Body Panel Underseal

[Faheem]

Hey guys,

I'm looking at starting to prepare the zed for a respray as I have had all the bits required ready for some time now.

I picked up some wide body rear wings and a rear bumper from a 2.8 in October last year. Believe it or not it was a 180 mile trip up to pick them up from @Davyhoogy and bring them back in the Polo!

The panels are in fair condition with some small dents and a few scratches. The main selling point for me was that there was almost no rust on the panels which is very rare for a 20 year old body panel.

As there is minor bubbling on the rear of the panel the idea was to sand it back and coat the rear side of the panel with a rust converter and then a top coat.

Can anyone recommend what to use?

I was thinking of using some rust converter and then spraying cold galv over it.

I've used POR 15 for my subframe refurb but don't fancy using it for the underside of the panels.

 

[gookah]

Many people would only use stuff with a chemical sounding name nowadays, there are all sorts of wondrous snake oils to be had.
POR 15 was batted around at one time as the all encompassing treatment of choice, but is recently being reported more so to actually be POoR

Myself, I would use hammerite, underseal or waxoyl.
Old school, but has worked for people for many years.

 

[Mazza]

For rust treatment on the rear of the panels and rusty bits I have used these.
After wire brushing,
Rustins Rust converter, Fortress grey undercoat and Hammerite smooth Black as a top coat.

Just with rust converter.

Finished

Seems to work on ok

 

[DrWong]

When I did my chassis sills, I used Bilt Hamber deox citric acid gel to remove literally all traces of rust. I then sealed the bare metal with Lechlar epoxy primer which is water proof unlike normal primers. The citric acid gel takes a bit longer as you have to apply, wait a few days and then scrub off. But it really does get rid of all the rot and leaves lovely shiny metal behind (albeit pitted). I worked on the basis that if I could get at the rust with a converter, I may as well just use a rust remover and get rid of it.

My sill thread: https://zroadster.org/threads/chassis-sill-refresh-or-lessons-in-optimism-bias.26071/

I went from this:

To this: