SPI Paint Products For Wheel Arch Repair

And brother, I appreciate it!!! Won't be anything like this on the Mustang. There is a science in working with sheet metal and I've not even scratched the surface. That whole thing on oil canning, which is something I feared in this repair, scares me such that I'm scared to take a hammer and dolly to a dent now. I have so much to learn and that is why this is such a great place to be!
 
…...Won't be anything like this on the Mustang. …….


Some may look at a thread like this and think.....it's only an 86 F150, who gives a schitt if its butt welded or flanged? Who cares about a ghost line, it's only a beater truck?

The Mustang was mentioned in the initial post, and whether you're putting in floor pans (another typical who cares area) or outer Sheetmetal in this truck, I've always said, it all serves as good practice to hone one's skills for where it does count. Do it once, do it right.
 
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Actually, this 86 F-150 is one of the nicer ones you will see but it is indeed the sacrificial lamb for the Mustang....LOL! I have the driver's side patch welded in, but I'm not ecstatic about it. I'll be sending you some pics, Robert. I followed your instructions on planishing the welds and I did well minimizing warpage with the exception of what I showed you above. But, there appears to be some overlap in the horizontal weld such that I cannot blend the weld seam flat to the panel. I hate to half-ass anything! Thinking I may cut it all out and re-do. Appreciate ya!

BTW, when this is over, this thread could be edited and put into the metal section. I searched the internet for a quality video and description on cutting out these wheel well arches and found little quality information. Much of what I found would be considered half ass.
 
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So, not fully pleased with my work on the driver's side wheel arch and needing to repair the other side, before I cut out anything I'd like some opinions and thoughts??? Attached is a photo of the damaged area and another photo of my proposed area of cut out. I would make my cuts inside the blue fine line tape. Note the radius. Is this where you would make your cut? This will be butt welded fully.

Also, attached is another picture of the first repair, driver's side. You can see the warpage in this picture. I'm not sure I can take that out with hammer and dolly due to the flange and all. I'm anal and it bugs the crap out of me. I do not want to half azz the repair. If I cut that out and weld in another patch panel, could the current warpage be alleviated?

For me, I'm learning and this is more about doing it right than anything.

Thanks,

John
Rt Wheel Arch 1.png
Rt Wheel Arch 2.png
Panel distortion.png
 
If you cut the patch out larger than the heat effected zone, most of the warpage will likely go away once the stresses of the weld are removed. This assumes your hammer and dollying has been limited to the weld area.

John
 
Is this the flange repair or did you butt it like we were talking about? Irregardless first thing I would do is get a dolly behind the weld and see how much will dolly out. Dolly on the weld, hammer only on the weld, make the dolly ring. start at one end work to the other. MIG welds are hard and don't like to dolly out easy so you'll have to make several passes. If it's butt welded this will work better than if it's flanged.
You shouldn't be getting that much warpage if you are MIG'ing it correctly. To me it looks like you started at one end and worked to the other? Remember fit it tight, then spot it with the MIG. skip around till you have it fit enough that it is attached. Meaning enough welds that you don't need clamps magnets etc to keep it in position. Once you do that continue spotting it in moving around, panel should never get hot. Spot means just that . Position the MIG gun, pull the trigger, less than a second done. Move to the next weld. Don't start at one end of the weld and work to the other. Move around the full perimeter of the weld randomly. After you have done some spot welds on the panel say 15% of the seam is welded, grind those spots down as Robert described. Use a die grinder and a weld grinding wheel like this

DSCN0640.JPG
Helps to to use a wire brush or wire wheel brush on a drill to clean the weld seam as well occasionally while you are welding. THen keep spotting randomly. Work to a point, then grind again. Continue this process until you have it fully welded. Be patient.
Only reason you would get excessive warpage using the MIG is by trying to weld too much too fast.
 
Chris, I gave him the short answer as he stated in his post this was a flanged repair. It has pulled ripples all the way up to the body line. I may be wrong, but I don't think all the hammer and dolly work in the world is going to take that much shrinkage out of a flanged repair.

John
 
Now that I'm done with Powerpoint….

Let's talk about the distortion....

Panel distortion.jpg


With a normal butt weld, the weld shrinks or to explain another way, the length gets shorter. Two inches or so outside the weld area, the panel remains cool and resists any change. The area between is what's caught between two differing forces, and forms an up and down wave as the metal looks for someplace to go. You would normally planish along the entire length of this weld to stretch (add length) back to the weld and HAZ area, and the wave would relax as those forces equalize.

