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Topic Review (Newest First)
08-15-2012 04:59 AM
vw nut NICE WORK! If you follow what the rest of the guys are saying you will be on to your next profession, restorations. I do not like the "kitty hair" stuff. I have been using an epoxy based product, West System. I use it at work for repair SMC panels on trucks. Kinda like polyester resin based but sticks good. If you mix some Cabasol with it you make a paste that will fill those nasty little holes. Just use epoxy prime and your filler primer as normal. Good luck. Great looking work.
08-15-2012 12:09 AM
Elevinpointsixtoone What Old Fool said above is spot on. The only time I have craters is when I have too much heat from: holding the trigger too long for 1 tack, hold the tip too close to the material. The less expensive welders with the heat tapped dial is harder to finesse on the low end of the heat. You might think about jumping up to a continuous adjust heat type MIG....Lincoln SP series is what I use for sheet metal and the Handler 220 for the heavier gauges. I saw someones start this thought...try running the tack slightly to elongate it. Like making 1.5 tacks. Pushing the puddle along after a cold start will create better penetration and usually a flatter smaller weld bead than a fat tack. Lots of good info above....I love welding!
08-14-2012 10:00 PM
r0cket88 Hey, you do very nice work. I get those sometime. thanks for posting there is a lot of great tip here.
08-13-2012 01:23 PM
Mach1460 A little late I know, but im having the same issue and am worried about problems coming up later if I just epoxy'd over the small "craters". So if I can sum up what ive just read: The small dimple/craters are ok to epoxy over and use some filler if there noticeable? No need to worry about corrosion and or problems in those areas since there "sealed" from the welding gas?
06-24-2012 06:43 PM
Old Fool
Quote:
Originally Posted by MARTINSR
I learned this from some reading material or class somewhere. I just ran across it recently but I can't remember where. You make perfect sense but this is what I was told somewhere. I will still cut it off just because it makes a better weld in my opinion but I understand the oxide part of it isn't accurate and I will quit passing on this erroneous info.

Brian
Yup, cutting it off makes for easier starts.
06-23-2012 11:00 PM
MARTINSR
Quote:
Originally Posted by Old Fool
Another point, the ball left on the end of the wire after a weld is NOT oxide, it is not corrosion, it is not rust. It is the ball of metal that formed and was ready to transfer to the weld zone.
That little ball was formed inside of the inert gas shield and solidified in the inert gas shield. It has not been exposed to the ambient atmosphere while in a molten state.
IF it was rust, oxide, or what ever , then all of the weld would be as it to was formed in the same shield gas as that little ball, and was even exposed to the atmosphere before the little ball was.
I learned this from some reading material or class somewhere. I just ran across it recently but I can't remember where. You make perfect sense but this is what I was told somewhere. I will still cut it off just because it makes a better weld in my opinion but I understand the oxide part of it isn't accurate and I will quit passing on this erroneous info.

Brian
06-20-2012 05:29 AM
Old Fool

The "pin holes" are the crater dimples. What you are seeing is not porosity. Most all the suggestions are aimed at addressing porosity.
Take a good look at the tack welds in the photo. You have a crater in every tack. Some of your tacks are 50% thicker than some of the others. All have a crater. When ground down the crater disappears in the taller tacks, and a portion of it remains in the shorter tacks. Look closely at your finished part and you will see the indentation (pin hole) is in the center of your weld material.

You need to resolve the crater depth issue, either by adjustment or increased puddle height.
Try holding the torch at a 10 degree angle instead of straight on.
Too much shielding gas can be cause, 14 should be adequate.
Arc length is another source.
You mentioned grinding off the nozzle to see better, which sounds like you are shoving the gun down to close.
Put a new nozzle on and try to hold back a little bit.
Start with a short 1/2" of stick out and try and maintain that length.
Do not shove the gun towards the puddle, let the wire feed to the puddle.

Another point, the ball left on the end of the wire after a weld is NOT oxide, it is not corrosion, it is not rust. It is the ball of metal that formed and was ready to transfer to the weld zone.
That little ball was formed inside of the inert gas shield and solidified in the inert gas shield. It has not been exposed to the ambient atmosphere while in a molten state.
IF it was rust, oxide, or what ever , then all of the weld would be as it to was formed in the same shield gas as that little ball, and was even exposed to the atmosphere before the little ball was.

