1966 Valiant for the Other Daughter....
- Thread starter JimKueneman
- Start date
JimKueneman
Mopar Nut
Needs hinges rebuilt and adjusted first
MJM
Promoted Users
I see a shrinking disk in someone's near future. Personally I would have fitted the door to it's best possible position. Then use it as a guide when welding in the 1/4 panel.
Speaking out my you know what again but, here goes nothing......
I know the weld will shrink the metal at the weld spot, so if there is a low, there has to be a high. If the welds didn't get planished enough, top and bottom of the 1/4 panel, I could see the welding raising the center of the panel.
If a shrinking disk won't fix it, you may have to slice a slit in the high spot, hammer and dolly the shape back, then weld up the slit.
Patiently waiting for Robert to tell me I'm way off base. I can handle the truth so my feelings won't get hurt.
Speaking out my you know what again but, here goes nothing......
I know the weld will shrink the metal at the weld spot, so if there is a low, there has to be a high. If the welds didn't get planished enough, top and bottom of the 1/4 panel, I could see the welding raising the center of the panel.
If a shrinking disk won't fix it, you may have to slice a slit in the high spot, hammer and dolly the shape back, then weld up the slit.
Patiently waiting for Robert to tell me I'm way off base. I can handle the truth so my feelings won't get hurt.
MP&C
Member
Way off base... 
The quarter was installed using a vertical seam at the B pillar. This "result" is exactly why I suggested to leave a flange on the front edge of the quarter earlier, as spot welds are nearly a distortion free install. But alas, without flanges is how the quarters arrived.
Any vertical seam is going to shrink and pull inwards given an outward crowned panel and the absence of planishing that weld to remove the effects of shrinking.. If this were in the center of the panel we would expect it to pull into a valley (many of you have seen this) as the cross section shaped like an "arc" is shrinking; it loses length from shrinking, it also pulls into a flatter arc. Hence the valley effect. Many people will see this abundance of movement as a stretch; I can assure you it is the wrong conclusion. As Jim placed this seam close to the front flange, this helps control the shrinking effects, but they are still there. On the opposite side, we have a wide open panel that outside the heat effects is attempting to remain the same flat-ish slight crown as it was pre-weld. At the weld, the panel is shrinking. The band between these two areas is being conflicted as what to do, one side shrinking the other not.. It is here, most often dead center of the crown, that you get a pucker as these two differing forces fight it out. The pucker you see is approx 2-3" to the left of the weld. Which means it was a side effect of the weld.
The correct method of repair is to fix the cause (shrinking of the weld), not the effect (pucker). Meaning, the weld shrunk and caused this, you will NEVER totally fix a shrink with more shrink. The lingering effects/stresses of the pucker will not go away until the weld is no longer pulling at the adjacent area. An attempted repair using a slice and weld is going to introduce more heat, shrinking, and pulling at the adjacent panels for a crap shoot of a repair. The present vertical weld needs to be planished (hammer and dolly) to fix the cause. As soon as he starts planishing efforts you will be able to see the pucker start to pull inward as the pulling/shrinking stresses are relieved.
The quarter was installed using a vertical seam at the B pillar. This "result" is exactly why I suggested to leave a flange on the front edge of the quarter earlier, as spot welds are nearly a distortion free install. But alas, without flanges is how the quarters arrived.
Any vertical seam is going to shrink and pull inwards given an outward crowned panel and the absence of planishing that weld to remove the effects of shrinking.. If this were in the center of the panel we would expect it to pull into a valley (many of you have seen this) as the cross section shaped like an "arc" is shrinking; it loses length from shrinking, it also pulls into a flatter arc. Hence the valley effect. Many people will see this abundance of movement as a stretch; I can assure you it is the wrong conclusion. As Jim placed this seam close to the front flange, this helps control the shrinking effects, but they are still there. On the opposite side, we have a wide open panel that outside the heat effects is attempting to remain the same flat-ish slight crown as it was pre-weld. At the weld, the panel is shrinking. The band between these two areas is being conflicted as what to do, one side shrinking the other not.. It is here, most often dead center of the crown, that you get a pucker as these two differing forces fight it out. The pucker you see is approx 2-3" to the left of the weld. Which means it was a side effect of the weld.
The correct method of repair is to fix the cause (shrinking of the weld), not the effect (pucker). Meaning, the weld shrunk and caused this, you will NEVER totally fix a shrink with more shrink. The lingering effects/stresses of the pucker will not go away until the weld is no longer pulling at the adjacent area. An attempted repair using a slice and weld is going to introduce more heat, shrinking, and pulling at the adjacent panels for a crap shoot of a repair. The present vertical weld needs to be planished (hammer and dolly) to fix the cause. As soon as he starts planishing efforts you will be able to see the pucker start to pull inward as the pulling/shrinking stresses are relieved.
