I've been welding, grinding, dolly & hammering, and filing on all of the welds on the grille shell for the Indy car replica. It's coming together after having been cut in 5 pieces and re-formed. It's almost smooth enough to go to the plater - but not yet!
At the bottom of the grille is a decorative rosette around the crank hole. Yes, Virginia, the car was set up to be cranked by hand, but I think it would have taken an ox to turn over one of those huge straight 8s. Anyway, the hole is there and an embossed ring about 4 inches in diameter surrounded it. The rosette was attached to the shell, rather than being formed into the shell.
Note that the grille has a 120 degree Vee at the bottom. I thought long and hard about how to make the rosette, finally decided to make an aluminum die and "hydroform" it with a urethane rubber pad in a pipe on my shop press. I turned a big hunk of aluminum flat, then cut two half-round grooves in it. I got a 3-inch long piece of 4-inch schedule 40 pipe and a 4-inch slug of steel for a pusher. I cut some 4-inch pads from 55, 80, and 95 durometer 1/2-inch sheet. When put under pressure, the urethane - and many types of rubber - behave like hydraulic fluid in a bag and create uniform pressure. I also got some thin brass sheet to use for the part. The stack inside the pipe consisted of the die at the bottom, a 4-inch disk of brass sheet, a urethane pad, and the thick steel pusher. The pipe keeps the urethane from squeezing out the edges. My little 12 ton shop press started the forming process, but eventually I had to take it into work and push it with their 35 ton press to get all the detail. Here's how it looked when I got it pressed.
Then I needed to bend it to fit the Vee, so I welded a piece of 2x2 inch angle iron to a short piece of 1-inch pipe to use for a press brake. The angle iron comes with a nice radius on the edges, rather than sharp corners. I put a big piece of rubber pad under the brass part and slowly built up the pressure until I got about the right angle. If you don't have a brake at home, this seems to be a pretty easy way to make one. I tried bending some 16 gauge (.060") steel with it - no problem.
I also got the ribs back from the local sheet metal shop. They used their big press brake to form some 26 gauge (.016") steel sheet into a tight U, put in a 3/16-inch steel rod, and pinched around the rod, then pulled the rod out. That left a round bead on the edge and a 1-inch deep web to keep the ribs stiff. Once I get ribs welded in, and the last of the lumps and bumps out of the shell, then it can go to plating. The rosette will get plated separately and get attached with some studs that I'll hard solder to the back side.
Now, has anyone got a nice 1.25-inch diameter grille badge from the circa 1930 period that looks like the one at the top of the page? There a many larger ones on Ebay, but I can't find a small one in good shape.
And while you are shaking your head as you read this, remember: Anything worth doing is worth overdoing!
At the bottom of the grille is a decorative rosette around the crank hole. Yes, Virginia, the car was set up to be cranked by hand, but I think it would have taken an ox to turn over one of those huge straight 8s. Anyway, the hole is there and an embossed ring about 4 inches in diameter surrounded it. The rosette was attached to the shell, rather than being formed into the shell.
Note that the grille has a 120 degree Vee at the bottom. I thought long and hard about how to make the rosette, finally decided to make an aluminum die and "hydroform" it with a urethane rubber pad in a pipe on my shop press. I turned a big hunk of aluminum flat, then cut two half-round grooves in it. I got a 3-inch long piece of 4-inch schedule 40 pipe and a 4-inch slug of steel for a pusher. I cut some 4-inch pads from 55, 80, and 95 durometer 1/2-inch sheet. When put under pressure, the urethane - and many types of rubber - behave like hydraulic fluid in a bag and create uniform pressure. I also got some thin brass sheet to use for the part. The stack inside the pipe consisted of the die at the bottom, a 4-inch disk of brass sheet, a urethane pad, and the thick steel pusher. The pipe keeps the urethane from squeezing out the edges. My little 12 ton shop press started the forming process, but eventually I had to take it into work and push it with their 35 ton press to get all the detail. Here's how it looked when I got it pressed.
Then I needed to bend it to fit the Vee, so I welded a piece of 2x2 inch angle iron to a short piece of 1-inch pipe to use for a press brake. The angle iron comes with a nice radius on the edges, rather than sharp corners. I put a big piece of rubber pad under the brass part and slowly built up the pressure until I got about the right angle. If you don't have a brake at home, this seems to be a pretty easy way to make one. I tried bending some 16 gauge (.060") steel with it - no problem.
I also got the ribs back from the local sheet metal shop. They used their big press brake to form some 26 gauge (.016") steel sheet into a tight U, put in a 3/16-inch steel rod, and pinched around the rod, then pulled the rod out. That left a round bead on the edge and a 1-inch deep web to keep the ribs stiff. Once I get ribs welded in, and the last of the lumps and bumps out of the shell, then it can go to plating. The rosette will get plated separately and get attached with some studs that I'll hard solder to the back side.
Now, has anyone got a nice 1.25-inch diameter grille badge from the circa 1930 period that looks like the one at the top of the page? There a many larger ones on Ebay, but I can't find a small one in good shape.
And while you are shaking your head as you read this, remember: Anything worth doing is worth overdoing!
We've got to quit saying, 
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