One more thought, is your ground wire hooked to the plus terminal inside the welder? (straight polarity)
Ground should be hooked to the minus terminal. (reverse polarity)
06-19-2012 06:53 PM
SublimeRT Wow, this thread took off a bit huh? Lemme see if i can provide some replies. I have yet to try to remedy the pinholes but when I do I will take some suggestions from this thread.

Quote:
Originally Posted by tech69
just throw some kitty hair in them or just tack them shut. you're a damn good welder btw.
Thanks for the compliment.

Quote:
Originally Posted by rusthater89
Yep, I do the same thing

You can just go over the spots with the welder backed with the copper piece.

Or you can just fill the pin holes with fiberglass. I did that with my old car back in vocational class when I had the same issue as you and it came out fine.

What did you use to grind the weld? It looks really neat.
I have a copper spoon I use on edges and corners. I've tried to tack up these little craters before and I'll grind down my tack and there's still a crater there. I will experiment though. I really dont want any fiberglass or filler anywhere there shouldn't be in the first place.

I will knock down the majority of the weld with two thin cutoff wheels stacked on a die grinder, then level it off with 3" and 2" 3M 80 grit roloc sanding discs on my BluePoint right angle whiz wheel, then finish it off with a fresh 2" brown coarse 3M strip disc. Sometimes in hard to reach nooks and crannies or for very fine work I'll use a dremel with the appropriate sanding wheel/cutoff wheel/strip disc.

Quote:
Originally Posted by Old Fool
Looks to be a crater in the center of some of your spot welds.

If so, You need either to turn up the wire speed a bit or hold the trigger for a moment longer to fill the crater that forms in the center of the puddle.

Can't see, put a cheater lens in your helmet, makes a world of difference for old eyes. It makes things brighter for my old eyes. Another trick Shine told me was to put a spot lamp shining on the weld zone, and it does help.
I'm afraid if I hold the trigger long I'll blow holes in it. I've had plenty of experience with that to see when it's coming. Maybe some more wire speed like you suggest will help though. I can read about it all day long, but I'm still getting a feel for the effects of wire speed changes. These eyes are only 27 so far, but I had never heard of a cheater lens. Could help, thanks. I always have a drop light shining on my work too.

Quote:
Originally Posted by MARTINSR
The work you are doing is absolutely TOP KNOTCH! Very nice work, my question is if these holes are going thru? If they are simply craters you are so close to PERFECTION it isn't funny.......................................restor ation work (my own car) so I can have fun with it like you are. Doing regular old collision work every day you loose some of your passion, YOU have some passion that is for sure.

Let me make this perfectly clear, that work you are doing is absolutely BEAUTIFUL and you have NOTHING to even think about IF those are just little divots in the metal which I think they are from what I can see in the photos.

Really, BEAUTIFUL work there!

Brian
Wow, thanks. I didn't think the work I was doing was on the level you're describing. I still see things I'm not happy with and see room for improvement though.

In the pictures I posted none are going through the material completely, they're pretty much little craters or pits. Like you, I keep the heat and speed down on the initial tacks. My welder has voltage setting 1-4, I would have it on 1 for this. On the next pass, when I have some more material around to soak up the heat, I will turn the voltage setting to 2. I couldn't imagine turning it to 3 for sheet metal. I guess wire speed is the answer. Also these patches and the original metal I posted pics of measured out to be 20 gauge. Most of the other exterior sheet metal on the car that I've worked with has been thinner, and turning the voltage up to even 2 is risky business unless i want to blow holes.

Quote:
Originally Posted by mitmaks
Welcome to hotrodders.com, another Charger owner. When I was looking at pics I've immediately recognized Charger tail panel.
Are you a member on d-c.com yet?
As far as welding you're trying to be perfectionist. If those holes are not all the way through some spot putty would fill those in, or you can epoxy prime it and then 2K high build will cover imperfections like these.
Thanks, I'm not a member of that forum, but I recognize your avatar from my lurking over there. I'm a member of so many forums, they're hard to keep up with really. As far as being a perfectionist.....yeah maybe. But obviously something in my process is amiss and if I were doing it right I wouldn't even have this problem, so that's what I'm trying to figure out. Plus I've been waiting my whole life to restore this car; I can't short-change it after all this time.

