Undercoating Suggestions..., Wurth SKS...POR15...Paint??? Options

[ty914]

Finally some progress is being made here. I have the undercoating almost gone. Surprise no rust!!! So here is the question…what to do with it now? I was planning on spraying it with Wurth SKS. I do not plan on making the underside perfect so is this the best option? I just spent a week on my back to just put it back on? So what have you done to your underside? Pictures and lessons learned please…

[Katmanken]

I'd put a coat of 2 part catalyzed primer on it first. Dupont Variprime is a great self etching 2 part catalyzed primer. Sets up hard, can be stored in a sealed jar mixed for a couple of weeks without hardening, and has some zinc for protection.

Then I 'd add the undercoating.

Why? Not much sticks to bare metal well except primers and unlike most primers, variprime is NOT POROUS.

Second, get a nick or stone chip in the undercoating and water can wick up and cause rust to form on bare metal. Unprotected metal rusts WAY faster than protected metal. And, if the undercoating doesn't stick well to the bare metal, it will seperate easier and the rust will spread quickly from water wicking betweent he undercoating and bare metal.

So, I like the Variprime for a good hardened basic waterproof rust protection coat and primer combo, and the Wurth (or equivalent) undercoating to act as a shock absorber for the rocks and sand that will try to blast the paint off the bottom of the car.

Do what you want. They aren't making any more teeners.

Oh yeah, Variprime must be sprayed, doesn't brush well.

Ken