Zinc/Aluminum Diecast Radio controlled airplane 2-stroke motor flange TIG build-up

[jakeru]

At the Northwest Model Hobby Expo last month, I welded a few interesting customer projects. I wish I took more pictures.

Here is one of them. This customer wanted to mount an exhaust onto a two-stoke remote-controlled model airplane engine case he had just bought, but the mounting flange was incompatible. The mounting flange on the engine was too narrow. So I just built up the material on either side of the exhaust pipe mounting flange, to make it wide enough for him to subsequently machine flat, then drill and tap holes for the mounting bolts of the exhaust pipe he had. (Exhaust pipe and flange shown pictured to left of engine.)

The metal did not weld all that nicely, seemed kind of "zincy potmetaly" so I proceeded with caution, and with as little heat input as possible and allowed cooling time in between built-up layers. I used 4043 filler rod. I dialed in a good bit of AC Balance cleaning %, to spread the heat out wide and not penetrate as deeply for the build-up operation. I did my best to keep the ugly beast of heat welding distortion away from the rest of the engine. In the end, thankfully, nothing was smoking, and the piston and crankshaft were still turning over like new.