and Welding Seminar
by Terry Gaskin
I recently attended the Sheetmetal and Welding seminar hosted by Carl Heideman of Eclectic Motorworks in Holland, MI and I wanted to share my experiences with you. Carl’s shop performs restoration work on all types of classic cars, but he mostly specializes in MGA restoration. As part of his restoration service he offers several seminars that teach the basics of welding and sheetmetal repair, advanced courses for MGA specific restoration and in conjunction with John Twist of University Motors, the Tuning for Speed seminar which has been documented in past issues of the Driveline.
Bodywork, welding and fabrication are parts of the classic car hobby that have almost a mythical quality about them. Most folks can perform mechanical repairs on their British classics, but bodywork is where the hobby can become intimidating. With even the youngest MG’s being over 20 years old, almost everyone in a northern climate will have to deal with rust repair or the occasional dent. While books and on-line resources document the various skills needed to perform bodywork, nothing can compare to actual hands-on training. Carl’s seminar is an excellent starting point for learning the various facets of metalwork.
The seminar covered all aspects of working with metal: cutting, stretching, shrinking and welding. Each topic was presented using various examples of tools, methods and examples of the end result. While Carl’s shop has professional quality tools, he did illustrate more basic methods of obtaining similar results with more simple and less expensive equipment. I’m sure everyone wants Snap-On quality tools but can only afford Craftsman or whatever else is used to ‘make do’.
The various metal shaping machines and tool. English Wheel.
For cutting metal, shears, nibblers, and snips were illustrated and the proper method for using each was shown. One helpful hint that was given was to first make a rough cut and then complete the cut using snips. This allows for a more accuracy and makes fitting easier. For cutting, it was recommended to use a die grinder with 3M’s 3" diameter 1/32" thick cutoff wheels (part # 3M 01989). Also shown was the use of electric shears. These made cutting the 20 gauge sheetmetal almost effortless and would be invaluable in cutting large panels.
Welding techniques and exercises were covered in depth. The basic theories behind welding were explained along with the various types of welding. Since it is the most widely used, MIG welding was the primary focus. Carl taught that correct welding is 75% preparation and 25% skill. Proper preparation of the piece being welded was shown, as dirt and grease will contaminate the weld, rust can’t be welded and neither can air. Time spent in preparing the piece will eliminate a large number of problems commonly encountered. Also shown was the proper way to orient the gun tip to the piece. 15 degrees off of perpendicular to the piece was recommended as the correct angle to hold the gun. This maximizes the gas shielding while allowing for the puddle to be seen. Proper posture and holding the gun with two hands were mentioned as ways to improve the quality of welds, as was proper mental attitude. Being in a good mood was suggested as playing a critical role in creating good welds. Frustration and being tired can lead to sloppy work and errors can compound quickly. One strong suggestion was that when beginning a weld and it does not start well is to stop immediately and fix the issue causing the problem. Attempting to readjust ‘on the fly’ usually doesn’t work.
Panel beater station with various hammers
Four basic welding exercises were illustrated: ability to weld following a line, completing a lap weld, completing a rosette (plug) weld and performing a butt weld. Each exercise introduced basic welding skills and the methods learned in one exercise were then applied in the following exercise. In addition to teaching proper techniques, the welds were analyzed for penetration and any faults were examined. By reviewing the work, corrections could be made immediately and the quality of the welding greatly improved as the day wore on. The last exercise (and most intimidating) was completing a butt weld. By applying what was learned previously, everyone was able to complete a butt weld at the end of the class. One good tip was to only clamp at one end of the panel and beginning tacking at that point. Then, every inch or so, place another tack weld working along the joint. Finish the weld by stitch welding between the tacks. When lining up the panel, it was suggested that a gap of approximately the thickness of the panel being welding be left for each foot of length of the joint. Since welding actually shrinks metal, as you tack along the panel the gap will close, aligning the panels perfectly. This gap allows for the metal to move and minimizes warpage. In addition, it was suggested that any warpage be address immediately during the welding process by hammering on the still cooling welds. This reduces the amount of work needed in finishing the panel.
TIG welding for aluminum panels
As a supplement to welding, techniques for the proper grinding and finishing of welds was also shown. It was suggested that a cutoff wheel (3M’s 3' diameter 1/16", part # 3M 01990) in a die grinder be used to grind the weld rather than using an angle grinder. This allows for only the weld to be ground rather than the surrounding metal when using an angle grinder. The weld can then be finished using 36 grit paper in a 2" air sander. The finished results were very impressive in their appearance.
Various forms of stretching metal were covered. These included bending, using hammer and dollies and using hammer forms. The theory of metal stretching was covered, and examples of how it is used were shown. One important concept illustrated was ‘sneaking up’ on the piece. Begin slowly, working a little at a time. Using brute force doesn’t work and will most likely create even worse problems. By using the front of an MGA that had some dents as an example, Carl showed how using a hammer and dolly can easily remove dents. He then showed how to use a file to locate any high spots. An interesting item was the use of hammer forms to create panels. Using a pattern created in aluminum (wood can be substituted...aluminum is used when the hammer form is to be used repeatedly) an interior panel for an MGA complete with proper flanges was made. This method can be used to make ‘home made’ panels and will definitely save money. In bending sheetmetal Carl uses a large industrial brake. However, since most people don’t own one, he showed how to create a 90 degree bend in sheetmetal using a bench vice and two pieces of angle iron. Clamp the two pieces of angle iron in the vice with the piece sandwiched in-between. Using a plastic mallet, slowly pound the piece into a 90 bend. Again, sneak up on the piece by working slowly and the results are nearly as good as a brake.
Fixture for MGA body alighment
Shrinking metal was also shown in the seminar. Two methods of shrinking were illustrated: cold and heat shrinking. Carl suggested that most issues can be resolved using cold shrinking. Cold shrinking consisted of lightly tapping on the high spot with a hammer. Working slowly and with a light touch appeared to be the key. He also illustrated heat shrinking and some of the problems that are commonly encountered. Most surprising was how little heat is needed (just enough to make the metal start to turn red) and the small area that needs to be heated (dime size). In addition, the proper amount of hammer force was shown, which isn’t very much. Repeat this process across the area needing shrinking, remembering to keep the area heated dime sized.
In addition to these four areas, Carl let the class pick a couple of other topics to cover. He gave us a brief introduction to TIG welding. We were then able to try welding using some of the previously shown exercises. Carl uses TIG welding when working on the outer panels of a car, and the quality of the welds shows why he does. Although the cost and skill level required are much higher than MIG, the end results are impressive. Also shown was the use of the English wheel. We took a roughly shaped piece formed with a mallet and shot bag and were able to smooth it into a usable panel. While a hammer and dolly can be used, the English wheel can complete the process in minutes. And yes, it does hurt when you get you fingers caught between the anvils...I’m speaking from experience here.
Overall, I felt that the seminar was invaluable in presenting the basics of sheet metal repair. Enough topics were covered in enough depth to be given a good grasp of the fundamentals involved in metal work. I would recommend the seminar to anyone starting off in metal repair and the skills learned here will definitely help when working on your car. I have already tried some of the items taught and have improved my welding ability.
For more information visit: www.eclecticmotorworks.com