My paint-mixer agitator for quenchant

Patrick, that looks like a neat setup, I'm afraid I don't totally understand the benefits. Could you enlighten me please?
 
Wouldn't the swirling motion of the quenchant be similar to moving the blade side-to-side during the quench? This is typically ill advised. I might be missing something though. Just curious.
 
Agitation is to break up the vapour phase of the quench .To move the blade it should always be edge to spine .Side to side invites warping .The best is a design that shoots oil from below .It's uniform ,breaks up the vapour immediately.
 
As long as the cooling is evenly distributed, the swirl shouldn't matter. In moving a blade side to side, one side is cooled more than the other. As mete said, a stream coming straight up or down from the bottom center works best.

The oil cooler is good for multiple blade quenching. Use a thermostatic switch ( PID works great) to turn the pump on and off as needed to maintain temperature. In the average forge shop, an oil cooler isn't needed.
 
This is Parks 50. I let the agitator and chiller run during my entire quenching session, which is usually 10 to 50 items. "Stirring" wasn't cutting it. Note that Heatbath recommends an agitation speed of 100 feet per minute or more:
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How has this been working for you?

I set mine up just like this when I was having trouble getting some monster W2 blades to harden (in 8 gallons of P50) and the swirling motion of the oil made my blades warp to one side... every damn time. :grumpy:

I'd like to go back to it, if I could figure out how to make it work without the warpage.... because it did help with the actual hardening! But the warpage I got was just to severe.
 
Nick and Pat,
Make a "J" tube from 3" PVC elbows and pipe for the quench tank so the small end is in the center of the tank and the long end is up the side. The long end should end about 3" below the surface. I know you guys can rig a clamp, so I won't go into how to do that. Once it is held firmly in place, put the agitator in the down tube so it pushes the quenchant down the tube and out the short end.....directly up the center. This will quench a blade with an uprising flow that cools rapidly and avoids warp. I have used a pump with the outlet in the center of the tank bottom on a 10 gallon quench tank the same way.
 
How about something like this? Two concentric cylinders, the cool oil is pumped in from the bottom and overflows into the outer cylinder to be cooled and pumped.

 
Nick I am primarily heat-treating spikes made from cold-drawn square stock. The swirling agitation seems to lessen the warp as compared to no agitation. In my case, I think I'm getting warp because I'm not grinding the "skin" off. I say this because I don't have warp problems on the few items I make that are ground from head to tail.

I really want to avoid plumbing through the wall of my tank, which is why I'm trying the swirl approach.
 
Then you have the answer ! Grind off the decarb. You could then do a sub-critical anneal , straighten if necessary , then HT.

We had a nice laboratory quench tank .4-5 ' square with about a 5" pump in the center ,about 3' deep .Heated of course ! Too big for most of your operations but a pleasure to use.
 
.....I really want to avoid plumbing through the wall of my tank, which is why I'm trying the swirl approach. ......

That is why I described the PVC "J". It sits inside the tank.
 
Stacy - I didn't quite understand this part: "put the agitator in the down tube so it pushes the quenchant down the tube and out the short end."

I don't think think my paint mixer will generate linear flow in a PVC pipe. I read in another post that you use a 12v fuel pump. I can't submerge that, can I? Thanks!
 
Patrick,
I have looked at doing a pump driven downflow circulator, but the cheapest pump I could find was still almost $200. NorthernTool has one rated at 22 GPM. I figure parks 50 and diesel fuel are similar in viscosity. My idea was to have the pump draw from the bottom of a 3" pipe submerged vertically in the tank, so that there was a constant flow down through the pipe. Insert the blade into the pipe and the heat is whisked away to the pump/cooler. I never moved forward with it since I quench so few blades. :-) -Doug
 
If it is a paddle type, you will have to angle the blades to make it a propeller type agitator. You want the flow down the tube and out the short end. The top of the tube is about 3" below the oil level, so it has constant flow. I'll try and make a sketch of what I am talking about and scan it tonight.

I looked for the old thread I did on building my 10 gallon temperature controlled quench tank. It has a radiator and fan for cooling, and an element for heating. The pump makes the oil rise up from the center of the bottom. I also made a 2 gallon simpler version without all the whistles and bells. Both threads have had the photos expire, but the build plans are there. I will try and find the pictures at home, but I don't even know if they are on my current computer.
http://www.bladeforums.com/forums/showthread.php/396663-10-gallon-quench-tank
http://www.bladeforums.com/forums/showthread.php/396477-2-gallon-quench-tank-tutorial

OK, I found some 2 gallon photos (post #8):
http://www.bladeforums.com/forums/showthread.php/496424-Heat-Quench-Oil

Even though I have these ( and probably a dozen other quench tanks), I use a 36" tall 6" round quench tank for everything. In the new shop I will probably set the automated tanks up permanently, but for now they are safely stored in the back of the equipment shed.
For demos I use Bill Moran's quench tank. It is a three gallon coffee pot ( Remember them sitting on the cooking fires in old cattle drive movies ?) filled with Parks #50.
 
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