Copper colored Welds?

The truck is only a few weeks old. The welds are golden/copper and are hard and smooth. I'm not sure that it is rust. Does Toyota weld with a material that looks similar?

 

Surface rust, mine was the same. The welds weren't cleaned before painting. If it bothers you, clean them up and touch up with primer and paint.

 

I probably will. I haven't seen rust that is this color before. It is also smooth and hard. didn't really scratch with a knife

 

Nah it’s more likely silicon bronze welding wire used as a filler in the crunch zones so you don’t get killed should you hit something solid at speed. 40k truck they do take the time to use the right materials in the right places even though 1/2 the bitches on here think otherwise.

 

Thanks! This makes a lot of sense. How resistant is it to rusting/oxidization?

 

I would touch up the bare areas of the frame that loose paint from road trash with chassis black paint or POR-15 no rubberized undercoatings as they just trap water. Then coat the frame and underside metal body with 2 spray cans of fluid film once a year in the fall it’ll stay mint forever.

 

I've cleaned and painted all my frame welds, there's no silicon bronze. Those copperish smooth spots are silica added to the wire as a flux, it floats to the weld surface dragging impurities with it. It wasn't cleaned off before painting. It tends to crack and flake off as the weld cools, but sometimes hangs on. Water tends to get under those spots. In time it flakes off exposing the bare weld and to rust.

 

What he said ...... not a flux ..... but, yes it does "float" to the surface and can pop off exposing the bare frame / metal and then rust.
This is not silly Bronze wire. Bronze is weaker ..... it's most likely either ER70s-3 or -6 solid welding wire ( MIG ) gas shielded ( not Flux cored ).
Brush it ....... paint.
Por 15 is good stuff.

 

That would be brazing and it is not used for frame assembly. All this is is mild steel welded with standard practices that has lost some paint and has some color from corrosion. Clean it off and paint or film it and carry on. It is absolutely nothing special.

 

Whatever it is, I plan on getting rid of it and painting over it.

 

And the ER70 wire is plated with copper for storage life and is the color of copper when you buy it.
Flux wire is never coated and silver in color.

 

And the copper is so thin that it almost completely vaporizes across the arc, chemical analysis will show trace amounts of Cu if any, certainly no where near enough to color the weld beads. As a poster above said it's bare steel that rusted, and he correctly identified the causation: Silicon surfactants that chipped off after the frame paint was applied, exposing bare steel to rust. Silicon micro additions to carbon steel increases ductility.

 

Silica from the weld-wire, e-coat doesn't cover it well. I wouldn't worry about it.