For some a crazy question, but not for me. Would power washing my C 3 undercarriage then applying a sealer or some kind of protective coating be advisable? Would it add or take away from the value?
Thanks

 

To me it would depend on the quality of the sealer and the quality of its application.

 

Welcome to the forum!

That depends. If you’ve got the last ever 1971 LS-6 that’s incredibly original and worth well into the 6 figures putting undercoating on it will definitely take away from its value. On the other hand if you’ve got a 1979 L48 automatic with 100k miles it might actually increase. Of course you would want to do as good of a job putting it on regardless.

 

Do you plan on keeping it? If so & it's not super nice original why not.

But if you plan on selling it anytime in the near future doing that could be seen as covering stuff up...

 

I would not do it. If it has lasted this long without any type of undercarriage coating, it will probably last another 20 years or so. Especially since most of us don't drive them daily in snow and ice and salt anymore. And you most likely will be cleaning more often than the previous owners.

 

As others have responded, most responses will begin with “it depends”.

The juice may not be worth the squeeze. These cars have a full boxed frame so attempting to address internal corrosion by applying a sealer is futile. Same for the other notorious location - the birdcage. After 50 years, every ferrous part will be oxidized so unless you use something like POR to encapsulate the rust, most any other product’s effectiveness at slowing down the natural oxidation process is futile.

 

I'm going to dig a little deeper into the question.
First off, what would you be sealing the surfaces against and why is this a concern?Secondly, is your reasoning above a real concern for the way you use and store the car?We need more info on your situation and the current state of the car.

 

I'm in Florida so humidity is a big deal.90% for 6 or 7 months out of the year. I have no real concerns just want to preserve this as best as I can.

 

In your case I think paint alone will help considerably. Of course you could take it down to the bare frame and powder coat it like some people have done, but that’s a bit extreme.

 

As many people will tell you, I’m a little over the top about having a clean car.
I may even be a little OCD and I hate grease and grime.
I want the undercarriage of my cars, clean and I mean everything.
I would pressure wash every inch and component then paint what needs to been protected from rust but keep the fiberglass all uncoated.

 

I have one question - is the body still on the car?
If it is, I would never take a pressure washer to it, simply because as mentioned, you may not get to all the areas and/or the water will remain in many places for a while.
After we had owned our '78 for a few years we took it to a friend who had a shop and a lift, where we spent two full days cleaning off all the crud, grim and grease form the chassis and most of the suspension parts etc, by hand and without a washer of any kind. Amazingly, under all the filth, it came out looking really nice, most of it being still in factory paint in good condition.
BUT, we opted to use the friends built in spray system to apply what we in the rest of the world call underseal.😉. It seemed like a good idea until we came to do work on the car and found everything covered in black sticky stuff! Over the following 30 + years I have worked through most of the underneath of the car removing the underseal and re-painting where needed with Hammerite satin black paint. That protects it well, looks nice and is a whole lot nicer to work with and, keep clean when the car does get dirty on a weekend away etc.
Is ours as clean as OCB's.....? Errr NO😄😄 But we try!

 

You're 64. Just enjoy the car and retirement.

 

Ya thats more than I want to get involved with. Thanks

 

I always power wash and degrease a vehicle’s undercarriage. I also paint to protect exposed metal.
If or when you go to sell it can make a difference. Just like detailing an engine compartment.

 

I would use PB BLASTER under coating . It will protect frame from rust or use a spray under coating. Prep is the work if you have rust. I have used PB on a new vehicle and what it does is sheds salt and gives mice a hard time climbing because it never dries and leaves a sticky surface.