A Layman's Guide to Restoration Part 4
Strip the Paint
by David Grainger
President, The Guild of Automotive Restorers
So you have to strip the paint off your car. Oh that's easy, bring in the sandblaster and in minutes there won't be a shred of paint left on the car. Unfortunately after sandblasting your chances of having a single useable body panel is about as remote as the chances of the proverbial snowball. Sandblasting is fine for removing paint from heavy metal parts and is irreplaceable for stripping frames and running gear, but it should never ever be used to remove paint from body panels, and although it can be used in a limited fashion on rusted areas of rockers and fender and quarter bottoms where metal replacement is required, you should never blast a large part like a hood or trunk or any large flat expanse. Sandblasting builds up a lot of heat in a very small area that leads to the metal expanding which then causes warping. Not a good idea when the point of the exercise is to make it flat and smooth.
Now there is a newer process called soda blasting which I have not used but which others have assured me does not build up heat and cause warping. Another method is walnut shell blasting which is also gentle but removes paint quite well.
Another stripping process is dipping which not only removes paint but also seeks out and dissolves rust. This is a very efficient method of stripping but it has one huge drawback whose effects I have seen on more than one occasion.
It removes paint and primers from all over the car including areas that are impossible to get paint into later. Despite the dippers' best efforts to neutralize their chemicals, it seems that there is often a little hiding in some crack or crevice that will rear its head after the fresh paint has gone on. Also when water gets to some of those areas which paint couldn't get into, the result is a car that bleeds rust onto the ground whenever it rains. This I have learned from personal experience. Chemical dipping is very efficient but it is best done on non-complex panels that have no seams or nooks and crannies for the chemical to hide in. A fender is usually O.K. but doorframe assemblies often spell trouble.
If you want to save the most amount of money and don't mind getting a little dirty then hand stripping the car will be your best bet.
There are a couple of ways to do this depending on the paint that is on your car.
If your car has been painted in lacquer then you can often strip the entire car using just a razor blade in a quality blade holder. This sounds like a monumental task but it is rather fun if the paint is brittle and a trunk lid will strip in five or ten minutes. Wear eye protection as the shards are very sharp and fly quite a distance. Razor blading will usually remove the paint but leave the old red oxide primer. The primer will rarely strip this way but it will sand off very quickly with a good sander or feather edger and this will also prepare the bare metal for the initial priming later.
Be warned, a sharp putty knife won't usually strip as fast as a razor blade and a dull razor blade also won't strip well. You need a sharp blade to get under the paint and you will have to attack it from a very low angle. A good holder will aid you in maintaining the right angle to remove the paint.
One thing that you may notice is that the paint chips start to load up around the base of the razor blade where it is held in the holder. When this occurs the blade develops a slight curve and will start catching and gouging. It may also shatter the razor blade, which can be dangerous. Keep the chips from building up by sliding the blade in and out of the holder when you notice them piling up. If your paint won't blade off un-aided, then it is time for some chemical assistance.
Most good quality paint strippers are available from your local hardware store or automotive paint jobber. Here is a small tip. The stripper you get from the jobber will often cost three times more than the stripper from the hardware and will work no better or worse so go to the hardware first.
Some strippers are brushed on but I prefer the ones that you spray on. These usually come with their own spray bottle but rarely will the one bottle get you all the way through the job before it fails. Stock up on a few extras so that when you keep pumping and nothing happens you can change bottles. The key to preserving the bottle for as long as possible is to empty it after using and fill it with warm water, giving it a few pumps to clean the tip. Some strippers lose their potency when left in the pump bottle so you will also save money by dumping unused stripper back into its tin. If the stripper that you purchased is brush on there is a secret to the way that you brush it onto the paint surface. Load the brush or pour stripper directly onto the paint and then start brushing but don't brush forward and then backwards through the stripper. Only brush in one direction. Dragging the brush back through the stripper will lift paint particles into the chemical and will reduce its effectiveness.
Allow the stripper enough time to bite in and then using a razor or a very sharp putty knife you can scrape off the paint. You won't get it all the first time around. It usually comes off in the order it went on and don't dig at it or you may make gouges in the metal which will have to be repaired later on.
Avoid getting the stripper on your skin. If you do get in contact with it you'll know. Keep some water around just in case you need to wash it off quickly and always wear eye protection. Remember that the stripper is just as happy taking the paint off the garage floor or your wife's car so make sure that you do it in an area cleared of possible hazards. You should also keep all the doors and windows open if you are doing it in the garage. I don't think the fumes are very good for you and I would imagine that your family wouldn't be too happy about the aroma permeating the rest of the house.
Once you have removed the lion's share of the paint it will be time to start sanding. Don't worry about taking every last bit of paint off the car with the stripper. It will be a lot faster to get the last remnants off with a sander. Areas around windows should be carefully scraped and hand sanded to avoid damage to the glass and rubber if you are leaving the windows in. These areas will present a challenge but make sure all of the paint is off. You must also make sure that there is no residual stripper left on the car which can come back to haunt you later.
Sanding the car to bare metal is your next step. Eighty grit is the fastest way to set up the surface for what comes next. In the next installment I'll go over the dos and don'ts of sanding your car's tender skin.