Welders

[Dan@DB-Power]

HI All

Looking to buy a welder. Anyone know what the difference between and arc and a mig welder?

Also will a arc welder manage to weld exhaust pipe together?

This is the welder I was looking at:- Arc Welder (http://www.machinemart.co.uk/product.asp?p=010111027&r=2032&g=105)

Cheers
Dan,

[Wak]

Arc welding and mig welding are similar in that they both use an electrical current to melt a filler material into the two parts to be joined making one piece. The main difference is that with arc welding the filler material comes in sticks which get shorter as you weld, but mig has the filler material on a roll inside the welder and it is fed out into the joint as you weld. This means that arc welding is more difficult because you have to move the torch toward the workpiece as you weld as well as along the joint. Also with arc welding the stick is 'live' all the time so as soon as you touch it against the workpiece the arc is started (in theory, but the process of starting the arc without just sticking the rod to the workpiece is actually quite tricky) Mig welders only start to weld when you pull the trigger so starting the weld is much easier.

With both kinds of welding the filler material needs a shield to avoid picking up impurities during the welding process which leads to a poor weld. Arc welders do this with a coating on the rods which covers the weld as you go and you have to chip off with a hammer afterwards, mig welders with a curtain of inert gas such as co2 or Argon around the welding arc which produces a finished weld with no need for chipping off.

Both types of welding will weld exhaust pipe, as long as the pipe isn't galvanised or zinc plated, if it is this makes welding even more tricky and gives off fumes even more noxious than those usually given off by the welding process.

I would recommend a mig welder for the following reasons-
-It's easier to do if you are a novice
-It's more suited to welding the thinner guage steel found on cars, when you weld thin steel you have to turn the power of the welder down to avoid blowing holes in the steel and the lower the power the more difficult it is to start the arc with an arc welder

Unfortunately mig welders are more expensive than arc welders:(

Don't be tempted to buy the 'no gas' migs which have a flux cored filler wire, they're not that good.

If you buy a mig get one with the capability of taking a large co2 bottle, the small ones you get with them last 5 minutes and are the same price as a big bottle from BOC

Wow - is this my longest post?

[Dan@DB-Power]

Cheers for the info Wak.


I will research more.

Cheers
Dan,

[Wak]

No probs :D

[A8 YOB]

I have a Clarke 100e mig, had it years and its easily payed for itself now.. if you get handy at welding(basically if you can draw a line with a felt tip you can mig weld) its very easy to make a few quid on the side.

Do get it converted to run pub bottles though, the disposable Co2 cartridges are very pricey and bloody useless.. about 8quid.
If you're planning on doing a lot of welding, ie. restoration consider one of the 'turbo' models.

Heres a link to the 100e http://www.machinemart.co.uk/ranges.asp?g=105&r=2029

[Wak]

Originally posted by A8 YOB

Do get it converted to run pub bottles though, the disposable Co2 cartridges are very pricey and bloody useless..

That's what I've done:)