Water Pump Project: Welding Dissimilar Metals

Water Pump Project: Welding Dissimilar Metals


Hello, my name is Darrell Reed. I’m the fabricator at Ilmor Engineering. And I’m Andy Weyenberg with
Miller Welders Motorsports. Today, we’re working
on a water pump project for our 396 stock car program that we modify for proper
fitment in the race cars. Warning: Read and follow all labels
and the Owner’s Manual. The project is comprised
of a casting water pump and a 6061 tube that
gets modified and welded to the water pump. The challenge with this is that you’ve got two dissimilar alloys. You’ve got the A356 casting, and you’ve got the 6061 tube that he’s gonna be welding to the casting. That presents a problem when selecting the proper filler metal because we have a couple different things we have to work with here. We have two dissimilar materials and we have an engine area
where it’s extremely hot. So this would be considered a
high-temperature application. Selecting the proper filler metal for your application is critical. There are a lot of tools on the market for selecting that filler metal. The one I like to use is from Hobart and it’s actually an app you
can put right on your phone. In this case, the proper filler metal will either be a 4043 or a 4943 filler metal. To start this process, we
receive a raw water pump and we end up cutting the snout off, so we get proper fitment in the race car. The next process would be we’re going to take this tube and we’re going to trim
it to the proper size to fit our jig. We’re going to roll a bead on the end. And the next process would
be our finished piece right here that we’re going to weld. Now that I have my pump and
my tube clamped in my jig and we’re tacked in place, we’re ready to perform the first weld on this side of the pump. For this project, we’re
using the Dynasty 400. He’s got his main amperage
set at about 220 amps, which he’ll be regulating
with the foot pedal. His balance is set at 76 and his frequency is set at 65. That lower frequency setting of 65 will give him a wider puddle profile. He’s using 1/8-inch 4043 filler metal for the first pass on this water pump. Now that we have our pump and our tube attached in our jig, we’ve completely welded as much as we can. Now we’re ready to come
out and finish on the bench. As you may have seen,
our first pass was done with 1/8-inch 4043 filler rods, and then we switched to
a 1/16 4043 filler rod for our weave bead. Always remember to use a
dedicated stainless steel brush when you’re welding aluminum so you get no cross contamination into the softer material. Otherwise, you’re going to
contaminate your weld. Now that we’ve completed our water pump, we’re ready to go racing. And for more information
on the Dynasty 400, check out MillerWelds.com. And for proper filler metal selection, download the Hobart
Welding Calculator app.

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