Welding Tips and Tricks

Hello all ,I'm just a hobby welder. a couple of days ago, welded some angle iron to a brake rotor. took a hammer to it, and it separated. used 6011 electrodes and the temp. in the garage was at 32 degrees. any ideas? here's a pic.

The brake rotor is not a readily weldable metal.

BugHunter wrote:The brake rotor is not a readily weldable metal.

I agree. Welding a metal that is not intended to be welded, in a cold temperature, with what is very likely very little amperage on a very likely very small welder that is not giving the amperage it says it is. Any combination of the above. More information is needed.

that was pretty succinct.

To the op, there may or may not be some specialty process Rod's that you could use that might work on what you're trying to do but for the most part you just can't weld to that brake rotor. Truth is, I'm a little surprised you needed to take a hammer to it.

Not all metals are weldable and even for those that are, joining two dissimilar metals is not always easy. Might not be hard but there's generally more to it than just grab the welder and a rod. If you could get the rotor hot enough to flow some brazing rod on, meaning to Tin the surface with it, you might be able to braze the angle to it then. They do make some rods for cast. If you're dead set on trying it you might stop at your local welding store and see if they have such a thing on the Shelf. And I say this assuming that the thing you are trying to make is going to be a bird feed hanger or something you're not going to swing your mother out over the Grand Canyon on.

There I reduced my succinctness

Brake rotors by themselves should be kinda weldable, but being a cast iron (most of the time) it will get very hard and brittle in the weld area so impacts will tend to break it.

Biggest issue I suspect (and to echo the other comments) is that the brake rotor is kinda massive and made to dissipate/move heat away.

So part of the issue may well be that there's little to no weld fusion on the brake rotor as it simply did not get hot enough during the welding to get any penetration going.

A bit like those pretty MIG welds that some people make that are just laying on top of the metal and break off at the slightest load.

Bye, Arno.

burnttoast wrote:Hello all ,I'm just a hobby welder. a couple of days ago, welded some angle iron to a brake rotor. took a hammer to it, and it separated. used 6011 electrodes and the temp. in the garage was at 32 degrees. any ideas? here's a pic.

Assuming the brake rotors are cast iron, you can weld to them, but it requires a rod with a lot of nickel to work....something like Lincoln's Tech Rod 55 (55% nickel) or an equivalent from another company would probably work. There are nickel electrodes with as much as 99% nickel, but they're expensive and really meant for when a weld deposit has to be machined afterwards. The 55% nickel stuff is actually stronger, but often can't be machined.

What remains of the beads look pretty cold as well...possibly from the mass of the rotor as already mentioned.

Brake rotors are straight up unweldable via most processes. They're not like gray cast iron where it's merely hard to weld. Brazing would definitely be the better option here, though your best chance with actual welding would be a 99% nickel electrode.

350 to 400* preheat, then 7018 might get you somewhere if you let it cool down SLOW.

Just don't hang 1000# pounds on it with something you want to keep underneath it (toes, fingers, etc.), cause it might work or it might not - only determined with destructive testing.

In other words, what everyone is trying to say: don't waste your time. Unless you have time to waste.

Sorry about getting back so late. Got distracted doing other stuff and totally forgot about this post until I went into the garage this evening to do some welding. will take everyone's advice. was originally welding the stuff together to use as a brace for a stool I was going to make for the garage. but saw one at Harbor freight that will serve my needs. Thanks for the responses.