"Basics of Basics" Spot welds, removing welded on panels.
“Basics of Basics” Spot welds , removing weld on body panels.
By Brian Martin
I remember how I fought removing my first quarter panel for replacement. It is pretty intimidating to cut into that body and remove a piece of it. But think about this for a moment, it isn’t one piece, it is many pieces stuck together with “fasteners” (the spot welds). It is no different than any other group of parts on the car, that quarter panel comes off the same as the front fender does, only using different tools. The body isn’t molded in that shape out of one piece of metal, it is made up of many pieces and assembled and it can be disassembled. Removing the quarter isn’t any different or more difficult than removing the front fender, it simply takes different tools and a little more time, but it is really no different. Could you remove that fender without any tools? Just walk up and remove the bolts with your bare hand? Of course not, and you can’t do that with the quarter panel either. You simply need to grab different tools than you use to remove the fender. Just like removing a bolt, you grab that bolt with a tool, a wrench or socket and ratchet and rotate it until it leaves the nut freeing the part from it’s grasp. The spot weld is no different, you get a tool and remove the spot weld that is holding a part to the adjacent part, it is literally that simple. I have called removing weld on panels “unbolting” for years. It’s all a state of mind, and knowing the methods can make it that simple. Let’s look at a few ways to get the job done.
Spot weld drills are the cleanest way to remove the spot weld. There are a few different kinds with each one having its good and bad points. I will sometimes use a few different ones on your typical large job but you could do it with any one of them. Here are a few examples of sizes and styles. (photo #1)
One of the big differences is the pilot tip of the bit as you can see in photo #2, the one on the right has a much larger tip. The spot weld it drills out will have a hole in the center of it. (photo # 13) Now having a small hole isn’t a big deal as you may choose to weld thru that hole (making it a little bigger first) from the backside into your new panel. Why drill a hole in the new panel for the plug welds, when you have these little holes in the underlying panel anyway?
Where as the smaller tip still will put a hole but not quite as big. (photo #12).
The smaller tipped one is a little more precise a cut, the larger tip is a more of a workhorse. It will allow for a lot more error in your drilling skills. If the metal isn’t perfectly flat, if the spot welds are rough old technology welds, the one with the longer tip is going to last a lot longer and do the job with less headaches as it won’t wander. If you have smoother spot welds and would like to use the one with the smaller tip I recommend a drilling a little point into the center of the weld with a 1/8” bit to help the spot weld drill stay centered. (photo #10)
There are spot weld drills with even smaller tips. For the smaller pilot tip you need some kind of tool to hold the bit perfectly straight. There are a few like the “Spotle”, Blair, and some cheap copies. I have a Spitznagel that I wouldn’t give up for anything. This isn’t a tool for the home hobbyist at almost $1000 with the extra clamps I have, but man oh man is it a must have for the pro. (photo #3) It drills out the welds effortlessly with just the pull of the trigger. The tool clamps it’s self, trapping the weld, the bit then extends out and drills the weld with an adjustable depth! (photo #4) You can drill out weld after weld with lightening speed because you don’t have to think about drilling too far or too little to remove the weld.
It leaves the smallest hole in the underlying metal. (photo #12a)
There are others such as the “Spot-eze Pro” with an adjustable and replaceable 1/8” pilot drill. It works pretty much the same as the one on the right in photo #2. There’s also the old standby “Blair” spot weld “Hole saw” style with a retractable pilot tip. I haven’t used a Blair in years, decades actually. I thought they were gone, history, it was probably the first available on the market. I was very surprised when I asked if anyone had one in the shop so I could get a photo of it and I learned one of the guys uses one everyday! (photo # 1a) And of course like any pro he has an air drill with it permanently mounted in it along with a smaller air drill with the 1/8” bit for making pilot points as well. See photo # 13a for what it does.
It doesn’t remove the weld like the others, but separates the weld from the surrounding metal. After removing the panel you simply grind the weld off that is left with a little angle grinder or similar tool.
Other than a spot weld drill you can also use a cut off disc in a die grinder for removing spot welds. (photo #25)
And how you would go about doing this is to set the cut off disc vertically on the spot weld and move the tool and disc forward and back over the weld grinding the weld away. (photo #25a)
Leaving the area looking like photos #26 and 26a. Obviously this isn’t the cleanest way to remove a spot weld. Bit it is often needed for a number of reasons. Everywhere from poor accessibility to larger poor spot welds often found on older cars. These welds were done by humans not robots and they were often grouped poorly with one over another. If you want to save the panel you are removing this is not the method to use, but can be if you must. If that panel is being thrown away, this is a perfectly good method. I have seen guys in shops use this method on every panel they remove. Personally, I will use my Spitznagel and get it done a lot faster and without sparks flying all over. But using the die grinder and cut off disc is very common around body shops.