Quote:
Originally Posted by MARTINSR
Look at this photo and you will see that your first welds are looking great, they have been ground down and really looking great. The second welds look like they were done at the same low heat setting and they didn't penetrate nearly as much as they should have. If you had the wire speed up a little (it is carrying the electrons, look at upping the speed as using a larger water hose) and the heat a little (look at the heat as the pressure behind the water in the hose) so you can make a faster, hotter weld that will flow more quickly into those first welds. It will provide a flatter weld, as the wire is going INTO that surrounding metal and not sitting on top.

But even the first welds could us a little more wire speed as you can see there is that divot in the middle where it didn't get all filled up before it solidified it collapsed.

We are talking just tiny adjustments. Do a long practice weld and mark it off with a Sharpie pen. Use a particular setting, weld a few inches, change the setting and weld a few inches more. Now, you want to skip around so this would be hard while you are changing settings but not impossible. You could also weld a few at one setting then work on something on the car then go back and put at little more at that setting before you move onto another setting.

One very important thing with any kind of practice, you need to do EVERYTHING exactly as you would on the real thing. Practicing basket ball with a ball that is low on pressure isn't going to help you a damn bit in the real game when the ball is harder. You need to do everything exactly the same including that fine prep you did. One more thing, if you get the gaps tighter you are better off as well. Lay your piece of metal on the area you are replacing and using a scribe, a sharp awl or scribe and mark the metal up tight with the new piece. Trim the old junk off right at that line and your new piece is going to fit tighter.

Brian
The second welds were done on voltage setting 2, the first pass were on 1. I will just have to practice more on some scraps and really get a grasp of things. It seems like if I turn the wire speed up too much it pushes the puddle through and I end up with a hole.

That is how I fit my patches though. BUT I notice I tend to make my gap a bit large in the name of adequate penetration. The picture you reposted of mine is the last time I touched the welder on that patch. After that I ground it down and the last two pics I posted are the end result of that. I didn't have to go back on the underside with the welder because of inadequate penetration, which was another problem I was having.

Quote:
Originally Posted by deadbodyman
Hey ,what about the wire itself??? old wire ??? surface rust on the spool of wire contaminating the weld???? or the gas itself being old ?When I took a welding coarse to get certified the teach told us that acetylene separates after a while and you have to lay the tank down and roll it to mix the gasses back up.I dont know if its true or if mig gas is different but I'm sure some of the real welders here would know...just a couple things to ponder..
The spool I'm using right now is only about a month old. There is air con in the garage so despite being East Texas and humid, it stays pretty dry in there. I don't know enough about welding to comment on your theory of having to mix up the gas, but I've got a recently filled tank hooked up.
06-18-2012 05:54 AM
deadbodyman Hey ,what about the wire itself??? old wire ??? surface rust on the spool of wire contaminating the weld???? or the gas itself being old ?When I took a welding coarse to get certified the teach told us that acetylene separates after a while and you have to lay the tank down and roll it to mix the gasses back up.I dont know if its true or if mig gas is different but I'm sure some of the real welders here would know...just a couple things to ponder..
06-12-2012 09:32 PM
John long Huhhhh ? Lol...........
06-12-2012 04:23 PM
deadbodyman I JB welded my reading glasses in my helmet. now I always know where they are...but I can only read when I'm welding...I better get some fire extinguishers in the office...
06-12-2012 08:41 AM
MARTINSR There would be no reason to use anything like JB weld. Too hard to work with, epoxy primer and a dab of polyester putty and it's done.

Brian
06-12-2012 08:36 AM
unclebill jb weld it and be done in 5 minutes
move on to next chore
06-12-2012 07:38 AM
MARTINSR This is true, I'll be getting me a couple, thanks.

Brian
06-12-2012 06:24 AM
Old Fool
Quote:
Originally Posted by MARTINSR
Wow, now all I need to do is figure out what magnification. Does it end up being about the same as the magnifying eye glass strength that works for the lens? Because I had a hell of a time picking out the glasses I have. There is a very wide range of powers and from one to the next they were very difficult to pick out.

Brian
Pick a power that your reading glasses are to start with.

I like to be up close and personal when I tig or mig so I went with one strength stronger .

The closer you get to what you are looking at the higher the diopter needs to be.

Hey @ $4 a piece for the cheater lens, you can try a couple strengths to see what you like.
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