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Welding Flex#12
#1
Scott or someone need help!

I'm not a welder or pretend to be one but am determined to learn on my 72. Welding the cowl hat on and making repairs to the lower cowl.

When I shine a light on the top of the patch that was butt welded in (and the hat) I noticed pin holes along the but weld. Will the Flex #12 seal all these? Do I have to worry about completely sealing up with the weld? The metal is not liking the MIG. It blows holes through the existing metal and was beginning to become a problem. I finally got it where it looks half way decent but am concerned about the pin holes along the joint. I did try to eliminate every hole by re-welding and grinding again but the metal is starting to get sensitive to the heat. I'm using 18 gauge on the butt welded patches. I was tacking properly and not running beads to cut down on heat.

Chasing Rust
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#2
I assume you checked to make sure you have enough gas for the mig welder. That might be a reason for bad welds. Also if the rust has gone through completely it is very hard to do a good weld. If it looks pretty solid I don't think you will have to much trouble. Just make sure the pin holes are well sealed up with whatever prep you will do before painting. Or else the rust will just come right back.

Eric


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DRIVE IT DON'T STORE IT!
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#3
Darren 72;17564 Wrote:Scott or someone need help!

I'm not a welder or pretend to be one but am determined to learn on my 72. Welding the cowl hat on and making repairs to the lower cowl.

When I shine a light on the top of the patch that was butt welded in (and the hat) I noticed pin holes along the but weld. Will the Flex #12 seal all these? Do I have to worry about completely sealing up with the weld? The metal is not liking the MIG. It blows holes through the existing metal and was beginning to become a problem. I finally got it where it looks half way decent but am concerned about the pin holes along the joint. I did try to eliminate every hole by re-welding and grinding again but the metal is starting to get sensitive to the heat. I'm using 18 gauge on the butt welded patches. I was tacking properly and not running beads to cut down on heat.

D..run a bead of the flexo on the weld line AFTER YOU RUST BULLET..before you flexo over the rust bullet scratch the area with a red scuff pad..It will seal your small pinholes..If your blowing through the joint with the welder try taking a piece of copper(I use a piece of 3/4" copper pipe flattened) behind the joint to back it up as you weld..You may need 2 people 1 to hold the copper with a vise grip ..also try the lowest setting on the welder & reduce the wire speed some...faster speed requires more heat


LOVE OF BEAUTY IS TASTE..THE CREATION OF BEAUTY IS ART
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#4
Yes I agree with Scott, lower your heat and speed on the welder. Also use the copper backing. if it is blowing one peace more then the other it is because it is thinner metal (rusted and will not take the same heat) focus the weld on the better metal, make sure ALL rust is GONE!!!!!! before welding. Mig does not do well with rust at all it makes it much harder to weld. Do a pulse weld ( just one small shot at a time) Good question!!
Good luck and please let us know how you make out!!
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#5
If you have no copper aluminum will work just as well.

Eric


[Image: a58hgh.jpg]
DRIVE IT DON'T STORE IT!
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#6
72fastback;17589 Wrote:If you have no copper aluminum will work just as well.

Yep! just clean it first.
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#7
What rust does is aislate the metal sheet.. that´s why your MIG does not do a good job... It can also happen that the MIG ground is not propperly linked to the car...

I´m not a professional on MIG either but i use it a lot... Very important is to take time to propperly set it up for the job you´re about to do... Me for example, i have a big MIG, very powerful because i weld tools we broke on the factory and stuff... my MIG welds better on 1/4" thick metal than on every thinner one... in fact, i cannot weld in less than 1/22" metal sheets...

When I do a weld on the car, I always go to the minimun power, average gas (i use MIG20 gas mixture) and a medium speed to start...I prectice how it welds outside the car in any piece of metal that is going to the trash anyway... I move the power and the speed untill the weld sounds... actual sound good... It doesn´t have to "spit".. the weld have to be clean and shinny... If you turn your welded piece upside down you have to see some heat burn arround the welded surface but no holes of that burn..

It´s at least, my way to go when i´m welding... Be aware that rust tend to make the metal thinner and that can cause holes too... The ideal is to weld with virgin metal... welding where rust has never acted...

Hope it helps!