This method is perfect for removing a weld bead. Some panels will have a short bead placed at the edge of the panel in a strategic place to hold it along with the spot welds. If you make a cut along side of that weld bead you can remove the outer panel and then grind that weld bead flat once you are done. As in photo #26b, I didn’t split it or grind the weld away, but you get the idea.
Here in photo #26c you can see a weld along the edge. Photo #26d shows it with the weld ground off using the die grinder with a cut off disc on edge. And then in #26e you can see it split apart.
How about a brass tacked panel. This is common where a tack of brass was applied right at the end of panel for added strength. This is an old Rambler “A” pillar but I have seen brass like this on many cars over the years including late models. A 2000ish Toyota Camry has a tack of brass on the upper quarter at the C pillar. Again as photo #26f shows one of the options on dealing with this brass. I simply cut above it, if the upper piece is being discarded anyway, why ***** foot around, just cut it off. Photo #26g shows it split apart easily. Then in photo #26h you can see that I cut away the little piece that remained. I cut it with a cut off wheel and the die grinder, reducing it to just the brass. Then I ground the brass off with an angle grinder and a 3” 50 grit disc to get it down to the metal but not trying to remove it all, you don’t want to grind all the metal away. I then changed to a 3M “Surface conditioning disc” and simply removed the brass with it. The Surface conditioning disc will remove the brass as it is softer than the metal around it.
The other way of course would be to cut thru the middle of the brass at the edge of the metal. The brass flows out and under the panel like glue so you aren’t totally separating the panel from the brass as some will remain between the panels but that is what your panel splitter is for. (photo #26i) And with a little separation help from the panel splitter and you have photo #26j. A little grinder and Surface conditioning disc and you would have shiny metal with the brass gone.
Ok, so we have a good idea of what tools can remove that spot weld, the other part of the puzzle is after that spot weld is removed, removing the piece from the structure. This is not as simple as just pulling it off like a fender once you have the bolts out. Almost, but not quite, you need to perform some delicate surgery. The panels are often stuck together with undercoats, primers, seam sealers and the like. There is also the simple fact that you won’t be able to remove every spot weld perfectly. From the sloppy spot welds of many older cars, to the fact that the metal isn’t perfectly flat and the drill wanders a little, you simply are not going to be able to remove every spot weld as nice as you would like. One of the first things to help in this is before you drill them out, you cut away the panel leaving only the strip of metal where the spot welds are. As an example here on my Rambler, (figure #5) if I were cutting the quarter panel off I would want to cut on that red line over the wheel well removing the quarter above it. The rest of the quarter would be cut the same way, just around the edge so the spot welded areas stay. What this does is give you access to the backside of the welds and allows you to split the piece of the quarter off the underlying panel. If you didn’t do this you would have to go from inside the wheel well to split the two panels. Though not impossible it would be much more difficult. With that outer quarter removed you have full access to the area between the panels and you can split them apart much easier. In figure #6 you can see the same idea if I were removing the roof skin. I would cut along that red line, all the way of course not just a foot like I did for this example. The roof is welded down in the gutters, it would be very difficult to split that panel off the gutters without removing the roof skin first so I could come in from the back side to split the panels. Figure #6a shows what’s left of a Honda quarter panel that was cut away to make removal of the welded area easier. If you go back to photo #26e you can see how I cut away the pinch weld that was in the way of me getting a nice angle for my panel splitter to slip in between the panels. I actually could have gone from the backside just as easy but sometimes you can’t and need to cut away something out of your way.
So on to actually splitting the panels apart. My favorite panel splitter of all time breaks one of my biggest rules around my garage and home, using the correct tool for the job. Few things aggravate me more than seeing a tool of mine misused, yet here I am misusing a beautiful Snap On gasket/carbon scraper (Photo #7). This is a very old one, been using it for decades. It’s part number is CSA12-A and can be found used on ebay and such for about $20. I have seen it with and without the A at the end of the number so I am not sure if it is still available using that number. Mine has been beat on for decades with a hammer, it has held up well and I have found it to be the perfect tool for this job. The so-called “panel splitters” that I have seen sold are all much more clumsy, made of thicker metal and just not as good as my Snap On gasket scraper in my opinion. I also modified it by grinding the sides to a blade just as the business end of it had. (Photo #8). This allows me to push it in between panels sideways to get a better shot at a weld, more on this later.
Photo #9 shows my “splitter” being pushed right in to that spot weld without even hitting it. This is how a lot of welds will split when using a quality drill, the weld is removed and I simply pushed my splitter in between the panels without so much as a grunt.
