ok, so I have some steel braid and I wanted to solder the ends so they don't fray.

Is it steel or stainless steel? Stainless can't be soldered and regular mild steel is a PITA and requires special flux. Cherry hot is too hot for soldering BTW.

pretty sure its just steel, going to use it for grounding i  my car. i was getting pissed at it so i figured id just see how hot I could get it

It's better un-soldered.  Because of inductive reactance, higher frequency signals travel on the surface of conductors (known as the skin affect).  Braided cable has much more surface area than solid conductors.  It's used for ground straps because it's much more efficient at conducting high frequency noise.  If you fill it full of solder, you defeat the purpose.  Of course, if the end you're filling is a tag end, beyond the connection point, it won't matter.  As long as it's not part of the circuit.

You can roll up the end and stuff it in a crimp connector. Then crimp the crap out of it....Not sure how regular steel will oxidize (rust) over time. TT

For automotive ground strap use copper braid. Tinned is best for corrosion resistance, but plain copper braid (like from coax shield) encased in shrink tubing and sealed on the ends with liquid electrical tape will last many years. Fold over ends and stuff into crimp connector.

You can buy a 3 pack of one inch, tinned copper ground strap with the eyelets, about 12 inches long for around 2.99 at most automotive stores. You have to look in the wire section. Just a FYI

I got the stuff free from a ham, figured id use it to ground the antenna in my car, I just wanted to solder the ends so it doesnt fray. anyway, I know the rf flows over the braid, if I put heat shrink on it would that degrade performance or am  I just being stupid? I want something to protect the finish on the car

Shrink tube won't hinder performance.

Steel can be soldered but you need acid flux and I don't know how well it would work on wire rope.

The easiest way to "solder" it is to braze it with a stick of fluxed brazing rod from H-D and MAPP gas.

I think the Mapp gas will do it, if not get someone with an oxy-acetylene torch to braze it.

Another thing is that a lot of braided steel rope is galvanized, and you can solder galvanized surfaces, like a can. Be careful not to breath the fumes when you're working with it at higher than soldering temperatures, do it where there's good ventilation.

Brazed wire rope makes a great grounding strap to bolt under you car and drag on the ground to dissipate any charges from EMP strikes.

Or you can use a piece of chain.

Oh, don't sweat the RF 'flowing over the ends', not an issue.

Another idea is to go to H-D, etc, and get a large crip terminal and crimp it on the ends. That's the easiest solution for cosmetics. Then put shrink or vinyl tubing over it /or before...