butt head, butt weld.., I need some help Options

[TravisNeff]

Hey all,

I have been trying to patch up A/C holes in my tub and having a helluva time blowing holes in the metal and voids around the weld area. I start with tacks in the corners and start tacking around the world in an offset pattern, when I have about 12 tacks in a circle I try to join the tacs. However when I tac, I most always blow a hole in the new sheet metal, or in the old panel. I have the worst time in the vertical position. I have ground down both sides of the panel (and patch) to clean metal. If I am not blowing a hole, only about 50% of the weld gets good penetration, when I hit it a little longer I blow a hole. I have even used a sorta chill bar to back the joint (1" copper pipe squished flat with a bend, suggested by another lister). Also, I am making most of my holes just buzzing a tack, not so much once I have an arc established.

I have a Millermatic 175, using .023 wire and Argon/CO2 (about 24lbs pressure when I hit the switch), Guide states I should use #2 on voltage and 50 on the wire feed speed. I have no problems welding lap joints at these settings and it sounds like bacon frying when it does it, so I know I am close.

I have gone down to 1.5 on voltage and reduced the wire feed to 40, still no luck. I have expanded my stickout (experimenting with 1" plus down to the 3/8's I normally do). The welds suck. Once I get done and grind the welds down smooth I almost always find a crack/void where the metal joins the weld. Weld, grind, weld grind. I can eventually get it right, fixing each one of the patches once I grind it down. I have tried the butt weld clamps, but the gap is huge, I can get the metal to almost (or actually touch) and hold it in with a magnet.

What am I missing? Should I be using metal ready to clean the metal even further, try another technique? I am holding the gun at an upward angle and a touch over to the side (hell I have tried just about everything).

[Mueller]

it's just practice...are you making little circles when you weld??

with enough practice you should be able to fill up a 1/2" hole with nothing behind it (I don't like the "chill" bar method)

is it windy near your welding location? your shielding gas could be getting blown away???

[TravisNeff]

Ahh practice, I have been doing a lot of that. When I refilled my tank at my local welding store after 4 weeks (80cf), he said I must have been very busy! However not a lot of butt welding in a veritcal layup - that is next.

No wind, in the garage and my mouth breathing while welding is not affecting anything either with my nifty autodarkening helmet.

I tried the chill bar and only helped me a little bit, I mostly do without. Seems as soon as I blow a hole, then try to fill that hole (letting the metal cool or not) just blows the hole bigger, that is why I am questioning contamination on the metal surface.

[TravisNeff]

Oh, no little circles - I will try that. I am almost closing the gaps with tacks (like they are almost touching, then hit the spurs to it once around the hole (in segments).

[TimT]

Sounds like to much juice, even though the book say use settin #2. try a lower heat setting.

oh and practice!!

(IMG:http://www.914world.com/bbs2/html/emoticons/smash.gif)

[MarkV]

I have been going through the same thing. Using a Lincon w/ .023 wire CO2/argon my machine calls for C voltage and 2.5 wire speed. I discovered that if I increase the wire speed to 3.5 that the penetration isn't as good but it works great for filling pin holes.

I shoudnt have tried to butt weld this:

[Eric_Shea]

After reading the first post I would have said slower speed and less voltage. I think you may just want to slow the wire down a bit.

[SirAndy]

QUOTE (Eric_Shea @ Feb 14 2005, 03:20 PM)

After reading the first post I would have said slower speed and less voltage. I think you may just want to slow the wire down a bit.

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) plus, practice the circle motion when filling a hole. it really helps ...

(IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif) Andy

[Root_Werks]

Yep, a lot of times you can have the voltage about right and the wire speed will feed faster than it can melt, punching holes. Low voltage, slow wire speed, little circles. You can almost see a little "horse shoe" when you weld. (IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif)

[Mueller]

QUOTE (SirAndy @ Feb 14 2005, 04:24 PM)

QUOTE (Eric_Shea @ Feb 14 2005, 03:20 PM) After reading the first post I would have said slower speed and less voltage.  I think you may just want to slow the wire down a bit. (IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) plus, practice the circle motion when filling a hole. it really helps ... (IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif) Andy

as Jack Burton say's "it's all in the wrist" (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[chunger]

I thought jack burton said, "It's all in the reflexes".

(IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

[riverman]

Try and have a small gap between the two pieces of metal your trying to join (1 or 2mm) and turn down your voltage and turn up your wire speed. It won't burn as hot (less blowouts) and it will deposit more filler metal into the gap. You'll have to play with your settings to see what works best on your machine.

[MarkV]

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) If I slow the wire down the welds look better but I make a new hole at the edge of the hole I just filled. More wire speed is the ticket for me.

(IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif)

[John Kelly]

Also try welding more briefly. A quick zap, then another. If a hole opens up, aim the wire at the edge of the hole, zap, wait, zap again...

John www.ghiaspecialties.com

[Trekkor]

I don't understand why everyone wants to do butt welds. Especially in "invisible" areas of repair.

Lap welds are faster and may even be stronger.
I noticed the other day, all the lap welds in the construction of the body of my car. They're everywhere.

Might be tough to even find a butt weld (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

KT

[IronHillRestorations]

What everyone says about technique is right. Practice with the same kind of metal you are welding on the car, and go ahead and blow holes and weld them up. It's the only way you are going to get the hang of it.

Another thing you can try (off the car first of course) is to run about 3" of wire out before you make your arc. It takes a little bit of practice to get the hang of it, but it helps keep it from blowing holes.

I use a copper spoon to weld up holes, when it's possible, but you've got to work on that technique too, so you get good penetration and everything is stuck together well.

Makes me think of the first time (20 yrs ago) I tried to weld sheet metal, and NOT with a wire MIG. Had one of the venerable old Lincoln 225's, great for stick welding 1/4" thick or more, but take a small electrode, turn the amperage down, and POW it'll blow a hole through 20 gauge sheet metal the size of a half dollar in the blink of an eye. Oh jeez....wtf....oops did I do that (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)

A lap weld can be an acceptable repair, as long as the lapped side of the joint isn't exposed to moisture. This is hard to pull off on a floorpan unless the car is on it's side, or upside down. I would NEVER lap weld flairs, I don't car what any body man says. Talk to any quality restoration shop and see what they say.

[xsboost90]

yeah, lay off he juice...or speed and volts that is. When its right youll be able to tell, you can fill in holes like a ice cream sundae maker.

[Mueller]

QUOTE (trekkor @ Feb 14 2005, 06:30 PM)

I don't understand why everyone wants to do butt welds. Especially in "invisible" areas of repair. Lap welds are faster and may even be stronger. I noticed the other day, all the lap welds in the construction of the body of my car. They're everywhere. Might be tough to even find a butt weld (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) KT

that "invisible" part can come back and bite you in the @ss, you cannot see behind the lap joint and if the material was not coated correctly before and after welding, any moisture that gets back there will cause rust down the road.....a butt weld has no "hiding" places.....yes, a lap weld can be a lot stronger due to you having more surface area for welding....you will find some rust behind some of the lap joints the factory did.....

..as with any kind of repair or job, there is normally more than one way to do it...

[Trekkor]

So I'll have to replace the battery tray and area again in 30 years. (IMG:http://www.914world.com/bbs2/html/emoticons/lol2.gif) O.K.,Maybe 20 (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

I don't know how to rust proof steel forever.

First one who does gets to be the richest person on the planet.

KT

[MarkV]

I just did it for cosmetics. Now that I spent 3 hours grinding it should be kind of invisable. Did a lap on the top of the long w/ 16 gauge & blended it in.