Author Topic: Flux core vs mig (Read 44567 times)

junya92toy · « **Reply #90 on:** Mar 23, 2011, 09:17:28 PM »

Quote from: yjay on Mar 23, 2011, 09:15:19 PM

For certification of the production pipe welds or for qualification/certification of the welder/operator?

both actually, first you have to get the weld procedure approved, with a weld test, and then you have the welders take that test and they get certified.

yjay · « **Reply #91 on:** Mar 23, 2011, 09:24:11 PM »

Right, so the welding procedures and welders/operators are certified through destructive testing and the production welds are certified through non destructive testing right?

junya92toy · « **Reply #92 on:** Mar 23, 2011, 09:28:50 PM »

That is correct. That is first a visual, then it can be a ultrasonic test, a magflux test, x ray, electro test, dye penetrate test etc.

yjay · « **Reply #93 on:** Mar 23, 2011, 10:10:36 PM »

When you are welding beveled materials together at your job, you have empirical evidence through testing that your welds are sound and have no reject able defects in areas that are not visible to anyone but those that are testing them through non destructive methods. This would mean that if you weld something from one side only that you have shown through testing and experience that you are capable of depositing a full pen weld in this manner, and therefore making a superior assembly compared to a partial penetration or fillet weld. It's my contention that the average shade tree mechanic/non professional welder does not have the experience due to the fact that they don't weld for a living to gain a benefit from beveling everything that they weld. The statement was made that whenever possible bevel the edge. I don't agree with that personally. For instance, I see no benefit to beveling a tube crossmember that will be welded into a framerail (as a pertinent example for a truck building website). Without knowing what the hidden backside of that weld looks like, being done by the average person that may be building a project truck, I believe a fillet weld done with proper technique and proper machine settings that can pass simple visual inspections that can be pretty easily performed by the person doing the welding after a little online research is probably best.
Beveling is a necessary procedure in some instances, but to state that it is a benefit in all or even most circumstances to me incorrect. Simple fillet welds are the most common welds done in most applications dealt with here and do not benefit from bevels.

junya92toy · « **Reply #94 on:** Mar 23, 2011, 10:41:37 PM »

Its always good to bevel. It gives the weld a place to go, and it gets you more penetration. even in tube work, it would be better. Even if its not a 100% pen with a bevel but say you bevel with a land half the thickness of the metal its a plus. Even fillet welds its a plus, a fillet weld pretty much has no penetration at the root. So the strength comes from the weld re enforement its self, you remove the piece breaks. you weld with a bevel and re move the re enforcement, it wont as easily, if its a partial pen, full pen it wont.

I make a lot of frames for tables and such, with.065 wall and up tube, I always bevel the edge.
Now I will say this, I do a lot of fillet welds too on the thickness, and I dont bevel, because Im not removing the re enforcement.
The negitive side to bevel a fillet weld, it takes time. And is that extra strength need for a fillet weld, depends.Are fillet welds done without a bevel, all the time, is it fine yes.

The evidence that you are doing sound welds? Yes thats your weld cert test you took. Sometimes a inspector will even watch you weld, bead by bead.

I talk about all this, and how its done, because even though it might not be done on trucks here a lot, it is good to know if you need to weld something thick, or critical. Making bumpers and welding suspension work should be done with the best way you can.

yjay · « **Reply #95 on:** Mar 24, 2011, 08:54:48 PM »

I would not say it is always good to bevel. If someone who is not fairly well skilled in welding bevels a component that is say 10 ga. and will not be able to see the back side of that component to verify that there is no overlap, slag inclusions, etc. has a good chance of making a weld that would be less durable than one that was fillet welded and able to be fully observed and repaired as needed. I have no doubt that you are fully capable of achieving complete joint penetration in a non backed beveled edge, but you're a skilled craftsman. Most people weld on occasion and will probably do best with simpler fit up

. Your assemblies probably do benefit to a degree from bevels.
The majority of welds that are required to be full pen on structures that are governed by D1.1 are required to be non destructively tested even when performed by qualified welders iirc.
That's not to say that there aren't a lot of good welders who are completely capable of doing anything that would ever arise on a project truck, but full pen welds, especially out of position without backing are a bit of a specialized operation. The average amateur who only welds on occasion will have a much better likelihood of achieving what would be considered an acceptable fillet weld than they would of doing the same with a full pen. That's why a person who is qualified for full pen is also qualified for fillet, but not vise versa.

yjay · « **Reply #96 on:** Mar 24, 2011, 09:01:46 PM »

It would appear that the boring technical trend this thread has taken has caused everyone else to leave

junya92toy · « **Reply #97 on:** Mar 24, 2011, 09:08:50 PM »

