tig and sfi specs

do tig welds need to be convex to pass tech?
I have been getting some nice looking welds and have had them looked at by welders at work.
I have been making tight fitting joints, but am having trouble staying uniform with my filler rod. they look nice, but are slightly flat or concaved.
I get a small convex with filler, but they arent uniform in appearence.
Thanks for any input.
any good videos out there?

A Tig weld puddle surface that looks either convex or concave should be fine depending on the type of weld joint (such as inside corner, flat, outside corner). What you don't want to see is an under cut edge looking puddle.

Striving for a good fitting joint is something to shoot for. But remember that what makes a "good" joint fit isn't the same for all materials & thicknesses. A super tight fitting joint on say 1" x .058" cm tubing is most definitely the way to go. But the same super tight joint on a piece of say 1.625" x .134" ms is really too tight and can cause problems.

Remember just because it's a Tig welder doesn't mean it doesn't sometimes need some penetration "help" from either a looser fitting joint, or a beveled edge to that joint.

Also don't get all caught up in the "make the Tig puddle as small as possible" thinking. The truth is that the "correct" puddle size is usually directly related to both the joint design & the thickness of both parent materials. A super tiny weld puddle on a tight joint with a piece of .049" thick cm wing strut material might be fine. But the same size weld puddle on a tight joint done on a 1.625" x .083" cm tube is asking for trouble.

And along this same thinking the opposite would also be true. A big puddle on a loose joint using the thin .049" thick material will most likely result in an over heated weld joint.....that is if it doesn't flat out torch a hole in it trying to fill it.

thanks for the info. it will be mostly 1.625 x .134 on my truck. unless i switch to moly. as of now, its m/s
planned on beveling. will practice some more tuesday and maybe post a pic.

Dave Maxwell wrote:will practice some more tuesday and maybe post a pic.

That's one of the most important things you can do, just practice & practice some more. Learn what parameters work best for you for any given tube OD & thickness (tungsten size, filler rod size, amp range vs pedal range vs joint fit, etc, etc).



Some other tips.......

If you are able, place your tack welds where you plan any given weld pass to end. This way it's easier to melt the tack into the puddle as the base material & filler rod are already up to "temp" by then & aren't cold as they would be if you were starting a weld pass on/near a tack weld. Placing the tack at the end of the pass also lessens the chance you will have to make an abrupt stop to welding if your unintentionally over heating the end of the pass. This is because the tack will act as a heat sink allowing you more gradually stop at the end of the pass as you melt the tack in. This technique is even more useful with Mig welding since starting on top of a tack is the last thing you want to do when using a Mig. This is because of Mig's colder "start" vs Tig.

If you happen to fit/grind a weld joint a little too loose in a spot or two, this is also a perfect place for a tack weld. The tack will act as additional filler material filling the gap & helping to keep the weld puddle temp from spiking as much as you run over it and slow down & spend extra time (and generate more heat) filling it.

Drill a small hole in the general area of the weld joint (3" to 5" away) to relieve internal air pressure build up from the weld heat. This will help prevent a puddle blow-out that can screw up the pass.

thanks again, that is some more great info.
I bought the syncro 200 from miller a week ago last thursday and have been practicing whenever i can.
It came with 3/32 tung and number 7 cup.
I went an purchased some 1/16 tung and number 6 cup as per there recommendations for sheet metal work.
been cutting strips of sheet an practicing on the thin stuff also.
i seem to have better luck with the thin. been using .035 mig wire for filler.
going to head out to shop in a little and practice your ideas also.

Thanks again for the help. I wish i lived close to someone that wouldnt mind making a few bucks teaching

Dave always has good info I like to set up 10amps for ever .010 but it can go up or down.

Dave Maxwell wrote:but they arent uniform in appearence.

