restoring undercarriage on lift?

[citadel]

Guys,

Are there any concerns doing a restoration and doing the underside of the car on a lift? Dont have a rotisserie. I have heard some say that doing a convertible on a lift is easier on the car body...? Any thoughts?
Do most guys strip off all the undercoating? My car has a very very light undercoating. Do some just paint the undercoating vs strip it all away?
What parts would you replace when doing the underbody? What underbody components do you paint or powder coat typically?

 

[dave5237]

Guys,

Are there any concerns doing a restoration and doing the underside of the car on a lift? Dont have a rotisserie. I have heard some say that doing a convertible on a lift is easier on the car body...? Any thoughts?
Do most guys strip off all the undercoating? My car has a very very light undercoating. Do some just paint the undercoating vs strip it all away?
What parts would you replace when doing the underbody? What underbody components do you paint or powder coat typically?

Hello. As far as the undercoating. I like to keep it on because it is extra protection on the undercarriage and I painted over mine to freshen it up.

 

[QTR MILE]

If the coating is lightly applied and not flaking off I would personally just power wash the chassis, allow it to dry and not paint it. Painting it looks fake and or like you just applied it to cover up Sin's in the floor. Just my opinion.

 

[wedgie]

I did mine on a lift. After stripping the interior, removing engine and trans, removing gas tank, lines and suspension, I used a propane torch, scraper and wire brush to remove all undercoating. A rag soaked on regular gasoline removed the residue. The now clean underside sure made replacing floor pan sections and installing frame connectors much easier. I then used "bedliner" on the bottom side. Holding up really well on my street drived Coronet.

 

[SirSixPack]

I just did the underside of my street driver Challenger. I removed the cruddy 40 year old factory undercoating and used 3M (spraycan 888) undercoat. It is not advised to paint over this undercoat, but this car is white and black anyhow, so a black undercoat looks just fine for as little of it anyone can see.

Tips: Don't spray when it's cool or humid. I did a section when it was and it did not stick well, and had to remove and start over. Also, as much as a pain as it is, compressed air out every nook and cranny & use acetone or other prep cleaner prior to undercoating.

Some people locally have been doing their rods and street musclecars with bedliner. Some guys like it because it's paintable but I have been told that there may be problems if you get a pinhole in bedliner it does not reseal as well as rubberized undercoating. If water gets in the pinhole it gets trapped and may make pits or holes.

 

[Propwash]

I removed all of mine, on my back with the car on stands...with a needle gun. Main reason, I wanted to see what it was hiding underneath. If you're gonna take the time and money to restore/refresh a car, why would you want to take the risk of issues down the road with rust showing its ugly face when you could have taken care of it when it was already apart for resto? Rust starts under paint, undercoating is no different. So, do you want to roll the dice or catch/stop it before it gets a chance?

Myself, I went down to clean shiney metal, coated with Rust bullet, scuffed, and then sprayed with SEM Rockit Truck bedliner. It is not paintable, but is tintable. With it being a Catalyst spray out of a gun and more of an epoxy resin, it is tougher than rubberized undercoating hands down. The factory undercoating was neither, but more of an asphalt based product. Either way...My 2 cents, I would get it off there to see what it may be hiding.

Good luck!

 

[70Fish]

FYI any original undercoating is prone to capturing moisture between it and the the steel so I'd remove it all and paint it body color or flat black.