Welding Tips and Tricks

First, I'm not a welder but I'm building a custom motorcycle and just brought home some CNC machined brackets for the frame-to-motor mounts. They are 3/8ths mild steel and are covered in the coolest machine marks which I want to preserve so I'm thinking electroless nickel plating (no copper used) to stop rust. If I nickel plate them can they be welded to nickel plated chrome-moly frame tubes and nickel plated mild steel motor mounts? With stainless rod??
Thanks for your help!
Cheers.
Ross

I'd use nickel TIG rods, not stainless rod. I'm sure there are some 312 or other "wonder" rods that would also work, but the cost might be excessive.

Are you also doing the plating for the tubing and other parts yourself??

If not, I'd be concerned that what was advertised as "nickel plating" on those parts may actually just be mystery metal junk, and that would provide you with a bad day when trying to weld over it. Just something to consider of you are buying those parts already plated.

Edit: And FWIW, personal opinion, it's just not a great practice to weld over plating in any circumstance. The right answer is to remove the plating around the weld areas, weld, and then replate as needed. Even if you weld with a nickel alloy filler, you will still introduce a large amount of ferrous material into the beads and that will likely show some corrosion over time.

Thanks cj and spartan! I was going to have the parts electroless nickel plated but I wasn't aware of the iron mixing in the weld and causing corrosion later. Makes sense. I'll have to find out if they can plate everything after it's all welded together. Thanks again for your input, I appreciate it!

I would be most concerned about matching the chrome molly to the steel for picking a filler.

Poland308 wrote:I would be most concerned about matching the chrome molly to the steel for picking a filler.

You don’t think ER70 would be fine?

It might be fine but it would depend on part thickness weld size and joint configuration.

I don’t like tig welding plated parts as it often causes problems later on.

Fancy machined parts also send up flags. Cnc can get very cool machine marks that them selves are not an issue. However there are leaded steels that machine were nicly but are next to impossible to weld due to the lead. Stainless steel can often be machined nicely especially 303 as it doesn’t work harden as much as other stainless steels.so best ask to make sure of the type of steel you have.

Drag race cars are not permitted to have any chrome or nickel plated critical parts due to hydrogen embrittlement. Years ago plated parts were common. I know bikes have tons of plated parts and don’t seem to have issues. Possibly the platers know their stuff and take corrective actions. I had a plated spring break on my street rod that nearly cost me the car. A friend broke a similar spring from the same mfg the following week that caused a fender to get ripped off his streetrod.

Byron