Got to thinking about that and while perfectly uniform Tig puddle widths & stack lengths is something to shoot for, realistically only a select few people can pull it off 100% of the time. And even then it's usually bench welding that makes it possible where your sitting comfortable & relaxed while welding. Uniform puddles become harder to achieve as welding position/welder comfort gets worse (welding on the car while in/on/under/upside down). So don't be too hard on yourself if your weld puddle isn't 100% uniform........getting good weld penetration is more important than "looks". When you start practicing on thicker stuff like tubing you might think about chopping up a few of the finish weld joints & see how much weld penetration your getting.

About the most uniform weld puddles I have ever seen were on older Don Ness cars & welds I saw David Wolfe do in the past. Both were amazingly uniform like a perfect over lapping stack of dimes.


On the other hand my welds do vary a bit in width & at times can be larger/wider than what some people might consider "desirable" (especially on thicker ms).

I usually use a .0625" (1/16") 2% Tungsten & a #4 cup on most everything ms & cm up to about .134" thick. And the .09375" (3/32") tungsten on .1875" thick & thicker material, (or where I have to use a bigger OD filler rod than normal).

thanks again Dave,
What size filler rods do you use?
I used my 1/16 tungsten up to around 90 amps, then switched to 3/32 as per weld book i read. i will try the 1/16 higher. it is red band if i remember right. my 3/32 is orange.
the smaller cup size. besides tighter areas, what does it do?
I am a complete newbie at this. first time welding as a youngin was oxy/accet. did notice some similarity with the tig.
trying to expand my options is why i got a tig.
any good videos or books you recomend. Thought about taking a welding class.
i got some pieces fish mouthed i am going to play with friday i hope. havent been to shop since saturday, and its in my back yard.
hopefully tonight will actually sleep and can get up before work and do something.
captain morgan do your job

Dave Maxwell wrote:What size filler rods do you use?

For tack welding I use a .045" filler rod most of the time on cm & ms. But I have on occasion also used .035" Mig wire for tacking really, really thin stuff. For the actual weld pass probably 90% of the time it's either .045" or .0625" OD steel filler rod for both cm & ms.

Dave Maxwell wrote:the smaller cup size. besides tighter areas, what does it do?

That really is the main reason for a small #4 cup, getting into steep angle inside corners. But even with the small #4 cup you will find sometimes some joint designs will still require you to extend the Tungsten out far enough to possibly hurt gas coverage. In this situation you must make sure your not welding in a breeze. Close shop doors if you have too & turn off fans. Clamping a piece of card board or sheet metal to the back side of the a steep angle joint can help to trap more of the argon & help keep air away from the extended Tungsten & weld puddle.

Dave Maxwell wrote:any good videos or books you recomend.

Don't really know of any videos, I just learned with a bunch of practice.

Should also mention that if you need glasses to read small print, you probably also need glasses to Tig ms & cm since a small(ish) puddle is the norm. When I first started learning to Tig, at first I didn't realize I was actually having problems seeing what was going on. I could see the bulk of the puddle form, but I couldn't see down into the arc at the puddle's leading edge. Cheap drug store reading glasses made a night & day difference in my ability to see what was going on as the puddle formed & my Tig welds looked 100% better after I started using them.

Dave my Stepson use to work for Ness for about the last 12 years.... he is a damn fine welder. and now works for a ProStock team.......


Randy

www.weldingtipsandtricks.com

for tech and videos

yes i have noticed lately that things up close are hard to focus on. pushing 40 does that i guess. i will try those walgreen specs.
been to the weldingtips sight. it is very good. cant get the vids to play though

sorry the vidoes dont work ya, i have the slowest internet you can get and they worked for me,just slow loading tho. i have to use the cheap reading glass to read and see this dam computor, tomarrow im going to use them welding and see how much better i can well.

the Coug wrote:Dave my Stepson use to work for Ness for about the last 12 years.... he is a damn fine welder.

That was probably a great learning experience for him.

