im looking at getting a 2nd hand welder to do odd job on car as for 1 not happy with front mud guard frames as there very weak so what best to nuy a mig or arc?

Have you welded before?

They say that MIG is easier than arc but I found it to be the opposite.

It is easier to use arc outside.

Arc good for thick metal (4mm??? plus) Mig way better for thin stuff. But lots of duff types around. Look on teh mig welding forum for best advice

You will need a mig, 100amp ones are not worth it look for 150amp.

You also need to budget for a proper gas bottle and gauges as the little hobby bottles do not last and cost £££

have welded over the year and would have free supply of wire/rods as i work in steel works

theres 2 local a sealey arc welder and a kennedy 120amp mig

This R-Tech ticks both boxes and the customer service is amazing, they even do 0% Finance over 6 or 12 months

http://www.r-techwelding.co.uk/welding_equipment/Mig_Welder /Mig_Welder_R-Tech_IMIG180

Buy a good secondhand one. I have a murex 251, biggest available on single phase, cracking welder!