Welding troubleshooting/help.

Padrig · Post by **Padrig** » Tue Mar 15, 2005 5:18 pm

Here is a pic of a weld I did on a tool base I am making. Obviously no petetration well maybe 1/32 or less. I am using a 115V Miller Mig at maximum voltage. Any idea? Will slowing wire speed help any? Is preheating required?

Pad

Artorious · Post by **Artorious** » Tue Mar 15, 2005 5:33 pm

That steel is way to thick for the small Miller Mig. I think the recomended maximum for that welder is 1/8" thick material?

You really need to grind the mating pieces down to hard angles and with lots of pre-heating and lots of passes you can maybe build up a weld. I'd get a small stick welder for that job.

Jurgen · Post by **Jurgen** » Tue Mar 15, 2005 6:11 pm

I probably have the same Miller welder that you do. You can weld up tools successfully with it, but you MUST preheat and you must also bevel the edges of the areas you are welding so you can get full penetration. Higher wire speed will also get you greater penetration.

Jurgen

Padrig · Post by **Padrig** » Tue Mar 15, 2005 6:20 pm

Jurgen, any idea why higher wire speed gets more penetration. I would have thought the other way around as you must go faster with higher wire speed for fear of having too big a bead?

Pad

Jurgen · Post by **Jurgen** » Tue Mar 15, 2005 9:28 pm

Its because the wire pushes deeper into the weld pool before becoming part of it.

Jurgen

Padrig · Post by **Padrig** » Tue Mar 15, 2005 9:46 pm

Ok, I see, thanks. I will try taht and to preheat with a propane torch.

Pad

losthelm · Post by **losthelm** » Tue Mar 15, 2005 10:49 pm

what shielding gas are you using?

Padrig · Post by **Padrig** » Tue Mar 15, 2005 10:59 pm

75% argon/25% co2 I believe it is with a trace of something else.

Pad

Lord Ogier · Post by **Lord Ogier** » Tue Mar 15, 2005 11:39 pm

Leave your wire speed the same. Slow your welding pattern down.

The weld you have shown is one that is cold. I.E. You didn't take enough time over a given part of the steel for the weld to penetrate.

I have welded 1/2" plate steel with a 110v Lincoln welder before by going slow and using multiple passes.

It can be done, it just requires patience.

Padrig · Post by **Padrig** » Tue Mar 15, 2005 11:56 pm

Lord Ogier, something I dont quite understand. If I slow my welding speed without slowing wire feed, dont I get too big a weld bead?

Pad

Lord Ogier · Post by **Lord Ogier** » Wed Mar 16, 2005 12:35 am

Yes, you will need to slow the feed a bit. Also, make sure you are not exceeding your duty cycle on your welder. I have seen some that at 100% power, you get about a 10% duty cycle.

You might experiment a bit with some scrap first to get the weld/wire speeds down.

I would go at a rate of about 1" every 4-5 seconds or so to start as a welding speed.

You may need to be even slower than that.

If you start having trouble with the wire sticking in the tip, use some vaseline on the tip and it should help.

Padrig · Post by **Padrig** » Wed Mar 16, 2005 12:53 am

Thanks. I guess I just need to figure how much to reduce the speed by. I am at about half the wire speed now and it seems that an awful lot of wire comes out in 4-5 seconds for 1". I'll try on some scrap as you said.

As for the duty cycle, I'll check. I agree that for these smaller machines, I may be closer to 10% at full power. Good thing that it is usually my circuit breaker (15 AMPS) that trips first. ;-)

Thanks again.

Pad