Q. I bought a 1949 Chevy panel truck to use as a shop truck for my custom touring motorcycle seat/cruiser clothing company. I acquired the truck mostly finished on a 1998 Explorer chassis. As you likely know, the ’47-53 Chevy 3100 series trucks have five vertical grille bars that peak forward. My top two are fine, the middle bar is slightly dented, fourth down has more dents and the bottom bar is pushed in almost flat.
How hard would it be to disassemble the grille and hammer the damaged bars back into shape? I am fairly good with a hammer and dolly, since I have built a few motorcycle seat pans. The truck is rat rod themed, but I still would like it to be right, as the build was done by a body man, and the body is straight. Grilles are available new, but if I can save this one, at least I can say I did some bodywork on it.
Thanks for the great column!
Winter Park, FL
This column discusses repairing damage to a grille like this one.
A.Cool truck, and it’s one of the very few four-wheel-drive early panel trucks I’ve seen! Disassembling the grille is pretty easy. Once you have it apart, you can start with the bar that has the least damage. Probably some hammers and dollies will be the only tools you’ll need to straighten it. Sometimes for dents in constricted areas such as grille bars, I place the bar upside down on a flat block of wood, and I hammer the dents out against the block. If the dent is particularly bad, you may need to use some heat from an oxyacetylene torch, too. Since I presume the bars will be painted rather than plated, you can use a little body filler, too.
If you have good success on the first bar, move on to the next one, and see how successful you are with it. The damage on the lowest bar may be a good-sized challenge for someone without a lot of experience, but it CAN be straightened, with enough time and effort. You can always buy a replacement grille bar if the going gets too tough (and personally, I probably would take that route, at least for the worst bar).
Q. I’ve been doing a little aluminum TIG welding, and have noticed a difference in making a puddle with cast aluminum parts versus extruded aluminum. Do you have any tips to help with the process, or is it just me?
Winter Park, FL
A.There are many, many different alloys of aluminum, and each has its own unique properties. Extruded aluminum is usually 6063 alloy (it has traces of silicon and magnesium added to it), and it’s one of the easier alloys to weld. 5356 and 4043 filler rod work well with this alloy.
Unfortunately, in the world of cast aluminum, there is a wide range of alloys used: some of them weld nicely, and some are not feasible to weld at all! Silicon is commonly added to the aluminum alloys designed for casting – you might think of it as a sort of a “wetting agent” for molten aluminum, and it helps the metal to flow into minute mold cavities. 4043 filler rod is recommended for most cast-aluminum alloys, since it has a high silicon content.
The strongest cast-aluminum parts (engine blocks and bellhousings, for example) usually have magnesium added to them. These alloys are best welded with 5356 filler rod.
Zinc is another metal that is sometimes alloyed with aluminum for casting, since it is exceedingly good at helping the molten metal to flow, but the higher the zinc content, the more difficult it is to weld. “Pot metal” is the slang term for material with a very high zinc content. Zinc gives off a fume when heated, which will often pollute the argon shield that the TIG welder forms around the weld area. For this reason, pot metal is nearly impossible to TIG weld, but there are special filler rods designed for this material, which utilize the gas welding process. One widely known resource for pot metal welding supplies is the Cecil Muggy Company, (866) 684-4993; www.muggyweld.com.
You can email your questions to Professor Hammer at firstname.lastname@example.org, or mail to Professor Hammer, c/o CLASSIC TRUCKS Magazine, 1733 Alton Pkwy., Irvine, CA 92606. You’ll receive a personal reply! We’ll print your name and city unless you request otherwise. Ron Covell has made many DVDs on metalworking processes, and he offers an ongoing series of workshops across the nation covering all aspects of metalworking. Check them out online at www.covell.biz, or call for a current schedule of workshops and their free catalog of DVDs. Phone 800-747-4631, or 831-768-0705. You can send a request by mail to: Covell Creative Metalworking, 106 Airport Blvd. #105, Freedom, CA 95019.