1. Welding joints

2. T-joint welded using arc welding
T-joint welded using tig
T-joint welded using mig

3. Lap joint Lap joint welded using tig
Lap joint welded using mig
Lap joint welded using tig
Lap joint welded using arc welding

4. Butt joint Butt joint welded using tig
Butt joint welded using arc weld
Butt joint welded using mig

5. Conclusion
Tig welding is used mainly for aluminum it hold well and if it is a good enough weld it can be smoothed over to look as if it wasn’t even there.
Arc welding is good for thick metals.
Mig welding is used for anything between thick and thin metals.