Another Year, Another Derby

Charlie has 7 more years until he's a Cub Scout. I can't wait that long. Here's year two in my quest for perfection in The Pinewood Derby.

Last year was a 1973 BMW 2002. This year it was the 2001 Audi TT coupe.

1. Pattern. Last year I had to take measurements from an actual car then draw the car to scale from all angles. This year I lucked out an found some CAD drawings on the web.

2. Wells. You can't cut the wheel wells from the car after it is assembled so you have to cut them first then add them to the sides of the main body of wood. Smooth them with a round edged file after cutting them on a scroll saw.

3. Glue. Use wood glue to join the main car body (the block of wood that comes with the Pinewood Derby kit) to the fenders you just made. To avoid seams in the final car sand or plane the surfaces flat, apply wood glue and clamp together with a good amount of pressure. (I didn't have clamps so I stood on my car for 15 minutes.)

4. Shape. Cut the roof from a separate block using its own pattern. Then do a lot of shaping. My scroll saw isn't big enough to fit around a lot of these parts so my belt sander was my main tool for shaping.

5. Smooth. Use 150 grit sand paper for subtle contours and to smooth out the bumps. I used a file for the lines in the hood.

6. Prime. This is a key step. Wood is very porous and soaks up paint so it dries ugly. To avoid this use multiple coats of primer. I used a small can of grey primer for model cars I got at a hobby shop for model cars.

7. Paint. I haven't perfected this yet, but if you were pretty thorough with the primer your car shouldn't need more than a couple coats of paint. Again, this was just a small can of hobby spray paint. Be careful not to spray to much with one pass or it will run. Give it a coat then repeat after a few minutes.

8. Decals. I drew these with Microsoft PowerPoint. That's not what it was designed for, but it works. I printed them on to normal paper, covered with clear shipping tape (to make the decals glossy) then fixed them to the car with doublesided tape. This method worked well for last year's BMW which had modely flat surfaces. The Audi is very rounded so many of the decals wrinkled when I tried to make them conform to the curved car body. I need to figure out something better next year.

9. Seams. Using electrical tape for the thin black stripes turned out great. I just cut the tape into strips with a razor blade (Exacto knife). I didn't finish the door seams or hood because we were running late to the derby.

10. Wheels. Like last year I just used silver lacquer paint and a small brush for the wheels. Nothing fancy, but it has a nice effect.

11. Race. Here we have last year's BMW, the Audi and a local Boy Scout's police car. The police car toasted us.


My friend Adam goes all out on the wheels painting the letters on the wheels and making sure only the spokes are painted and not the relief area between the spokes. I'm not as meticulous. He also put lights in his car. Very impressive. I'll have to copy that next year.