Preslee Jeffers owns Action Metal Stripping in Hubbard, Ore., and he took some time to chat with us about stripping cars for restoration:
PR: Can you give us a rundown on the stripping process?
PJ: First of all, you have to tear the car down -take the doors off, take the hood off, because youíll get a better clean that way. Take out all the upholstery, glass, chrome and wiring. Take all the aluminum off, because the caustic used for dipping will dissolve aluminum. You have to tear a car all the way down to the shell,
PR: So absolutely everything has to come off?
PJ: Yes. Be sure to take the VIN tag off, because those are usually aluminum and you donít want to lose that. You may want to engrave the VIN on the body, if youíre concerned about it.
PR: What happens once someone brings you the shell?
PJ: Then it depends on what you want. Some people like chemical stripping and some people donít. The downside of chemical stripping is that the chemical can get trapped in the pinch welds and leak out 6 months to a year later. The chemical dries up, but when moisture gets to it, it reactivates. A lot of people will bend the pinch welds back so they can clean them out, or theyíll remove the skins from the structures entirely and reinstall them afterwards.
PR: Whatís involved in chemical stripping?
PJ: The dip solution is a caustic soda. Itís an alkaline called sodium hydroxide. We heat it and it removes paint, grease, oil, and undercoatings, but it wonít remove rust. So you have to put the car in a bath of muriatic acid to remove the rust, then you pull it out of the acid, steam clean it, and put it back in the caustic to neutralize the acid.
PR: But chemical dipping doesnít work on aluminum, right?
PJ: If you put aluminum in caustic dip, itís guaranteed not to be there when youíre done. Aluminum is a very soft material. We have a chemical strictly for aluminum, called methylene chloride. Itís not a caustic and itís not an acid. Itís a solvent-based product that removes paint, powder coat, grease, whatever. Some cars are particular problems. For example, on Austin-Healeys the skins are aluminum, but the frames are steel, so itís a challenge because the methylene chloride will make steel rust.
PR: Tell me about media blasting.
PJ: With media blasting, we use plastic, glass, walnut shell, or sand. Plastic works great for removing the paint, but wonít remove rust at all. Glass will remove the paint and surface rust. Sand will remove everything, but itís very aggressive and will have a chance of warping panels. Sandís the worst.
PR: But there are parts of cars that shouldnít be blasted, right?
PJ: The metal skins on doors and hoods are thin, and thereís not much bracing behind them. Theyíll warp if you blast them. We donít use sand on surface body panels, roofs, hoods, or trunk lids. We dip the doors, hood, fenders, then go over it with a really light blast afterwards. For a chassis, weíll sandblast it. Weíll also use sand for brakes, suspension pieces, and other parts that are made of cast steel.
PR: Which process is better?
PJ: People like chemical stripping because it leaves a nice a finish, and thereís very little metal loss. But they donít like chemical being trapped in pinch welds and inside of box sections like rocker panels. But with any type of abrasive blasting, thereís a dust issue. Thereís always a little bit of material left in gaps, spaces, and box sections. Itís up to the customer which one they prefer.
PR: What should someone do with a car once youíve stripped it?
PJ: You need to seal the metal immediately after stripping. Itís not so bad in the summertime when itís dry, but if itís wet, you need to get it to the body and paint shop ideally the same day. We get on the phone with the customer as weíre finishing up, so they can get the car right in to be primed, sealed, or painted in some manner.
PR: How much is this likely to cost?
PJ: That depends on the size of the job, really. People should always compare prices between vendors. When weíre blasting, we charge by the hour and we know how long it takes to blast a particular size of car. Chemical stripping is always the most expensive. To get a body chemical-dipped, youíll pay 2 to 3 times as much as to blast it.
PR: How should someone evaluate a blasting or stripping shop?
PJ: In our business, it goes by reputation. Car guys can join a club if they donít know people who have done restorations. If someone is talking from experience, theyíll be able to tell you where to go. If you donít have that, ask a business for references.
PR: Anything else to add?
PJ: Always get your estimate in writing, because sometimes you go to pick up the car and it wonít be the same price as when you dropped it off. You donít want to be surprised at the end.