It's hard to discern if there is any wave action above the flanged area, if it is not, then perhaps the two layers helped to keep it from distorting that side. But any planishing in that area is now near impossible. The first area past that now becomes the weak area more susceptible to the shrinking effects. This is why the distortion is focused in those corners instead of waves along the entire length. With as much of a pucker as you have there, it will be near impossible to remove the distortion. Don't know how much the replacement panels cost, but I would say two inches outside of the weld would be needed to remove most of that distortion. If any distortion remains after that it should be easily planished out. The corners should be cut out as a radius, even larger than you show in the next picture.

Rt Wheel Arch 2.jpg


All options surmise that inner wheel well is removed for planishing access.

Looking at the proposed cut at the blue line, I feel this is too close to the reverse (inward crease) that a weld will cause distortion in the crease, and the close proximity of the crease will make it difficult to planish with hammer and dolly. So that is not a good option. Moving lower may bring the weld too close to rusty areas, which may be a recipe for blowing holes. If there is room to bring it lower and more centered, this would be a good location.

Looking at the proposed red cut line, IMO the distance between the two creases are too close that shrinking is going to try and pull the creases together. With rear access you would be able to planish, but the limited "target area" may make it challenging. So this option is based on your comfort level.

For all the conditions (rust, body lines, etc) I would prefer the yellow cut line. This does take you across two creases that will tend to pull inward and need localize planishing in the creases to bring them back out, but I think this would be the best of the options (if the rust below is a detractor for that area). For the yellow cut I would try and hold the distance at 1" from the top crease, so not a straight cut but one that follows the radius of the crease. If the rust had been caught earlier on, a midpoint cut below your blue line would be preferred.
 
Not arguing with you Robert, I totally agree with the radius, but I've done a ton of those type of patches cut square, Stuff that they don't give you the time to make a nice radius on and never do they pucker like that if you don't put excessive heat in the panel. No matter how you cut it the most important thing is to weld it correctly. Spot it and skip around. To be clear Machspeed a correct spot weld lasts no longer than a second. Position the gun,pull the trigger, less than a second, release. Move on to the next spot weld.
Another thing to think about that may be helpful is how you fit it. I find that with the MIG, when I know I will skim coat the weld area, the best way to fit it (if I have access to both sides) is to first overlap the replacement piece. Then use a couple of self tapping sheet metal screws to hold it in place. Then use a thin (thinnest you can find, 1/32, never use a 1/16) cut-off wheel to cut through both pieces in the overlap area. Usually start at the center and work out on both sides equally. Do several inches, peel the cut layers back, use a small screwdriver to help manipulate the two pieces of metal in place and tack. Continue doing that until it is tacked in place. Continue spotting until welded. Doing it that way gives you a small gap between the pieces which always seems to help with distortion and controlling it. Do it right, you'll have almost no distortion even with square edges. When you no gap using MIG it makes it harder to control the distortion especially for a novice.
 
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Let me add a little to what Chris is saying. I know he and Robert know this but there may be some readers who are interested in learning. The amount of gap to leave is always a major discussion with many skilled metal men disagreeing on whether to leave a gap or not. Fitting and welding a panel with zero gap is great for an experienced, skilled body man but it does require more welding and planishing skill for this reason.

When you begin to tack the panel and it wants to shrink it will pull the two panels and the edges will overlap. Skilled planishing with accurate hammer blows will stretch the tack out and the edges will return to their correct location. BUT, if you miss the tack and hammer the unaffected area, you have now grown the panel by thinning the metal along the edge. The edges will overlap even though the panel is back in it's correct position. At this point your stuck. All the planishing in the world will not fix it.

Keeping your butted edges properly aligned, planishing only the weld itself, and going very slowly will prevent this but it does require practice and a high level of skill. By leaving a small gap of .0020 to .0030 you have a small amount of leeway for the metal to be stretched without having to deal with the overlap. In any case, the secret to a successful repair is keeping the panel in shape, planishing as you go. Waiting to planish it back after you have finished welding is not the way to do it.

None of us made a perfect repair our first time, I promise you. Good luck with it.

John
 
Gentlemen, thank you, you guys are great! Observations from first repair attempt that may not show in pictures: There is no apparent warpage in the long horizontal weld where it was flanged, nor any in the vertical welds where it was butt welded. The warpage appears limited to that area above the repair at both corners as pictured. This appeared before it was fully welded too. It is excessive. However, there is some lippage (uneven surfaces) along that horizontal where the weld shrunk and I cannot get it to grind smoothly without possibly thinning the panel. I was planishing the welds, but it being two pieces (flanged) and my limited knowledge of planishing probably was not enough. Interesting is that the vertical welds that were butt welded with a .024 gap came out seemingly fine but did lack some penetration and that is a no go too.