Another few photos (#17 and #18) with it in action.
Without a doubt, the most important thing when splitting the panels is to go from the correct direction into a stubborn weld. When you have a little weld still hanging on you need to come from the backside of it. (photo 22a)
Doing this will break the grasp of the weld without tearing the surrounding metal. When it does tear, it tears INTO the drilled out area. It takes a little practice but you will quickly learn which way to place the splitter, upside down or right side up. With the tool sharpened so that one side is flat, this gives you a lot more control and options. You usually want to place the flat side up against the part you are cutting off, which is the part with the hole drilled in it to remove the weld. That way the tool is cutting up at the top of the spot weld and it will tear the metal INTO the hole you have drilled.
Photo #22 shows a spot weld that was drilled off center a little, a portion of the spot weld has remained. The splitter will be pushed in between the panels going against the back of the weld as shown.
Photo #23 shows the weld once the splitter has been pushed thru it with a little strike of a ball peen hammer.
Photo #24 shows the weld on the inside between the panels. This would be perfectly flat with one quick hit with the grinding disc. Which by the way would be a little 2 or 3 inch 50 grit disc on an angle grinder. It gives you all the control you need when removing such small pieces of metal.
But do it wrong, go from the other direction, it’s a whole new ball game. (photo 19a)
Let’s try another spot weld drilled a little off, this time we will go from the wrong direction. (photo #19) Now here is the splitter after it was hit from the wrong way in figure #20. And photo #21 shows you from the bottom side what happens. The metal split because the spot weld at the edge of the hole was stronger than the metal around it.
Here is an example of how to get that splitter into position to cut the remaining weld from the correct direction. In photo #27 you can see the spot weld that was removed with the cut off disc and a die grinder. I am going to split it apart so I slide the splitter in between the layers of metal. First off, you may be able to see that the right side of the ground area has some bluing to the metal. This is because that side was ground thinner, that side is ready to be split. The metal gets to a point that it is so thin it heats very easily from the friction of the cut off disc to a temp which blues it. The left side of the ground area isn’t blued so you know that it didn’t completely grind thru the upper layer of metal. Not that it will blue every single time, but this is a good indicator as you are grinding that you have went far enough. So in the photo you see me pushing the splitter in but that is as far as I can go, seeing that the left side is still attached a little I stop, if I were to hammer it thru I would likely get that metal splitting like in photo #19a.
To be continued......
So what I do is come from the other side as in photo #28. Now, to get the splitter down in there I simply strike the side of the too with a hammer pushing it in. This is where the grinding of the sides of the tool come into play. Yes I am hitting on the sharpened edge and that will dull it. It isn’t razor blade sharp and if it gets dulled a little it won’t make one bit of difference in the function of the tool. Besides, one quick pass with the grinder and it’s sharp again. Like I said earlier, I don’t like to miss-use a tool like this. But it works so darn good I have to look at it as a “consumable” like a throwaway paintbrush. If I need to throw it away, I will and buy another for the next job. But it hasn’t worked out like that as I have used it for decades. At this point a light tap with the hammer sends it in between the layers so I can then strike the splitter at rear of the handle like a chisel and split the remainder of the spot weld without tearing the metal. (photo #29)
What if the weld is bigger than the drill bit? How about one of those old welds on a vintage car that was done by a man holding the spot welder on a Monday morning after a weekend of boozing (you know that really does happen) and the spot welder got moved during the weld so it isn’t round but oblong shaped. Well, by drilling a few pilots as in figure #14 you can make a long slot in the upper layer of metal removing that stubborn odd shaped weld.
Drill out the metal and weld in each of those spots as in photo #15.
And you have a perfectly “Unbolted” panel. (photo #16)
Well, that should get you started. After a few welds you will get the hang of it, how much to drill is a biggie. You just drill a little and look, maybe even get the panel splitter in there and work it a little trying to separate the panels, then drill a little more when you find it isn’t enough, then check again with the panel splitter. Taking your time and splitting the panels without distorting the underlying panel is key. You can do this easily sometimes, other times not so easy and you have to hammer and dolly the underlying panel before you weld on your new one. That’s just part of the game, but if you take your time you can “unbolt” it just as you do your fenders up front. The more time you spend on splitting the panels the less time you will have to spend on cleaning up and straightening the metal.
Now go take that body apart!
Excellent tutorial. Thank you!
You're welcome. :thumbup:
This is such a good write up! I like articles that explain how we do it, with pictures, and why.
One question, I have only been able to find the Blair spot weld saw in my local body shop suppliers. What are the sources on some of the other spot weld saw brands you mentioned?
