WELDING MACHINE SELECTION

No offense, but your question is rather basic. You should assemble a matrix of all the material combinations your welder will be used for and then select the welder that will do the best job on the highest number of combinations on your chart.

One welder will not be ideal for all materials/thicknesses you will encounter.

Generally, a quality wire feed welder with different welding filler metals and shielding gasses will work on most things around the shop.

Good luck.

Most manufactures of welding machines, be it portable or fixed, have your capabilities with add ons. Try Lincoln or Hobart.

We currently use Miller welding machines. 0 to 250 amps for small machines and wleders that are 300 amps with a full duty cycle for our larger ones. The best all around is any that is ac-dc-dc reverse, selectable that allows you to make adjustments to voltage and current. If you intend to add tig, mig or a plasma cutter at some point just tel the sales staff and it will come with that needed machine adapters. Some of these machines require 3 phase current. You power source may limit your selection.

Dear Rajiv

Go for Kemppi Welding Equipment, they are suitable almost all type of welding & their technology is good enough so Power saving is much more.

Gud Luck.

kirannasare@yahoo.co.in

I recommend first that you research the methods and materials.

For example, you mention titanium. While Titanium can be welded using MIG and TIG processes, it must be back-gassed, or it will crystalize on the back side of the weld.

TIG gives you infinitely better control on delicate jobs or on materials like Aluminum that dissipate heat quickly (you need to push a lot of heat into the weld to start, but less as you continue the pubble). MIG won't allow you to adjust the heat on the fly... (Remember that you need to use AC to weld Aluminum). Of course, TIG welding is much slower than MIG.

As one poster already said, create a matrix of the materials you need to weld, noting the processes that will suit it best) and prioirtize which materials/processes are most important to you. That should lead you to a decision on the type of welder (MIG, TIG, Stick, Oxy-A).

Once you know what type of process you will run, look at the "real" welding equipment manufacturers (Miller/Hobart, Lincoln, ESAB). If you are using this in a hobby or R&D environment, don't put too much stock in the rated duty cycle of the machines. If you are in a production environmentt, put a LOT of emphasis on this spec. Whatever you buy, be sure you can get local service and supplies.

Hi hedj,

Welcome to the group.

Don't be shy, no one else is.

LL

A tig machine is your best bet, for it can do a variety of materials and a variety of thicknesses.

Rajiv, been a welder for 40 plus years and have done all tpyes of welding and the best welder as far as my experence with machines goes. Licoln 300or350D is the best have it set up mig tig stick with remote and high frequence built in. also this set give you AC,DC power and 10000 watrs of stand by ac power.

The only other Machine that will accomplish this setup is a old SAM 400 with a perkins diesel,this unit is what i use all the time. at least 60 hours per week welding.

Hi Rajiv,

I'm in the welder repair business. My first response to you is to find a knowlegable repair facility in your area and question them.

Secondly, I don't like to downplay any business, but my experience has been that even though Miller offers a whole plethora of multi-process welders, they are the very ones I see most of for warranty repairs. Their very good with warranty's but that doesn't compensate for down time. I see probably 5 Millers to any other machine.

Hope that helps.

lynlynch in a previous post has it right; assemble a matrix of needed applications and pick the machine that covers the greatest number of them.

That having been said, consider the strong points and detractions of the various types and processes.

MIG or GMAW (Metal Inert Gas, Gas Metal Arc Welding) Constant Voltage Probably the easiest to learn and the most forgiving of poor technique. Also the fastest with the least heat input until you go into the spray-arc mode. Many wires available in many sizes for a wide range of materials. Shielding gasses available to enhance the weldments of many materials. Flux-cored (FCAW) better at dealing with contaminates when used as a dual shielded process (flux in wire with CO2 as a shielding gas).

Downside: Not very tolerant of contamination. Penetration of open root weld preps not reliable, requires use of backing strips or grinding backside to clean and then fill. Flux core wires don't really start to perform in wire sizes under .045 (1.14mm), and are best on materials of at least 1/4 inch (6.35mm) thickness for full penetration joints.

SMAW (Shielded Metal Arc Welding or stick) Constant Current. The most versatile of all given the profuse numbers of alloys and sizes developed over the course of the last seventy years. Requires practice to master good technique, which can vary a great deal depending on material being welded. Heat inputs can be kept quite low, though high deposition rods like 7024 will definately heat the work.

Limitations on minimum thickness. In most circles 1/8 (3.18mm) thickness is considered the floor for full penetration joints in steel. Though rods are available down to 1/16 (1.59mm), most machines will not reliably hold low enough current levels to weld as opposed to "burning" rods. Rods are whippy at this size too. Process is dirty with flux residues and smoke, which must be cleaned before next pass. Rods for many applications need to be stored in ovens to maintain their properties. Techniques can be very specific to the application, or can vary over a broad range depending on the base material. Aluminum stick doesn't work well, I don't care whose it is.

TIG or GTAW (Tungsten Inert Gas or Gas Tungsten Arc Welding) Constant Current The caligraphy of welding. Can weld any material that can be welded. Usually used for smaller, more intricate applications. Filler alloy diameters from .030 (.76mm) to 1/4 (6.35mm) with 1/16 (1.59mm), 3/32 (2.44mm), and 1/8 (3.18mm) being the most common.

Downside: SLOW! Heat inputs usually second only to gas welding. Not tolerant at all of contamination. Requires highest level of proficency by operator. Requires back gas coverage on full penetration joints. Virtually no limitation on minimum thicknesses with current equipment, but maximum thickness limited by torch capacity and operator's ability to withstand heat. High frequency feature can raise havoc with electronics in the area.

Remember that everything is a trade-off. If you buy equipment to lay ships keels, don't expect to weld duct work with it. If your primary application is sheet metal, don't expect to lay ships keels. Units are available that switch from constant current to constant voltage. You can add a wire feeder and weld down to 1/8 reliably, and add a high frequency head to do TIG with. At up to 400 amps output, single phase input is the most common.