Welding Tips and Tricks

Been welding for 30+ years, wire feed, gas, and stick. Usually so much time between projects that it takes me the whole new project to get back to where the welds are presentable. I can do structural. Not pretty until the second day.
Ran across a deal on an old Miller 300. Not a beginner machine and wondering if it is going to be too much for the garage shop to handle. But game to try. Looking at a weekend class in December to get my feet wet. In the meantime, going to try to soak up as much base information here as I can.

Been so long that I've looked at the machine that I'd forgotten what it is. It's a 330A/BP

There are some users of that machine here, and they rave about them.

Welcome to the neighborhood!

Steve S

This one was straight out of an aviation repair shop down close to the Atlanta airport. They were switching over to a suitcase size one that wouldn't be such a power hog. Rolled it onto my pickup and then into the back of the garage. Haven't even figured out how to hook it up yet. Not sure I have enough power available. The house line maxes at 50amps. Another alternative is to run some heavy cable and tap into the backup generator for the house. That has 22kW available.

Rickster, welcome to the forum.

How ya doing Rickster,
I used to work over there by the airport at Zappa's Precision Welding.
Personally, I would just just plunk down the cash for some #6-2 stranded copper wire, pvc conduit and electrical box, then run that wire underground and have myself 60A @ 240V on tap. Unless you plan on rarely ever using it then the generator is not a good idea. Just tap those lines into the main legs of your home's electrical service and you'll be go-cat-go.

Ran down to the basement and checked and called the electrician. That's what's there now. #6-2 and 60 amps. Plenty to run half speed and take care of any all the steel I will likely do. Was thinking forward about what I was going to need to do aluminum. Maybe getting ahead of myself but month and a half to the class I signed up for and wanted to be not chasing Craigslist deals to get rolling.

If you need to double it then just run another identical pair and add a breaker to match. Eazy-peazy. That would give you 120A @ 240V. 15% - 20% safety margin would set you comfortably between 95A & 100A. Just be aware that those old transformer machines are super inefficient and will really jack up your power bill if you use it much. If you're ever able to justify the cost of an inverter based machine, you won't even notice a difference on your power bill. Yeah, there really is that big of a difference in power consumption.

Well then, the question becomes whether a newer, efficient machine would do aluminum projects on 60amps and how long the power difference cost would take to pay for a newer model. Or a new model. Compared to the 330A/BP with the foot controls and water cooled torch, already set up. My most ambitious projects have been trailers, but wouldn't mind expanding to aluminum and stainless boat parts and a new dock walkway, eventually. So a switch would also save cost of upgrades to the power supply.

Where north of Atlanta do you live?

My machine puts out 250A @ 60% duty cycle of Aluminum smoking power from a mere 30A 240V input. It set me back $2500 plus $450 for the water cooler. You can get the same power out of an Everlast 250EX for $1700 but it doesn't have all the bells and whistles that mine does. Don't wory cause you won't need em in most cases. There is also someone on this site who is an AHP dealer and you may be able to score the same power even cheaper. If you wanna weld aluminum then you're gonna need at least 200 amps on tap but more is better if you wanna weld thick stuff. I bought my machine with the idea that I would be able to weld at least 3/8" aluminum but it is easily capable of much more.
You have a good machine, albeit a power hog.
Inverter machines weld much hotter on advanced square wave than do square wave or sine wave transformer machines. They're a shitload more efficent. They also alow you to test sine wave, triangle wave (an inverter only function) and soft square wave to see the differences side by side. Advanced square is at least 10% hotter than soft square.

Flowery Branch. Used to be a creek. Now suburbs and no creek and the flowers are in pots.
Maybe a surplus of machines. Using a little Century for MIG and a restored barn find old Forney for stick. Now the big Miller 330a/bp which could do all but doesn't have all the accessories. Second guessing myself about liquidating and getting one that does everything. May see how the "new" Miller runs first. Fantasies about a newer machine that doesn't require scrounging parts. Got one of the last cooling fans in existence for the original early 1950s run for this model Forney. WAY back in the warehouse.