[Fataero]

Hi guys, I have read a lot of threads related tot his topic but nothing exactly covering what I am contemplating. I have a '48 chevy that has never had any undercoating applied to the bottom. Consequently there are a few places where I will need to patch the metal but thankfully there are only a few. As I will be driving this car alot (I hope) I am seriously considering applying undercoating to the bottom of the car. I wouldn't be doing this to the chassis, just the underside of the body itself. The reason I am thinking about this is that I bought some rear fenders and an original gas tank recently that had been heavily undercoated. All of the areas with the undercoating had bright shiny metal underneath, while the non-coated areas were covered with surface rust. I cleaned the gas tank thoroughly and re-sprayed it with some Mar-hyde rubberized under coating. It looks fantastic, like a new tank. This car will never be a show car or trailer queen, I'm building it to drive so what do you think? Is this a viable option?

[50 chevy p/u]

It is definately a viable option.

I undercoated the underside of all the sheetmetal before I installed it.
So yes, go for it you have nothing to loose.

[oldred]

I would use a better undercoating such as 3M Body Shutz since there is a huge difference. Spray the Mar-Hyde on a spot and the 3M in another then after it has dried try to rub both of them off or hit them with a rag soaked with gas and you will find the 3M is a heck of a lot tougher. It costs quite a bit more but the cheap stuff will not hold up over time like the 3M.

[Fataero]

Thanks for the responses guys. I will check into the 3M stuff since I really do want it to be durable. As far as the actual spraying of the product goes, do you just lay on your back and go for it? Obviously there is masking involved. I guess I envision laying under the car on a creeper wearing a painter's hood, face mask and throw away clothes then just spraying away. I guess I will also need to put newspaper down on the floor. Anything else I need to be concerned about?

[oldred]

If you go with the body shutz you will need a gun but this can be found at Harbor freight for a fraction of the ridiculous prices most auto supplies or Eastwood asks for these things and the HR works just fine, I have used mine for years.
http://www.autotoolmart.com/cgi-bin/...1807&p_catid=0

[WmSteed]

Here is a little background on the why & where-fores of undercoating....
In the late forties and early fifties undercoating was sold by the new car dealers as an upgrade as were radio's, heaters, delux wheel covers, skirts, etc. I worked in and around new car dealers in the late '40's/50's and never saw a new car come in with factory applied undercoating.

Old cars that come from the areas that have wet nasty winters will generally have undercoating and generally speaking the body will be in desent shape, however, I have seen terrible rustout of body panels, under the undercoating.
A lot of the current car "restorers" like to spray undercoatings on their body repairs because they don't replace the rust out with metal, they use fiberglass mesh and rosin or something else, then cover the repair with undercoating to cover the areas up.

I am pretty perticular about keeping the undeside of my vehicles clean. I have found that paint is easy to keep clean and easy to spot in, whereas undercoat holds the road dirt and is difficult to remove so you have to respray the area to keep it fresh looking.

There is a place for both paint and undercoating, you just have to decide what works best for you.