To Blast or to Dip: The Classic Car Restoration Dilemma
To blast or to dip a classic car is a topic that is often hotly debated despite the fact that the decision is rather straight- forward if you have your facts in order and know the condition of your car. Many people get lost in this particular argument thinking it's a matter of opinion, but when you know the benefits and flaws of each method it's easy to see that the issue is more about science - and your budget - than it is about personal preference.
First, let's examine the negative aspects of media blasting and chemical dipping:
Primary Reason Not to Chemical Dip
A chemical dip will remove everything from the body of your classic car; not just the paint. Dipping the car means that you'll lose everything including seals, gaskets, adhesives, filler, bondo, underseal and antiflutter in addition to nearly complete removal of rust. This means that some cars once dipped are impossible to return to their exact factory specifications; a discrediting move in some show and club circuits. For cars with only light rust, this option is likely to be overkill.
Additional Chemical Dip Drawbacks:
*Dipping is expensive
*In most cases will require shipping to one of the country's few dipping facilities
*Welding and replacement of panels required
*Acid not washed away or neutralized or chemicals trapped in seams may quickly cause rust and paint bubbling
Primary Reason Not to Blast
The primary reason not to blast your classic car is that the media will never be able to penetrate all areas of the body, leaving rust behind that will quickly undermine even the best blasting job. This is true regardless of whether you choose sand blasting, soda blasting, or blasting with any other media like ground walnut shells.
Additional Blasting Drawbacks:
*Can easily lead to heat buildup and distortion of panels
*Takes a long time to do correctly
*Media can become trapped in areas that are impossible to clean, leading to early body compromise
When to Dip
If the body of your classic car is moderately or heavily rusted, or if you need to strip the entire body down to nothing, a chemical dip is not only the best option; it is the only option, as blasting cannot accomplish this task. A chemical dip will work its way into areas that media simply cannot reach, ensuring that even "invisible" seams, channels, nooks and crannies will be penetrated.
Additionally, a chemical dip combined with a zinc dip, electrophoretic E-coat or a similar process uses electricity to positively charge the body of the car while negatively charging the primer, allowing for both chemical and molecular bonding that cannot be achieved using any other method.
When to Blast
If your classic car has only light rust or you only need specific parts or panels stripped, blasting may be the best option although it is not the most thorough one. If you need to ensure that only the paint is removed from the body and panels, then blasting is the only option when compared to chemical dipping.
Of course, if you don't have the rather large budget required for a full chemical dip, then blasting is your best and most efficient choice...unless you intend to attempt the project the old fashioned way; by hand.
Important note for both methods: it's critical to remember that once bare metal has been exposed on your car, it must be immediately treated or it will flash-rust. Stripping a car or a part bare and returning to work on it later without protecting the metal first will result in disaster every time, as many exposed surfaces will rust in 24 hours or less.
About the author:
Jim Davis is the founder of Zero Tolerance Restorations in Oakland Park, Florida and is a passionate collector - and restorer - of 1953-1967 classic Corvettes.
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