I have found that the Blair saw sometimes skips around as you start to enter the metal with it, and drilling the 1/8 pilot hole really reduces that tendency. Also, if you are reusing panels and because of welding access, you need to fill in the 3/8 hole made by the saw, before attaching two or more pieces together, do you know a source of 3/8 sheet metal plugs, or slugs to fill in the hole on the bottom panel of the weld?
What you have described here is pretty much how I remove welds to a "T." However I have the spotweld cutter shown in 1A and find it to be almost absolutely worthless. It jumps all around and will still easily cut through both pieces of metal! In order to use it I drill a small pilot hole in the spot--just enough to make an indent, then put the cutter pilot point in that indent and it's usually enough to keep it from moving around.
I remove most of my spot welds with a pneumatic 3" cut off wheel like you showed. I like it because I think it keeps the metal underneath the most intact, but I first drill part of the spot weld out with a 1/4" bit (but don't go through the metal). This removes about half of the metal to the weld then I finish off with the cutter. However, as it is with most things, no one tool or method is good for universal use, so I find myself using all of these tools and methods in the removal of any given panel.
Your description of the Blair is how I remembered it, and I honestly didn't think they were even available anymore.
Grinding the metal is loud, throws the sparks everywhere and it just so happens that the position I need to sit in or lay in is the exact position where it will throw all the shavings and metal on my arm and burn it or in my face, so then I have to contort my body somehow. I've also started wearing my respirator when doing this lately, because the smell and fume that comes off the metal really irritates me and after awhile would start giving me a headache.
I saw this trick in a Ron Covell video years ago, (VHS video if that tells you how long ago). It was in the first five minutes of the video and I could have turned it off and tossed it in the garbage as this one tip was worth the video price. It's in "Basic sheet metal working" and I HIGHLY recommend it if you want to learn a bunch more like this. Ron is a master and genuinely nice guy. Ron Covell Creative Metalworking Workshops
Using the punch you knock a slug out of a piece of similar metal.
You then set that piece in the hole and with a dolly behind it you tap the slug flat enlarging it's size so it holds it's self in the hole!
Is that cool or what! With different thicknesses of metal you sometimes have to clean up the edges like I did this one so the slug will fit in the hole. But typically the best way is to punch a clean hole punching the drilled hole out of the metal. That way you have a perfect round hole for your slug. But it will often need a little enlarging with a rat tail file to accommodate the slug.
Brian, I have found that if I drill the hole 1/64 larger than the hole plug, it works good, although just tight enough to hold it. And the I have to use the step drill bits to get a round hole.
NOT these (my opinion)
I have a number of pairs so I don't have to hunt for one if I have misplaced it. And so my kids can put them on if they are in the garage.
But my absolute favorite are the ones with the radio. They are about $50 and I feel well worth it. I use them when mowing the lawn, I can go on working listening to my baseball games or what ever, they are THE way to go for me.
And by the way, there is NO WAY after owning that Roper Whitney I would be doing fab or restoration work without it. That and the Roper Whitney "Jr" a smaller version with different sized punches, they are worth their weight in gold if you ask me.
I do have the Ron Covell videos, and have been to a few of his seminars at Clackamas Community College, in Oregon City, Oregon. He is a good guy, very knowledgeable, nice, and does not speak down to anyone, in his seminars. go to one, you will see. At least the videos I have from him are on DVD.
I have heard of the Whitney Roper punch, and even looked into getting one. Unfortunately, the 7A "junior" is not recommended for sizes larger than about 5/16, so I would need the next larger size of punch, and that was about $200, when I finally found one. That is a little spendy, but I think I am going to have to "bite the bullet", and get one
And if you ever wanted to punch other shaped holes they have the dies for that too!
Roper Whitney - Quality Sheet Metal Fabrication Equipment
I picked up the Jr at a garage sale for only ten bucks or something I forget, but it was a killer deal. Bought the XX years ago and never regretted it.
Covell, oh heck yeah that guy is so friggin easy going. I wish I had his people skills but they are all natural to him. My brother and I had just did your run of the mill hot rods never any real fabbing. At a Grand National Roadster show (when it was in Oakland, damn I miss it) he had just started doing his classes, this was about 1989? My brother and I were talking to him next to a beautiful A roadster that he had there on display in bare metal. We were drooling over it and basically telling him how we wish we could build such a car. He looked at us and said something to the effect of "You can, I am not special, you can do it just as I did". It blew us away and I am not kidding you, we left that meeting with Ron different people. We went home and built a very special car, a super detailed very special car and I KNOW Ron had a big hand in making it happen. All from his nudge that he gave us that day. Very cool guy, he is one down to earth ego-less genuine guy that is for sure.
|All times are GMT -6. The time now is 01:03 PM.|
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.