Damián Cool

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#8
72fastback;17565 Wrote:I assume you checked to make sure you have enough gas for the mig welder. That might be a reason for bad welds. Also if the rust has gone through completely it is very hard to do a good weld. If it looks pretty solid I don't think you will have to much trouble. Just make sure the pin holes are well sealed up with whatever prep you will do before painting. Or else the rust will just come right back.

Thanks. The gas was full. Running between 20 and 30 cfh
Qcode351mach;17572 Wrote:
Darren 72;17564 Wrote:Scott or someone need help!

I'm not a welder or pretend to be one but am determined to learn on my 72. Welding the cowl hat on and making repairs to the lower cowl.

When I shine a light on the top of the patch that was butt welded in (and the hat) I noticed pin holes along the but weld. Will the Flex #12 seal all these? Do I have to worry about completely sealing up with the weld? The metal is not liking the MIG. It blows holes through the existing metal and was beginning to become a problem. I finally got it where it looks half way decent but am concerned about the pin holes along the joint. I did try to eliminate every hole by re-welding and grinding again but the metal is starting to get sensitive to the heat. I'm using 18 gauge on the butt welded patches. I was tacking properly and not running beads to cut down on heat.

D..run a bead of the flexo on the weld line AFTER YOU RUST BULLET..before you flexo over the rust bullet scratch the area with a red scuff pad..It will seal your small pinholes..If your blowing through the joint with the welder try taking a piece of copper(I use a piece of 3/4" copper pipe flattened) behind the joint to back it up as you weld..You may need 2 people 1 to hold the copper with a vise grip ..also try the lowest setting on the welder & reduce the wire speed some...faster speed requires more heat

Thanks Scott...I was running at the A setting on the welder. I will back the speed down. I was running around 3 on the speed. I have one of those Home Depot Lincoln welders.
docweld;17574 Wrote:Yes I agree with Scott, lower your heat and speed on the welder. Also use the copper backing. if it is blowing one peace more then the other it is because it is thinner metal (rusted and will not take the same heat) focus the weld on the better metal, make sure ALL rust is GONE!!!!!! before welding. Mig does not do well with rust at all it makes it much harder to weld. Do a pulse weld ( just one small shot at a time) Good question!!
Good luck and please let us know how you make out!!

Thanks for the concerns and help. I'm learning on this beast. Tough metal to be learning on. It's so thin. I have been heating up weld on the new matal patch and trying to carry over the tack to the old metal. I'm not sure why there so many pin holes. Maybe I'm not getting the tacks close enough. IT looks good before I grind. It seems like the welds are not getting into the seams and I'm grinding the surface off exposing the seams again. If I try to get into the seam directly, I am scared it's going to blow through the metal again. Every time I do it again there is even less metal due to grinding.

When you weld a patch in, should there be no holes at all or is it common and thats why they make a sealer? My biggest fear is after all this struggle and time the things going to leak. I'm going to take Scott's advice and do 2 coats of rust bullet, then the flex 12, and finally the rust bullet black shell. Probably 2 coats of that also. I'm hoping everything will seal with all this.
URUGUAYAN_FASTBACK;17663 Wrote:What rust does is aislate the metal sheet.. that´s why your MIG does not do a good job... It can also happen that the MIG ground is not propperly linked to the car...

I´m not a professional on MIG either but i use it a lot... Very important is to take time to propperly set it up for the job you´re about to do... Me for example, i have a big MIG, very powerful because i weld tools we broke on the factory and stuff... my MIG welds better on 1/4" thick metal than on every thinner one... in fact, i cannot weld in less than 1/22" metal sheets...

When I do a weld on the car, I always go to the minimun power, average gas (i use MIG20 gas mixture) and a medium speed to start...I prectice how it welds outside the car in any piece of metal that is going to the trash anyway... I move the power and the speed untill the weld sounds... actual sound good... It doesn´t have to "spit".. the weld have to be clean and shinny... If you turn your welded piece upside down you have to see some heat burn arround the welded surface but no holes of that burn..

It´s at least, my way to go when i´m welding... Be aware that rust tend to make the metal thinner and that can cause holes too... The ideal is to weld with virgin metal... welding where rust has never acted...

Hope it helps!
Thanks..Appreciate the advice. Every bit helps. I'm not that good when it comes time to calibrate the speed and heat before welding. I couldn't weld on the B setting on my welder so I went to the A. That was a no brainer. B setting was blowing through everything. The speed I changed but never got a good feeling about what was right or wrong. I am running it on 3 and may try to turn it down. If the weld is spitting back what does it mean? I'm sure it's a clue of what I should do concerning the settings but I'm ignorant to the fact.