123pugsy
Member
What Robert said for sure.
Here's something similar where I fixed the edge of a fender recently. I could not stretch it, so drastic shrinking had to be introduced. These pics are not for the feint of heart. Look at your own risk.
Same thing happens welding door edges for gaps. Only to me though because every other person online does it without their panels being totally screwed up.
Here's something similar where I fixed the edge of a fender recently. I could not stretch it, so drastic shrinking had to be introduced. These pics are not for the feint of heart. Look at your own risk.
Same thing happens welding door edges for gaps. Only to me though because every other person online does it without their panels being totally screwed up.
MJM
Promoted Users
Way off base...
The quarter was installed using a vertical seam at the B pillar. This "result" is exactly why I suggested to leave a flange on the front edge of the quarter earlier, as spot welds are nearly a distortion free install. But alas, without flanges is how the quarters arrived.
Any vertical seam is going to shrink and pull inwards given an outward crowned panel and the absence of planishing that weld to remove the effects of shrinking.. If this were in the center of the panel we would expect it to pull into a valley (many of you have seen this) as the cross section shaped like an "arc" is shrinking; it loses length from shrinking, it also pulls into a flatter arc. Hence the valley effect. Many people will see this abundance of movement as a stretch; I can assure you it is the wrong conclusion. As Jim placed this seam close to the front flange, this helps control the shrinking effects, but they are still there. On the opposite side, we have a wide open panel that outside the heat effects is attempting to remain the same flat-ish slight crown as it was pre-weld. At the weld, the panel is shrinking. The band between these two areas is being conflicted as what to do, one side shrinking the other not.. It is here, most often dead center of the crown, that you get a pucker as these two differing forces fight it out. The pucker you see is approx 2-3" to the left of the weld. Which means it was a side effect of the weld.
The correct method of repair is to fix the cause (shrinking of the weld), not the effect (pucker). Meaning, the weld shrunk and caused this, you will NEVER totally fix a shrink with more shrink. The lingering effects/stresses of the pucker will not go away until the weld is no longer pulling at the adjacent area. An attempted repair using a slice and weld is going to introduce more heat, shrinking, and pulling at the adjacent panels for a crap shoot of a repair. The present vertical weld needs to be planished (hammer and dolly) to fix the cause. As soon as he starts planishing efforts you will be able to see the pucker start to pull inward as the pulling/shrinking stresses are relieved.
Well how do you like that. I was right about being wrong, lol. Great explanation by the way.
Let me ask this....... is it easier to planish a weld that is warm, or cold? Does it matter when you planish the weld?
MP&C
Member
My thoughts are let it cool naturally so the shrinking has done what it's gonna do and planish as needed.
More importantly, it depends largely on process used. For MIG, which is going to give harder welds, I would planish while weld dots are by their lonesome, as they are more isolated and more readily planished. The tack, planish, grind, repeat that I've spoken of elsewhere here on the site. For any process, the most shrinking/distortion is introduced with starts and stops. MIG is what it is, you almost need to do singular tacks with the weld set hot in order to get full penetration welds. With TIG or O/A torch, the longer, more uninterrupted the weld is, the better. So with these I would wait until the welding is done and file/planish afterward..
Thats interesting, I guess we all have our way of doing things, how do you weld door edges to build them up.
123pugsy
Member
I use TIG. Steel rod. I tried silicon bronze to keep cooler and speed it up and the door reacted the same as that fender repair I showed.
BTW, that was a quickie repair and paint job on my El Camino over last winter. It had so many other collision dents and poor repairs that I just had it and got it done for cruising season. All rust was removed though. A bit of filler does not bother me in the least.
123pugsy
Member
That "rise" in the quarter panel could also be caused by too much material at the weld seam. A gap above and below the area and then the two panels touching tightly at the area could cause the bulge.
If there was a gap between the panels then of course this couldn't occur.
I was just out in the garage tacking up my roof panels and I had the same bulge. I took my Dremel and sliced it along the seam and it came down nicely.
If there was a gap between the panels then of course this couldn't occur.
I was just out in the garage tacking up my roof panels and I had the same bulge. I took my Dremel and sliced it along the seam and it came down nicely.
JimKueneman
Mopar Nut
@MP&C, how much planashing should I need to do before I start seeing some results? Now it is on the rotisserie I can actually reach up in there with the dolly. I was able to really get good solid blows all up and down that weld. Probably spent 5 minutes going up and down it with very very solid impacts on the weld and I am not really seeing any movement at all.
