DIY water butt

[Forage420]

I recently bought a rainwater kit for my greenhouse and I wanted to connect it up to a container I have salvaged from another plot I will soon be giving up.

One container is a metal dustbin and the other a metal drum looking thing. Both are in reasonable condition.
Rather than buy a rainwater butt I was thinking about lining the inside of these metal containers and using them to store water.

I've a few concerns :
1) the leeching of the plastic lining into the water
2) the constant freeze thawing affecting the integrity of the membrane
3) not having any design ideas that will allow me to fit a tap at the bottom of the drum without affecting the integrity of the membrane. I would be limited to top filling using a watering can only.
4) the build up of sediment in the bottom of the tank and build up of pathogens.
5) a suitable means of enclosing the top of the tank. The dustbin has its own lid which is handy, but the larger drum does not.

Another option would be to wait until I see a suitable water butt on gumtree or freegle and buy it.

[veggiechicken]

How would you line a drum with membrane and make it watertight?

[Baldy]

I would think that you'll have almost impossible issues lining a metal barrel if it isn't already water tight.
Use then as compost bins possibly
Deffo go for the gumtree / freegle option of something actually designed for what you want - if you can

[Chestnut]

I’m sure I saw something on tv that said micro plastics are everywhere, even the air we breathe - so we cannot avoid them completely. That said, I would look for uv stabilised plastic for anything that’s kept outside.
If you don’t want to disrupt the integrity of the membrane, how about a hand operated pump to get water out via the top? Or, if you have another butt, link the two with some tubing to act as a siphon.
Dad did this with an old hula hoop; the open ends of the tubing sat at the bottom of the butts, but the central bit of the tubing ran over the top of the barrels. This was great because no danger of leakage (unlike if you make holes lower down the butts), but water levels in both barrels were the same so you could always fill your can from the one that was easier to get to!

I should also add, I have tried but never succeeded at repairing leaky butts....

[veggiechicken]

I store water in a metal drum and dunk a watering can into it. The thought of sediment, pathogens, leachates or anything else has never crossed my mind - and won't.

[ameno]

My water butt is open-topped and I never clean it. It doesn't have that much sediment at the bottom (maybe 1/4 inch), and I've never been concerned about pathogens, contamination, etc. It never seems to do the plants any harm, nor does it do us any harm when we eat them.

As for the plastic lining, as a general rule chemicals do not leach from plastic into water. It's oils they leach into, as many are oil-soluble (which is why you need special plastics for storing oils and oily products in).

[nickdub]

I've used old metal containers as water butts for approx the last 40 years, indeed I still use mostly metal watering cans. Mostly if they are galvanized and don't leak I just use them as is. If they are iron but not galvanised with no leaks I use hot bitumen painted on the inside. If they leak I first mix some cement (two parts sand) and put that in over the hole very wet (obviously the hole needs to be the lowest point so you may need to alter how they butt stands), then let that dry for a week. Then I paint hot bitumen over all the inside cement included. If it still leaks a bit after that, I drain the butt let it dry thoroughly, then pour in some liquid bitumen mixed with meths.

PS a lot of people wouldn't want to use bitumen in sealing a water butt - that's up to them - I'd just remark that bitumen was a common product for use on the insides of drinking water containers for quite sometime, and that other materials like plastic also have their downsides. If you want to try it but have worries - set it up give the bitumen chance to dry properly - then fill with rain water a few times and empty out on to a spare bit of ground to flush the container out.