The car came apart so quickly but now everything is proceeding at a snail's pace. My car buddies want my car back on the road this summer and they are putting pressure on me to get it done..lol. Not sure if I can get it back together before the summer. I'm getting impatient and constantly remind myself that I have to slow down and be patient. I don't really have much help. It's hard when you need a second set of hands. Thank God for this forum and all the guys that are willing to help out!

Chasing Rust
  Reply
#9
[/quote]
Thanks..Appreciate the advice. Every bit helps. I'm not that good when it comes time to calibrate the speed and heat before welding. I couldn't weld on the B setting on my welder so I went to the A. That was a no brainer. B setting was blowing through everything. The speed I changed but never got a good feeling about what was right or wrong. I am running it on 3 and may try to turn it down. If the weld is spitting back what does it mean? I'm sure it's a clue of what I should do concerning the settings but I'm ignorant to the fact.

The car came apart so quickly but now everything is proceeding at a snail's pace. My car buddies want my car back on the road this summer and they are putting pressure on me to get it done..lol. Not sure if I can get it back together before the summer. I'm getting impatient and constantly remind myself that I have to slow down and be patient. I don't really have much help. It's hard when you need a second set of hands. Thank God for this forum and all the guys that are willing to help out!

[/quote]
D..I think your running too much gas ...should be between 12-15..I never look at the gas or speed setting only heat ONCE I'm dialed in..The best way I have found is to do it by ear & sight..Start at 12 on the gas..low on the heat..grab a piece of scrap metal..Lay a bead & as your welding turn the speed up or down till it sounds like bacon frying..Get close then do the same thing with gas...Works for me..Also are you laying the tip of the welder at a slight angle ? If not you should be...Also your ground should be as close as possible to where your welding....025 wire size(wire size will make a huge difference!!! thicker wire=more heat) & nozzle gel before every welding session...try the above


LOVE OF BEAUTY IS TASTE..THE CREATION OF BEAUTY IS ART
  Reply
#10
Thanks..Appreciate the advice. Every bit helps. I'm not that good when it comes time to calibrate the speed and heat before welding. I couldn't weld on the B setting on my welder so I went to the A. That was a no brainer. B setting was blowing through everything. The speed I changed but never got a good feeling about what was right or wrong. I am running it on 3 and may try to turn it down. If the weld is spitting back what does it mean? I'm sure it's a clue of what I should do concerning the settings but I'm ignorant to the fact.

The car came apart so quickly but now everything is proceeding at a snail's pace. My car buddies want my car back on the road this summer and they are putting pressure on me to get it done..lol. Not sure if I can get it back together before the summer. I'm getting impatient and constantly remind myself that I have to slow down and be patient. I don't really have much help. It's hard when you need a second set of hands. Thank God for this forum and all the guys that are willing to help out!

[/quote]
D..I think your running too much gas ...should be between 12-15..I never look at the gas or speed setting only heat ONCE I'm dialed in..The best way I have found is to do it by ear & sight..Start at 12 on the gas..low on the heat..grab a piece of scrap metal..Lay a bead & as your welding turn the speed up or down till it sounds like bacon frying..Get close then do the same thing with gas...Works for me..Also are you laying the tip of the welder at a slight angle ? If not you should be...Also your ground should be as close as possible to where your welding....025 wire size(wire size will make a huge difference!!! thicker wire=more heat) & nozzle gel before every welding session...try the above


[/quote]

SCott,

That's the exact question I asked the local restoration car shop in the area. They said the .030 or .035 was fine. I thought the same thing about the wire. I am going to change it out and see what the difference is. On the gas it is 12 cfh or 12 l/min. I am using the cfh at about 25 which is approx 12 l/min.

You got me on nozzle gel?

I am setting on lowest speed and running a bead w/o gas? When it sounds like bacon frying I then do it again with gas on maybe around 12?

Where does the speed come in on this test. You mentioned before that I should turn down the speed. I have been running around 3. I was going to try and run it lower. If I change wire everything I have been doing may change so I guess the speed may change and I may be fine where it is.

Thanks Scott. I probably owe you a few beers at this point. Thanks again.

Chasing Rust
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