Well if you compare bevel to non bevel welded, and ignore the human error. WHen both properly welded, the beveled joint will be stronger. Tech speaking, a part pen weld, at the root is a the start of a crack too

yjay · « **Reply #98 on:** Mar 24, 2011, 09:25:01 PM »

I agree to a point. The root of a partial penetration weld is a stress riser. A partial pen weld has basically the same strength values as a fillet weld with the same effective throat as the thickness of the base metal. I guess that's my point. A beveled edge that results in full penetration and no rejectable discontinuities on the opposing side is obviously a superior connection. But to expect that from the occasional welder is reaching a bit, so a fillet weld would probably be preferable in most cases for the amateur so the weld can be visually observed and verification can be better made as to whether the weld is sound.

Gear Jammin-Dog Chasin-Yota Man · « **Reply #99 on:** Mar 25, 2011, 07:04:28 AM »

That was my attempted point too

junya92toy · « **Reply #100 on:** Mar 25, 2011, 07:20:03 AM »

Quote from: junya92toy on Mar 24, 2011, 09:08:50 PM

Well if you compare bevel to non bevel welded, and ignore the human error. WHen both properly welded, the beveled joint will be stronger. Tech speaking, a part pen weld, at the root is a the start of a crack too

As a side thing, I was installing some railing on some steel stairs at a college and found this.

Burl · « **Reply #101 on:** Mar 25, 2011, 07:37:03 AM »

I said I wasn't interested anymore but back to one of my posts earlier, Beveling a T joint will allow the perpendicular piece to be penetrated well with the current settings on the welder, however the rest of the parent material is still at full thickness and less penetration will be achieved to the base plate and the full thickness piece just above the beveled area. A way to overcome this would be to pre-heat the base plate with a rose bud as for the perpendicular beveled piece pre-heating it would most likely cause the welder to blow through the beveled area. The better way to get even and equal penetration to both pieces of material would be to use an alternate form of welding like spray transfer. And how often is it going to be realistically possible to pre-heat any metal near most of the welding projects that the members of this board are attempting. If your going to try to convince audiences through proper debate you have to fully consider those you are trying to convince. Most of the non status quo info coming into this discussion is irrelevant to the non certified homeowner hobbyist.

Gear Jammin-Dog Chasin-Yota Man · « **Reply #102 on:** Mar 25, 2011, 07:43:02 AM »

junya92toy · « **Reply #103 on:** Mar 25, 2011, 07:48:13 AM »

Quote from: Burl on Mar 25, 2011, 07:37:03 AM

I said I wasn't interested anymore but back to one of my posts earlier, Beveling a T joint will allow the perpendicular piece to be penetrated well with the current settings on the welder, however the rest of the parent material is still at full thickness and less penetration will be achieved to the base plate and the full thickness piece just above the beveled area. A way to overcome this would be to pre-heat the base plate with a rose bud as for the perpendicular beveled piece pre-heating it would most likely cause the welder to blow through the beveled area. The better way to get even and equal penetration to both pieces of material would be to use an alternate form of welding like spray transfer. And how often is it going to be realistically possible to pre-heat any metal near most of the welding projects that the members of this board are attempting. If your going to try to convince audiences through proper debate you have to fully consider those you are trying to convince. Most of the non status quo info coming into this discussion is irrelevant to the non certified homeowner hobbyist.

Its all about fusion, look up friction welding, explosion welding, forge welding.
In a t joint if the piece with the edge is beveled and the weld is 100% pen, and is fused to the bottom plate. Its good. Thats penetration, because you have fusion on both pieces.

Burl · « **Reply #104 on:** Mar 25, 2011, 07:53:17 AM »

And restating and still not getting anywhere, fallacy of denying a valid conclusion.

junya92toy · « **Reply #105 on:** Mar 25, 2011, 08:09:05 AM »

Cuz you dont get it.

jimbo74 · « **Reply #106 on:** Mar 25, 2011, 08:10:14 AM »

jb weld is fine

Burl · « **Reply #107 on:** Mar 25, 2011, 08:33:04 AM »

Quote from: junya92toy on Mar 25, 2011, 08:09:05 AM

Cuz you dont get it.

I don't have to get it, and I don't have to persuade you, all the status quo defenders need to do, is to convince the rest or some of the members on this board of the status quo and the status quo will remain.

