spot welding problems

[Baeleron]

Has anyone had any difficulty spot welding rails on a M70 flat? I'm using the 120V Harbor Freight welder. When it's welding, the area around the tips doesn't light up as much as it should and the welds are weak. Is this thing too underpowered for 1.5mm flats? It seemed to work fine on regular 1mm flats. Any suggestions?

[kcstott]

1. contact area on tips where they contact the rails and receiver need to be clean and shiny, Contact area of the tongs where it goes into the spot welder needs to be clean and shiny

2. receiver and rails need to be clean and shiny degreased no oil

3. welder needs to be set up to provide good firm pressure

4. then you will need to plug it into a circuit that has next to nothing else on it.

then get everything set, clamp the crud out of it and give it a good five to eight count but watch your heat, you should fell the metal give once it's up to heat if you don't feel it give you didn't get it hot enough.

[edgerly779]

If your ever in sfv I have a commercial 15 kva spot welder that does spot welds in 1 second. pm me.

[jmpgnr24k]

Get a hold of someone with a 220V spot welder

[Alex$]

As KC said, clean and hold. 120 is enough

[Baeleron]

I did what KC said and it seems a lot better now. I suspect my main problem was not clamping it hard enough. Thanks guys!