MP&C
Member
As stated above, the MIG produces a harder weld and I've found it easier to planish the singular weld dots, then grind flush. The grinding step both gets the panel thickness at the weld line back to original metal thickness (for consistency in what you've set your welder for, a weld can be up to 4-5 times the thickness of the parent metal which I'd contend affects weld penetration) and also to get the last set of weld dots out of the way for planishing the next set. Once you have a full weld bead with no planishing having taken place, you have weld dots that have been heated and cooled multiple times, and the bulk of the weld that makes things more of a challenge than one weld dot at a time.
If you don't see much for results in what you've planished, I would say to strike a bit harder on the next passes. Yes, plural. This is not a one and done. I would check your effectiveness by closely monitoring the pucker to see when it starts to become smaller. So yes, read between the lines. A profile template works wonders to see exactly what is going on. If you haven't made one, how do you know what your progress is?
At this point, I don't see any harm in sharing, as it's likely going to reach that point.
If you don't see much for results in what you've planished, I would say to strike a bit harder on the next passes. Yes, plural. This is not a one and done. I would check your effectiveness by closely monitoring the pucker to see when it starts to become smaller. So yes, read between the lines. A profile template works wonders to see exactly what is going on. If you haven't made one, how do you know what your progress is?
At this point, I don't see any harm in sharing, as it's likely going to reach that point.
MJM
Promoted Users
How did you shrink that panel, with a torch and damp rag?
MJM
Promoted Users
Thank you, Robert. I have a much clearer understanding of the process / procedure now. Going to pick up a damaged fender at the junk yard to cut up and make repair patches using mig and tig welds. Was going to buy a dedicated mig welder but, after researching welders, I will be going with a combination mig/tig/stick welder that has preset voltage/wire speed, as well as letting the user manually set voltage/wire speed. This type of welder fits within my budget vs individual welders.
Thanks again,
Mike
MJM
Promoted Users
"At this point, I don't see any harm in sharing, as it's likely going to reach that point"
Yes please share, open discussion is not argumentative. It's food for thought.
I'll assume this is OK with Jim.
I know some guys like to add material on the door edge by welding a rod on. I have never done it that way so I can't say what the effect of it would be, but since Pugsy said he always has trouble with the process, I thought I would offer a suggestion, its not a tip because I don't really know if its better or not.
All I know is that I've found that doing it by dots with a mig directly on the edge, will shrink the metal, but it just shrinks back away from the edge a short distance which will cause a bulge. We all know that it's the weld area that shrinks, but in this case the weld area will end up higher than before, even though the metal draws back from the edge.
So the shrinkage effect is to draw back from the edge, causing the bulge, and there is little to no low area. I think the curvature of the door--top to bottom--is what controls the distortion. After it cools, I use a stud gun to easily and precisely shrink the bulge, it might be the only time shrinking does fix welding distortion. Never tried building up the edge of a fender, so not sure what the effect would be there.
I know this works as described because the first time I did this was on the Nomad which already had the door straight from front to rear with only a slight natural type curve in it, so the welding affect on the door was easy to judge, even though that first attempt was rather sloppily applied and needed lead to finish it off. I first started out decades ago welding with a torch, and later with a tig welder, so I'm not an experienced mig welder, I just use it when low heat input is necessary.
I know some guys like to add material on the door edge by welding a rod on. I have never done it that way so I can't say what the effect of it would be, but since Pugsy said he always has trouble with the process, I thought I would offer a suggestion, its not a tip because I don't really know if its better or not.
All I know is that I've found that doing it by dots with a mig directly on the edge, will shrink the metal, but it just shrinks back away from the edge a short distance which will cause a bulge. We all know that it's the weld area that shrinks, but in this case the weld area will end up higher than before, even though the metal draws back from the edge.
So the shrinkage effect is to draw back from the edge, causing the bulge, and there is little to no low area. I think the curvature of the door--top to bottom--is what controls the distortion. After it cools, I use a stud gun to easily and precisely shrink the bulge, it might be the only time shrinking does fix welding distortion.
Never tried building up the edge of a fender, so not sure what the effect would be there.I know this works as described because the first time I did this was on the Nomad which already had the door straight from front to rear with only a slight natural type curve in it, so the welding affect on the door was easy to judge, even though that first attempt was rather sloppily applied and needed lead to finish it off. I first started out decades ago welding with a torch, and later with a tig welder, so I'm not an experienced mig welder, I just use it when low heat input is necessary.