Dr.Maxwe001 · « **Reply #108 on:** Mar 25, 2011, 08:48:12 AM »

Burl junya92toy HAS MORE MAN HOURS WITH WELDING than prolly you and I put together LISTEN AND LEARN AND QUIT BEING SO STUBURN

Burl · « **Reply #109 on:** Mar 25, 2011, 09:39:42 AM »

Calling out your credentials as well, this isn't my first engine drive. The other one had a hobbs meter but I don't remember the hours. If my mig machines could tell time they'd say to my engine drive " I was over the hill be fore you were on the tit." Personal attacks don't help anyone's cause I wouldn't recommend continuing them. I fully support beveling and do when appropriate. But the audience needs catering. If you look closely there's a cameo

Sparkplug · « **Reply #110 on:** Mar 25, 2011, 09:53:17 AM »

I want a trailblazer, lucky b*std

Burl · « **Reply #111 on:** Mar 25, 2011, 10:14:06 AM »

Quote from: Sparkplug on Mar 25, 2011, 09:53:17 AM

I want a trailblazer, lucky b*std

I want one of these now http://www.millerwelds.com/products/enginedriven/product.php?model=M00186. It's probably gonna be my next upgrade.

IronClad · « **Reply #112 on:** Mar 25, 2011, 10:17:11 AM »

Quote from: Burl on Mar 25, 2011, 09:39:42 AM

Calling out your credentials as well, this isn't my first engine drive. The other one had a hobbs meter but I don't remember the hours. If my mig machines could tell time they'd say to my engine drive " I was over the hill be fore you were on the tit." Personal attacks don't help anyone's cause I wouldn't recommend continuing them. I fully support beveling and do when appropriate. But the audience needs catering. If you look closely there's a cameo

Dont mind max hes just another leg humper and doesnt belong in a welding thread.. he's been known to weld without a helmet and get severe flashburn more than once so he really shouldnt even be near a welder

Burl · « **Reply #113 on:** Mar 25, 2011, 10:32:51 AM »

copy that

Dr.Maxwe001 · « **Reply #114 on:** Mar 25, 2011, 01:44:44 PM »

Quote

Dont mind max hes just another leg humper and doesnt belong in a welding thread.. he's been known to weld without a helmet and get severe flashburn more than once so he really shouldnt even be near a welder

whats a helmet and what is this "FLASHBURN" you speak of I have a very good suntan and also wear sunglasses

yjay · « **Reply #115 on:** Mar 25, 2011, 05:52:04 PM »

I will be getting this at my work shop next week. Lincoln Power Mig 350MP. It's pretty sick. 350 amps, and will do stick which will be cool for carbon arc gouging, as well as pulsed arc mig. It is capable of GTAW as well, and push/pull wire feeding for aluminum and/or a longer hose because it can be equipped with a feed roller at the gun.
Not that it has any bearing on the discussion, but I'm stoked.
They told me to get what I wanted so this is definitely it.

junya92toy · « **Reply #116 on:** Mar 25, 2011, 06:10:36 PM »

Does that have the controls in the handle for different settings or programs? I thought I read somewhere you can get models with that

4RunnerChevy · « **Reply #117 on:** Mar 25, 2011, 06:19:53 PM »

Quote from: yjay on Mar 25, 2011, 05:52:04 PM

I will be getting this at my work shop next week. Lincoln Power Mig 350MP. It's pretty sick. 350 amps, and will do stick which will be cool for carbon arc gouging, as well as pulsed arc mig. It is capable of GTAW as well, and push/pull wire feeding for aluminum and/or a longer hose because it can be equipped with a feed roller at the gun.
Not that it has any bearing on the discussion, but I'm stoked.
They told me to get what I wanted so this is definitely it.

Bought one a couple months ago, very nice. You will be stoked. We ordered a spool gun, so I'll let you know how that works out.

yjay · « **Reply #118 on:** Mar 25, 2011, 06:36:18 PM »

No. The Miller unit I looked at for the same price had the controls in the handle and that's why I didn't get it. I have always preferred Miller over Lincoln, but I was concerned about the durability of that setup.
This sucker is so tech that it has a usb input so you can download new arc waveforms as they are available

It also has a toggle type input where you tell it what process, type of metal, wire diameter, etc. that you are using and it automatically sets your machine to preset settings for you. They are manually adjustable from there.
A quantum leap forward from the ancient Hobart I've been using. I think it came out just after electricity was discovered although it's still one of the best, most user friendly units I've used.
Gonna miss the old girl

..... Kinda.

yjay · « **Reply #119 on:** Mar 25, 2011, 06:41:11 PM »

Quote from: 4runnerchevy on Mar 25, 2011, 06:19:53 PM

Bought one a couple months ago, very nice. You will be stoked. We ordered a spool gun, so I'll let you know how that works out.

Sweet. Any reason you ordered a spool gun as opposed to the push/pull? Big price differece i suppose?

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