The problem with a galvanized tank will not be during the use, but rather during the construction. Your likely not going to get a quench tank (with oil in it) hot enough to burn off any galvanizing....however, assembling the tank is going to require welding (MIG/TIG/Stick) and that will indeed create hazards.

My recommendation, if at all possible, is to just stay away from using galvanized material. Another aspect that many do not think about is the thickness of material used for a quench tank...our instinct is often to use something "heavy duty". That is fine, but what must be considered is that adding the extra mass that comes from using heavy gauge materials will also increase the time and efficiency of pre-heating the oil. It's actually a double edge sword in that it will take longer to pre-heat the oil, and if you happen to be quenching a few larger blades, the oil will require much longer to cool down, all due to the additional mass.

There is also the fact of is your shop heated? For example, a 3-4 gallon quench tank, made from 1/4" material in an unheated shop, with an outside temp of below freezing may take a LONG time to get the oil pre-heated to a stable temp.

My solution was to build a thermostatically controlled quench tank. My quench tank was built with 3/16" thick material, has two 110V hot water heat elements, connected to a PID controller. I flip a toggle switch, the oil is pre-heated to 120F. The PID controller will ensure the temp is maintained +/-12 degrees....at least until a quench 2-3 larger blades, then I have to wait for the oil to cool before quenching any more blades. Finally, the amount of oil within the tank is an important consideration. I always recommend building a tank that will hold at least 2 gallons of your chosen quenchant.....mine holds 3 1/2 gallons.

Hello Ed;

Thanks for your reply to my post.

I am very much aware of the hazards of welding galvanized material,it is nasty. I am one of these guys that likes to dig around in the scrap pile and make use of what I find.

I will look for something different.

My main concern was, would the galvanized material harm the oil. The spec. sheet on the Duratherm G says, " The quenching system and particularly heating elements and coolers should not consist of copper or copper alloys. These materials act as catalysts, accelerating the aging of mineral oils. Use steel, ferrous castings, stainless steel, nickel plated or tin plated materials instead".

The spec. sheet on the Park #50 says all equipment may be constructed of mild steel.

Thanks Again! ED