Heating Element Replacement in a Vintage Saeco Lead Pot

by Aaron Bittner

Some years ago, though I didn't know it at the time, I was given a great gift. The gift was a rusty Saeco bottom-pour lead pot. At the time my Lee Production Pot had given out, and I was just glad to be casting again. I thanked my benefactor profusely, and got back to work.

It wasn't long, though, before I had some trouble with the thermostat. When it finally gave out, I replaced it with a Lyman unit of nearly the same age. It was a very different thermostat, but a direct replacement for the older Saeco. Still, I was having trouble. The wiring that connected the thermostat to the heating element was multi-strand copper, and as it heated up it oxidized, and as it oxidized it lost conductivity strand by strand, until finally the whole wire burned through. This problem was especially bad at the connections right at the ends of the heating element, the terminals of which were stout steel wire of about 14 gauge, a half-inch long or so.

Try as I might, I could not get a reliable, heat-tolerant connection to the heating element, and after futzing with it for the twentieth time I finally broke off one of the terminals. "Put a fork in me," I said to myself, "...because now I'm done for sure."

As it turned out, however, new of my demise was slightly exaggerated.

After entertaining options (Buy another Lee? Find a replacement Saeco or Lyman pot? Get the old pot rebuilt by a pro?) I hit upon an idea which I thought would work, and which I knew wouldn't break the bank. A kind soul at the Cast Boolits Forum alerted me that McMaster-Carr could probably supply a replacement heating element. After browsing their extensive website, I concluded that it was worth a try. How much harm could I do? It was broke already, right?

So I ordered McMaster-Carr item 3540K36, a flexible, hand-formable immersion heating element, 36 inches long, .260 diameter, with a power draw of 750 watts and an upper temperature limit of 1700 degrees. I knew that the power range was close to right. I thought about going with the 40-inch-long, 850-watt 3540K37, but elected not to because I thought I needed the 36-inch element for the placement of the ends to come out right. I was wrong, as it turns out...but that's getting ahead of my story.

Figure 1: The McMaster-Carr heating element as it arrived from the company. A flexible plastic sheath covers the terminal on each end.

Figure 2: The replacement heating element's terminal connections.

As you can see from Figure 2, the electrical terminals on the replacement element are quite robust. I was gentle with them anyhow...I didn't want to take any chances. The white cylindrical object in the photo next to the terminal nut is a ceramic insulator; it acts as a spacer to keep the wire connections both thermally and electrically insulated from the heating element body.

The next step was to get out the Saeco pot and start taking it apart.

Figure 3: The patient. (Pay no attention to the feet of my assistant Susan, who helped me to take the photo.)

Figure 4: The heating element terminal in this photo is broken off too short for an electrical connection.

Figure 5: Initial disassembly of the Saeco pot.

Figure 6: The bottom of the pot.

Figure 7: Removing the three sheet-metal screws that hold the bottom housing on. Note that the stand legs have magically reattached themselves to the pot proper; this is what happens when you take your photos out of sequence.

There are three sheet metal screws that attach the bottom housing to the side housing. Now is a good time to remove them.

Now, much as it may pain you, you'll have to take a pair of wire cutters or small sheet metal shears and cut the steel retaining straps that wrap around the lead pot's side housing. You'll replace these straps at reassembly with some good-quality stainless steel hose clamps...the house-drain size is the one to get.

Figure 8: Cutting the retaining straps.

Figure 9: The bottom housing is removed.

Figure 10: Cutting the inner heat shield restraining strap.

Figure 11: Pot assembly with old heating element still in place.

From here it's fairly simple to lift the old heating element off the cast-iron pot. I took a moment to consider how the element was bent, but elected not to use the original arrangement.

The problem was that the original heating element was bent quite tightly, making fairly small loops and whorls all over the outside of the pot. The McMaster-Carr replacement, however, was rated for a minimum bend radius of only a hair under an inch. That's a loop diameter of two inches, bigger than the original element, and too big to permit the same element geometry. The upshot was, when I finally took the new element in my hands, it was entirely in my hands if you know what I mean.

I took a picture of the old heating element just because it was interesting to look at (Figure 12). Note the original element's loop that wound under the bottom of the pot and which came quite close to the pour spout; this would be difficult to impossible to duplicate with the replacement without exceeding minimum bend radius considerably.

Figure 12: The old heating element and the pot it rode in on.

The Moment of Truth

Now the moment of truth had come...it was my task to take that McMaster-Carr heating element in my hands and make it fit the Saeco pot, without destroying either the pot or the element.

There wasn't any point in being timid about it, and waiting wasn't getting it done, so I picked up the element and started forming. I found that a low-hanging tree branch of the right diameter is useful here for controlling the radius of the bend. I also bent the element around the pot itself. The initial bend looked something like Figure 13.

Figure 13: The initial bend (side view).

Figure 14: The initial bend (top view).

Figure 15: The second loop of the element.

Figure 16: The finished winding (side view).

Figure 17: The finished winding (top view).

Figure 18: Reassembly begins.

Figure 19: Reassembly continues.

Figure 20: Reassembly continues.

Figure 21: The assembled lead pot.

But How Does it Work?!?

Pretty well, thanks.

Well, on the first melt I burned through one of the last remaining pieces of multi-strand wire in the thermostat assembly...remember, that was the problem that caused this whole project to be necessary?...and, rather than take the rest of the day fiddling with the thermostat wiring yet again, I wire-nutted the leads to a piece of heavy-duty lamp cord, plugged it in, and 20 minutes later I was casting bullets.

I did notice that it seemed to take a little longer to heat with the new element than it did with the old. I believe this is because the older element is slightly higher in wattage than the new one. Also, I would have liked to have had a piece of heating element closer to the pour spout. That spout on the bottom of the pot is a cold spot, one of the last to melt, and putting a little heat near would help.