I may be wrong but I'm pretty sure that Ness can be credited with being the "father" of the modern door car cage layout behind the main hoop. Before most all the P/S cars had the same basic old style rear 4 bar layout supporting the main hoop, two bars straight back & two bars forming the "X" (like Don Hardy and Alston). But Ness's design of looping a bar up over the top of the tubs allowed more attachment points for more diagonals. That really made things a lot more rigid back there, and allowed the main frame rails to be hung higher in the car for more tire room and a lower body stance.

If Ness wasn't the first guy who did the cage this way back then, he was at least one of the first.

DILLIGASDAVE wrote:

Dave Maxwell wrote:will practice some more tuesday and maybe post a pic.

That's one of the most important things you can do, just practice & practice some more. Learn what parameters work best for you for any given tube OD & thickness (tungsten size, filler rod size, amp range vs pedal range vs joint fit, etc, etc).



Some other tips.......

If you are able, place your tack welds where you plan any given weld pass to end. This way it's easier to melt the tack into the puddle as the base material & filler rod are already up to "temp" by then & aren't cold as they would be if you were starting a weld pass on/near a tack weld. Placing the tack at the end of the pass also lessens the chance you will have to make an abrupt stop to welding if your unintentionally over heating the end of the pass. This is because the tack will act as a heat sink allowing you more gradually stop at the end of the pass as you melt the tack in. This technique is even more useful with Mig welding since starting on top of a tack is the last thing you want to do when using a Mig. This is because of Mig's colder "start" vs Tig.

If you happen to fit/grind a weld joint a little too loose in a spot or two, this is also a perfect place for a tack weld. The tack will act as additional filler material filling the gap & helping to keep the weld puddle temp from spiking as much as you run over it and slow down & spend extra time (and generate more heat) filling it.

Drill a small hole in the general area of the weld joint (3" to 5" away) to relieve internal air pressure build up from the weld heat. This will help prevent a puddle blow-out that can screw up the pass.

Dave, I would like to say thanks for your willingness to give info... no matter where you are.

Dave Maxwell wrote:thanks again, that is some more great info.
I bought the syncro 200 from miller a week ago last thursday and have been practicing whenever i can.
It came with 3/32 tung and number 7 cup.
I went an purchased some 1/16 tung and number 6 cup as per there recommendations for sheet metal work.
been cutting strips of sheet an practicing on the thin stuff also.
i seem to have better luck with the thin. been using .035 mig wire for filler.
going to head out to shop in a little and practice your ideas also.

Thanks again for the help. I wish i lived close to someone that wouldnt mind making a few bucks teaching

Hello go to the local welding shop & buy some .049&1/16 & 3/32 TIG welding rod (probably E70(s) ) for your need & type of metal you are welding!! Concave (shallow) welds are NOT filled (not a bad thing) A beginner (YOU now!!! ME at one time) has trouble in NOT feeding enough metal (filler wire) Try a larger wire & see if that helps!!! To large of wire is also BAD!!!! TRY DIFFERENT THINGS & SIZES!!! Where do you live ??? I will go a long way for a FREE lunch!!! ( I ride all over the country on my motorcycle!!!LOL) PM if you have any questions!!!..I am a (high pressure) welder by trade!! Wleding shops also sell "cheaters" a magnifieing lense for welding hoods!!! chuck

Hey Dave, how has the Tig practice gone? Have you moved on to tubing yet?

practice is going great. havent messed with the tube much. been so busy with sheet metal work. i took the ford script from my tailgate. it used to be recessed a couple inches. i moved it out to the same plain as the tail lights now. it follows the bed lines better. not that it will be easily seen with a chute and wing. but it was something i wanted.
i only work on it from 8am till 11. then i have to go to bed to be up by 4 to see wife and kids.
progress is slow, but its progress.
wont see first shift for a few years.

have a good one,
Dave

been welding round spacers to flst stock alot lately. Something I have unlimited supply of. The flat side looks good, but I keep getting an undercut on the tube. I guess that's what you call it. I'm melting a groove in the tube. If I could post pics from my phone I would. I can email them. Thanks again everyone