Dabney Becomes Firmly Grounded
The day started out without incident for Dabney. He was in the garage and rather excited about the job he was going to undertake this
morning. You see, he had done all the homework and measuring, and had cut out some of his 1940 Ford's frame to retrofit it with a modern Mustang front suspension.
This task was not without its risks, however, since Dabney knew that the new frame pieces must be welded in solidly or the car's frame would collapse during driving. He had gone through his MIG welder and associated equipment the day before to make sure everything was working properly.
As he was making the first tack-weld on the clamped-up assembly his welder tip started sputtering and splattering, a sign of a poor weld. He readjusted his grounding clamp and set the welder to a hotter (current) level, then tried again...
"Drat!" he screamed, "I can't get a good weld!"
Just as he was saying this he heard the Doctor approaching. The Doctor heard the scream too, and shielded his eyes as the torch made contact with the metal.
"That's quite a hot spark," said the Doctor, "and it looks like you've got plenty of current flow, Dabney."
"I do, Doc," replied Dabney, "but this contact makes sloppy, weak welds. I've ground off all the rust on the old part of the frame and made sure the welder's ground clamp touches it as well as the new metal, but the thing just keeps sputtering."
"Give me a welding goggle and let me see what's going on as you make contact," said the Doctor.
Dabney gave the Doctor a spare welding mask and proceed to make another attempt at joining two sections of frame. The same thing happened again, with increasing frustration on Dabney's part.
"This is a bad ground problem, sure as I'm standing here," said the Doctor.
"You're sure, Doc?" said Dabney, "because I'm out of other ideas myself."
"Let's look at the metal surface and how things are clamped up," said the Doctor, "and meanwhile you and the welder can cool off."
They examined the two surfaces to be joined. Both were ground fresh and shiny and both were butted together, with a wide welding clamp holding them tightly. Most often, clamping the welder's ground to the attaching clamp helps ground both sides, but in this case it didn't. The Doctor inspected the welder's clamp to make sure the wires were tight and not corroded. Everything looked fine.
"Well, I have to admit this one is a bit of a challenge," said the Doctor.
"It sure is," said Dabney, " and these welds are the most critical kind.
They have to hold the car's frame together perfectly. Otherwise the whole assembly will collapse. We need to get another welder and try it out."
"Not so fast, Dabney old boy," said the Doctor. As he spoke he started looking around the shop, concentrating on the problem at hand. Dabney knew when the Doctor was puzzling a problem, so he didn't disturb the thought process.
Shortly thereafter the Doctor walked over to the side wall and grabbed a set of heavy-duty jumper cables. He brought them over to the car and moved the welder's ground clamp to a section of new frame metal, then firmly grabbed it with the clamp's teeth. He then clamped one end of the jumper cable to the welder clamp and the other end to a cleaned-up portion of the old frame.
"There, let's see if the system is grounded now," he said.
Dabney turned on the welder and both put on their masks. The welding tip arced on the joint and began producing perfect welds. The problem was solved, and both learned a new trick.