Q: Ron, as I'm sure you have heard many times, your column is the first thing I read, I just wish they would give you a lot more space. I've been a body man on and off since my teens; I'm 59 now. I'm sending these pictures to ask how you would go about repairing this door. You would be doing a great service to many people, since I have seen very few doors like this that weren't cracked. I know that sometimes it's hard to repair something that the manufacturer apparently didn't get right, but any help would be greatly appreciated.

Kim Groth
Via the Internet

A: I'm very glad that you enjoy the column. It's pretty easy to see why these doors crack where they do. The doorskin and inner panel have a vertical flange along the window opening, and that flange strengthens the edge considerably. The top of the door toward the front of the vehicle has a wide horizontal flange, strengthened even more by another vertical flange. Unfortunately, the flanges end at the window channel, and this creates a weak point. I believe your question is more about how to strengthen the door to prevent this from recurring in the future, rather than just repairing the damage that's there.

A very straightforward way to strengthen that area is to install a “doubler” inside the door. You can make the doubler by cutting a U-shaped piece from steel plate about 3/16-inch thick (I've added an illustration of a doubler to your photo). The details of how the doubler is joined to the door will determine how long your repair will last. The key to making it durable is to spread the strength of the doubler over a large area. If your doubler is too short, it won't be long until you get new cracking at the ends. I'd recommend making the legs of this doubler about 6 inches long, with the solid front section around 3 inches long. Avoid having square corners on the insides of the legs; notice the broad radius I've shown in the photo.

Since it's virtually impossible to get inside the door to weld this doubler into place, I'd suggest drilling several holes along the top edge of the door, and plug-weld the doubler, which will ease the job considerably! I hope this makes sense, but contact me again if any of the details are "fuzzy".

Q: I have run into a snag restoring my 1973 Vega. The front bumper has been hit, and is in relatively good shape except for one place that has a wave in it where it's buckled up about 3/8-inch higher than the rest of the bumper. The metal is so thick that I wouldn't think a hammer and dolly would work. I thought about using a press to bring it back into shape. Do you have any ideas on how to straighten this bumper back out?

Lee Torode
Via the Internet

A: Yes, you can straighten bumpers with hammers, but it will probably take a very heavy hammer to make the metal move. A press can be used, too, but hammers and dollies are sometimes better, since the dolly will help to control what moves and what doesn't. If you use a press to force a 3/8-inch high spot down, you may get two 3/8-inch low spots on either side. Using a heavy hammer and dolly will allow you to pinpoint where the metal moves and where it doesn't. One benefit to working on bumpers is that there is plenty of material thickness, which allows you to do some heavy sanding or filing to get everything smooth after you finish your hammer work.

You can e-mail your questions to Professor Hammer at covell@cruzio.com or send mail to Professor Hammer c/o STREET RODDER, 1733 Alton Pkwy., Ste. 100, Irvince, CA 92606; you'll receive a personal reply. Ron Covell has made many DVDs on metalworking, and offers an ongoing series of workshops across the nation. Check them out online at www.covell.biz, or call for a current schedule of workshops and a free catalog of DVDs. Phone (800) 747-4631 or (831) 768-0705. You can also send a request by mail to Covell Creative Metalworking, 106 Airport Blvd., #105, Freedom, CA 95019.