properly. It would be impossible to do it after bending it to the shape of the exchanger and if done before - I'd probably lose a lot of the coating while bending.

tin is just tin, chemical symbol Sn.

dunn about it cracking VB, is probably worth a go on a shor piece, then ben it to the tightest angle you're going to use.

BTW, why not just leave it in the shape of the roll?

I'll probably use about 50 metres - back and forward from one side of the sump to the other.

why not say a 20m coil laying flat on the bottom? you'll get natural convection currents upwards? I dare say you'd get all the heat tx you would want from the 20m (sorry i don't have the kg/kg to back it up, just the vibe )

continuing on from Steve's query about leaving it on the roll... how big are the rolls? What size is the sump again? are you keeping anything else in it?
If you joined a number of rolls of pipe together, keeping them in the roll, you might be able to arrange them in the tank like a bunch of slinkies (the kids toy) (or almost like little rainbows )

i did think of that, but thiguht also that VB might make fun of me

seriously, go with the 20m to start

I'm probably unlikely to go with copper at all due to the issues with coating it. Am looking into SS.