you need to have it hot enough to penetrate your thicker steel without burning through the thinner stuff. so focus most of you puddle on your thicker metal with quick even whips onto your thinner plate
i have been a welder for almost 20 yrs now and have master any type of welding possible. if you are looking for a buzz boz (small welder) lincoln or miller would be you two best choices but dont over look the hobarts. its a great bang for your buck and reliable for a lower price than the miller...