Quench tank Flow ?

[SKIVIE]

Today was a very successfull day at the thrift store for my Heat Treating setup: I purchased a Toaster Oven $3, Griddle $2, and a lare pot (aprox 2.5 gal) $1.50. Today im getting everything set up to start HT some blades ive got done. On the Pot for Quenching ive got a pump wich i going to use to keep the oil moving do you suggest I put one of the hoses at the bottom of the pot and one near the top ? wich one where ? obviously the oil at the bottom will warm up faster and stay at a more constant temp I thought I would pull from there and then on the hose coming back to th pot just put it towards the top.....

What do you all think ?....

Shane

[DiamondG Knives]

Shane:
I dont have any experiance on thos topic, but wouldnt the natural convection of heat rising move your quench liquid from the bottom to the top naturaly?

Just wondering if added mechanical motion is actualy needed.

Mike

[Darren Ellis]

Originally posted by DiamondG Knives
Just wondering if added mechanical motion is actualy needed.

Yep, it's a good feature to have, even though most of us don't have it on our quench tanks, we probably should in an effort to eliminate any variables that could prevent the fastest cooling rates possible with our choice of quenchant...if you don't miss the nose of that all important curve, you don't initiate martensite transformation. I'm going to build one as soon as I find a pump that is suitable.



-Darren

[SKIVIE]

Well The tank is done. pump seems to work like a charm. I filled it with water, turned on my griddle to heat the pot im using as a quench tank, figured out what setting got it to around 130 and marked it. just using a little candy thermometer to keep an I on it. the pump and circulation seems to work fine.

I got my hands on 5 gallons of some oil called 100wt machine oil. Im Heat treating 0-1. That should work shouldnt it. I could go buy some veg oil or cannola but since this is free I figured I might as well use it. What do you think ?

Shane

[SKIVIE]

since I posted that last one I actually opened the oil and it seems a little thick, maybe too thick for this.

Would still like to hear your thoughts.

Shane

[AwP]

100 weight is awfully thick, most folks not using vegatable type oils or "official quench oil" use either regular moter oil which is rarely thicker then 15w40, or transmission fluid which is thinner then that (and has good heat transfer properties). I personally use a roughly 50-50 mix of transmission fluid and 5w20 semi-synthetic oil right now.

[AKmik]

Hello guys,

This info is just what I am looking for as well. On the quench tank what would the optimum size tank be for quenching one blade (0-1) at a time be?

I don't have a pump to circulate oil. Right now I have a large coffee can ful of 10w40 motor oil. With the oil at 160degrees. I have done some blades in it and it seems to work good, and the temp isn't jumping too bad once the blade goes in. Am I in need of adjustments here of will this do?

SKIVIE,

Sounds like the 2.5 gal set up with the pump is the way to go. I need to find something like that.

[JGardner]

I recently set up a heated quench tank using the bottom out of an old hot water heater and the pump out of a washing machine. I cut the bottom out of the tank a few inches above the thermostat mount. I replaced the factory element with a little 110v unit. I then dilled three 1/2 holes in the tank, one each 180 degrees from the element at the top and bottom, and one 90 degrees from the element in the middle of the tank. In each hole I soldered in pipe fittings to use a hose connectors. I scavenged a pump and flex shaft from an old washing machine with a burned out motor. I had an old motor sitting around from another project which I used to drive the pump. I welded up a shallow tray from some 1 1/2 or 2 inch angle (I can't remember) then glued a bottom in it. Each side of the edge quench tank has a drilled and fitted nipple, one with a valve. The upper quench tank return line sits directly above the main tank so it gravity feeds back in.

The beautiful part is the pump has two inlets and two outlets, so I am able to have constant recirculation within my main tank. I can then open a valve to the upper edge quench tank and adjust the level of the fluid as needed.

On the downside the tank I used holds about fifteen gallons of oil. If I have to do it over, I would find a smaller tank. Also, I would not solder in the pipe nipples. I had to use heavier tubing than expected so I am afraid any lateral stress on the solder joints will result in 15 gallons of oil on my floor.

With this set up I can heat the entire contents to 120 to 150 degrees (I am still experimenting) in about 30 to 45 minutes.

Justin

[Sweany]

I don't have a pump to circulate oil. Right now I have a large coffee can ful of 10w40 motor oil. With the oil at 160degrees. I have done some blades in it and it seems to work good, and the temp isn't jumping too bad once the blade goes in. Am I in need of adjustments here of will this do?

Tansmission fluid or cheap veggie oil would be better than motor oil. IMO Motor oil has all kinda additives in it, that ain't so very good for you. Tranny oil is mineral oil with ssome heat removing additives. Veggie oil is a good alternative, ans smells better.

Friend of mine used to work for a commercial heat treater, they quenched pallets of wrenches in one batch. They used a a pump.

He suggested using a small motor with an impeller (like a paint mixer) to circulate the oil.


JGardner, I got the same setup, except haven't scrounged the pump yet. I powered the heating elements with 110v they heat up fine. Mine holds 10 gal.

[Jeff Higgins]

McMaster-Carr sells quenching oil. They have two kinds: Fast quench, and a standard quench. The standard oil is a 28-second quench time, and the fast is a 10-second quench time (taking this right out of the catalog copy). They are available in 1, 5, and 30-gallon containers. The 5-gallon container is $36, and they will ship this via UPS ground to your doorstep.

I use both types and they are quite good, and easily accessible. All you need is a phone and a credit card!

http://www.mcmaster.com/