John, you are exactly right in the gap between panels discussion. I’ve been all over the web studying and the consensus is no gap or tight fit between panels for experienced welders and small gap for inexperienced. There is some very good discussion in the below link, but the conversation lacks the essential importance of planishing the weld which, because of you guys, I believe to be of very high importance now. I find that lack of planishing in much discussion. Robert has done a great job emphasizing it in our dialogue.

http://autobodystore.com/forum/show...much-of-a-gap-for-butt-welding-quarter-panels

Today, I’m going to practice using the left over metal from my patch repair under the higher heat settings and experiment with the trigger pull time. It appears there is a fine line between a really good weld and those adjustments. Robert, Chris, and John, Thank you!!!

On another note, anyone experiment with flanging and panel adheisive……KIDDING….LOL!

John
 
John, re: the link you posted, pay attention to what is said by Brian Martin and John Kelly, they know their shit. The other “gentleman” who learned at the age of twelve from his fathers restoration shop..... yeah, he’s the biggest hack going. He comes off as a know it all but when you see pictures of his chicken shit cold welds, the proof is in the pictures. But alas, there has to be something said for consistency. He’s been welding like that for 25 years that I’ve seen his work. Says a lot for what he learned at daddy’s shop.
 
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Yeah Robert, I quickly deduced that....LOL! There's an old adage, "there is a way that seems right to a man, but in the end it leads to death". We can learn from anyone, in his case, it is what not to do, despite compulsive insistence that he is correct in his ways. I was very impressed in how Martin and Kelly dealt with him in their responses......classy guys!
 
I’m glad you could see through his bs. You’d be surprised the amount of bad info out there. It’s one of the reasons I share as much as I can.
 
Reading that link it seems that some disagree with the gap method. I have used the method I described above for years with success. I have seen it used by other guys I would consider top tier. Now I will say there is a time and a place for everything. If I'm going to the time and trouble of a no gap fit I am not going to MIG weld it. If I am doing something high end, I am not MIG welding butt welds. Then I will take the time to get a no gap fit. I will gas it or TIG it. Fighting with planishing a MIG weld is not something I like to do.

From my own experience I can say the method I described above does work. I would not have posted it otherwise. I've used it for years. It's easier, faster and gives essentially the same results as MIG welding no gap. Anyone who says it does not, has not tried it, or done it correctly. And it takes much less time which for many of us doing it for a living, working for the man, is a reality that we have to face.
 
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Chris, agreed. More than anything I’ve seen this guy berate novices work when in fact their work put him to shame, and the disrespect he showed those other two guys, well known and respected in their industries. Just not someone I’d recommend for advise in this arena. I’ll dig up a link later so you guys can have a real laugh. A how-NOT-to.
 
Chris, agreed. More than anything I’ve seen this guy berate novices work when in fact their work put him to shame, and the disrespect he showed those other two guys, well known and respected in their industries. Just not someone I’d recommend for advise in this arena. I’ll dig up a link later so you guys can have a real laugh. A how-NOT-to.

If he got under your skin Robert, that's saying something. :eek:I've never seen you with a harsh word for anyone. On any of the boards I've seen you on.
 
It's not just doing it for a living, it's that very, very few customers have deep enough pockets to finance exacting metalwork. Even to do filler over epoxy is a cut above what 99% of shops are doing. I have utmost respect for metal craftsmen that can produce finished panels with little to no filler, and I'm grateful that they set the standard for the rest of us to follow. I was lucky enough to be taught some things by one of them, and we should follow their example whenever possible. But in the world that most of us live in, it's often not possible.

So our shop rules end up being, keep distortion to a minimum, leave NO porosity, do metalwork to within 1/16" or so of final contour if possible, make sure high spots are eliminated, do excellent metal preparation for epoxy, and never apply filler on bare metal. In my opinion, following these rules can result in a repair that is virtually indistinguishable from one where no filler was used, both from a durability and appearance standpoint.

Sorry if this is off-topic. I just don't want guys to feel too bad if the metal doesn't come out perfect. There are actually other things that in the end, are more important for the ultimate success of the job, metal preparation prior to epoxy possibly the most important.
 
Jeez, I hate to change course in this thread but crash I have got to ask about a comment you made, as it is something I thought differently about. Your comment being, "and never apply filler on bare metal". Keep in mind, I don't know much and just asking to clarify, as I have read that filler could go on bare metal or over epoxy. In fact, it seems I read that the epoxy would be roughed with 80 grit prior to application of filler. Would you enlighten me here on this? I know you know your stuff and I like to know the why's to things.
 
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