Replacing severely damaged metal and planning your repair. By Austin : Metal shaper, fabricator, and restorer of vintage automobiles The image below shows a severely damaged rear portion of a vehicle. Prior to stripping the car, this damage was covered with lead, and it actually looked pretty good! I am guessing I melted off close to 25 pounds. Obviously, all of this metal needed to be replaced. The majority of the metal was disturbed so much that it would have been impossible to companion build over the existing metal. <a href="http://s274.photobucket.com/user/alparuch/media/image-32.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-32.jpg The solution was to remove portions of the damaged metal in order to construct a framework that represented the original metal shapes. This is illustrated in the photo below. We opted not to use wooden bucks due to time and budget concerns. Also, this method allowed us to build one section of the repair at a time without loosing shape information from the car that would be needed in future steps of the repair. <a href="http://s274.photobucket.com/user/alparuch/media/image-35.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-35.jpg The next step was to create accurate paper templates to assist in the shaping process. Using magnets helped hold the paper in place, while tape was used to bring folds in the paper together. These folds represent shrinking that will need to be performed during the shaping process. <a href="http://s274.photobucket.com/user/alparuch/media/image-36.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-36.jpg Next, paper templates were transferred to the steel sheet. The first step was to bend the pinch weld flange on the break. The radius in the corner was TIG welded into place to complete the pinch weld flange. #TIP# Make a note which side to work from. I inadvertently shrank the metal the wrong direction and had to scrap a good sized piece of steel and lost about two hours of work. <a href="http://s274.photobucket.com/user/alparuch/media/image-33.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-33.jpg The next step was to shape the metal to the proper contours. As stated earlier, folds in the templates represent required shrinking to the metal. Shrinking was performed using a Baileigh M-19 Power hammer equipped with thumbnail dies. Further shrinking and smoothing was done using an Eckhold machine. The panel was then hammered to the desired shape using the Baileigh Mh-19 and planished to the desired finish. The mirror image panel was created using the same template turned upside down. This ensured symmetrical shapes on both sides of the car. <a href="http://s274.photobucket.com/user/alparuch/media/image-37.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-37.jpg Once shaped to the proper contours, new metal was temporarily attached to the car to aid in the shaping of the next panel. The following image shows the lower section cleco'd in place with subsequent panels taking shape. Some further tweaking is always necessary in order to ensure a flush butt joint. This will help produce a quality weld that will be easy to metal finish. Panel fit is paramount, so take your time here. <a href="http://s274.photobucket.com/user/alparuch/media/image-26.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-38.jpg Once a flush seam is established, cut lines can be scribed and panels can be trimmed for welding. Creating a perfect seam is the goal here, cut with diligence and file carefully to the scribe line. A seam that is too wide will result in an inconsistent weld bead size that can cause additional weld shrinkage and panel distortion. This will make finishing your weld a bit more difficult. This work is hard enough; do everything you can to make things go your way! When welding panels together in areas that cannot be reached by clamping, trimming around your clecos will leave small tabs that can be removed after the panels are tack welded together. Place tack welds approximately 1 inch apart. Once the panel is tack welded, correct any misalignment using a hammer and dolly or planishing hammer. When the seam in once again perfectly aligned, go ahead and TIG welding the seam. Control your heat my "jumping" around the panel, welding 1 inch sections. Here's a tip: using a clean copper strip or a fiberglass mesh strip secured with aluminum tape will trap a small amount of shielding gas on the back side of the weld. This will aid in weld penetration and minimize oxidation and weld contaminates. Also, always clean the metal prior to welding. I uses a wire wheel and clean the metal with acetone. A perfect weld will not require grinding and will be easier to metal finish. If the weld bead is too tall, careful grind it flush taking care not to grind the surrounding metal. When possible, I prefer to finish my welds using a pneumatic planishing hammer or power hammer. This will stretch the shrinkage caused by welding and will return the seam to the proper height. The same result can be achieved by hand, but it will take more time and effort. The panel below was welded using the techniques mentioned above. The weld was cleaned using a wire wheel. <a href="http://s274.photobucket.com/user/alparuch/media/image-27.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-27.jpg The following image depicts the completed repair. It was created by first joining the bottom two panels. Next, the middle section was joined to the side panels. Finally, the upper half was joined to the bottom half completing the repair section. The photo shows the two halves tack welded together prior to final welding. <a href="http://s274.photobucket.com/user/alparuch/media/image-28.jpg.html" target="_blank"></a> http://i274.photobucket.com/albums/jj271/alparuch/image-28.jpg The final assembly is then fit to the car, checked and adjusted as needed. It is not uncommon to have to shrink or stretch here-or-there in order to get everything to fit and flow properly. Again, take your time here; fitting is everything, and it makes metal finishing the weld much easier. With about 6 or 7 feet of welding to do, try to make the work as friendly as possible! <a href="http://s274.photobucket.com/user/alparuch/media/image-34.jpg.html" target="_blank"></a> lot of material was covered here. The work illustrated amounted to several weeks of work. There are numerous topics that could easily produce its own lengthy article. It was intended for those that already possess a strong skill set, and it is designed to show the repair of major damage from start to finish. I hope that I was able to share some knowledge with you. Please bear in mind that there is always more than one way to get the job done. The process shown above was what worked for me and this particular job. I myself am always learning. I am by no means a master. I am always open to different methods, processes, and ideas.
Great tech article and I wish I had a shit load of cash so I could haul my Model A in your direction.
Such nice work!! The tabs that you added to cleco the part to the car, how about a close up of one of them. Are they lapped or welded to the edge of the piece? Rex
Nice work. If I had your talent I would have that beautiful one-piece track nose and hood for my T roadster made up in a few months. Thanks for the encouragement.
Nice work Austin! it takes skill to make those machines do their best! Thanks for sharing your craftsmanship!
Thanks guys for the compliments. Its true, i have access to some beautiful machines that make my work a little easier... that said, some of the machines can totally screw up your hard work if your having a bad day.. like i had last friday... oh well. My dream is to get my own metal gig going, so, if you want something made... I know a guy.
the tabs that i use to cleco the part to the car... they are about 3/8 by 3/4-1 inch. When i trim my parts, I trim around where my clecos will be, leaving the small tabs.
Hey, Man, thaz some bu-tee-ful tin work! Wish ya the best of luck with gettin your " metal gig '' goin! most folks have no clue of the number of man-hours involved to build sheetmetal parts- when you quote them a price they look at ya like ya slugged their momma X number of hours X your labor rate, plus your overhead-then ask them what is it they do for a living, and the number of years they have into perfecting their craft " Do no reach greedily for the Kool-Aid ''
Thanks Man! Its nice to receive so much positive feedback. Your right- sheet metal work takes TIME. Not to mention PATIENCE and DRIVE. I hope things come my way, but im sure it will take the three things mentioned above.
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