Inexpensive Master Batched Lye Tank?

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Aug 12, 2021
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Wall Township New Jersey
Hello fellow soapers! I’ve been master batching my lye for a few years and love it! I’ve been looking for a storage tank that won’t break the bank and I may have found one, but wanted to get your thoughts on it. It’s actually a beer making boiler, but it’s capacity Is 9 gallons (so really 7.5 or 8) it’s stainless steel and has a clamp down lid. It’s called a Digiboil, and it’s also great for a smaller melting tank should anyone be looking for that! It’s only $179.00 AND free shipping! I know it may be a little overkill in terms of the heating elements as I wouldn’t actually use them, but it’s got the faucet and clamp on lid that’s awesome. And the fact that I already have one that was formerly used as my melting tank until I got my 20 gallon one recently.
SO… all that said, do y’all think it would be ok for lye water storage? I’ve called several distributors and no one scan say yes or no.
My first thought is to check what the elements are made from, plus any fittings. If there is a metal other than stainless steel, it's a no go for lye, I'm afraid.
Yes, I thought of that and looking at it I can't see that there is anything else the liquid would come in contact with; the spigot is even stainless steel. My number 1 worry is if the stainless steel is good enough as not all is created equal.
Thank you for responding! I was hoping someone might be familiar with the unit and be ale to give me a yeah or neigh...
There are usually seals inside the spigot's valve that prevent the valve from leaking. These seals must be impervious to concentrated alkali if you want to store NaOH solution in the tank. If you're buying a general purpose tank, it's very likely the seals won't be suitable for concentrated alkali.

Personally, I'd get a high density polyethylene or polypropylene carboy that is purposely designed for concentrated alkali. Here are some products that might suit your purpose -- Polypropylene (PP, PPCO) Carboys | Thermo Fisher Scientific - US

If you want the tank to have a bottom spigot, keep in mind that there will inevitably be leaks, drips, and spills. A safety measure often used in the chemical industry is to place the tank in an enclosure large enough to contain the full volume of the storage tank if it would happen to fail. That way if a spill happens when filling the tank or a valve leaks from damage or age or someone doesn't close the bottom valve completely, the alkali solution will be fully contained in a safe secondary enclosure.

It is tempting for a smaller container to not do this, but it's still a wise precaution to take. I can't imagine what it would be like to deal with 5-10 gallons of concentrated NaOH leaking all over the floor. I store my 2.5 liter NaOH carboy in a 5 gallon bucket for this reason.