I am getting my car treated with Lanoguard next week (2010 NC2). There are pros and cons with different methods but after research I am going with that then a yearly top up. Most of the factory underseal is sound and well stuck on, even if there is rust underneath the Lanoguard over the top will suffocate it so I don’t see any point in removing it.
My question is, the factory underseal on the rear sills is breaking up and showing signs of rust underneath - I know this is a well known problem area. Clearly it needs to come off here, but once it’s off what is the best thing to treat the bare metal in these vulnerable areas with?
Epoxy mastic paint like EM121 or Bilt Hamber
Upol Gravitex Plus
Some kind of zinc primer
Something else?
Ideally something that could then be sprayed with Lanoguard over the top for additional protection. Thanks
Needs cut out & fabricated first.
Nothing less.
Pointless spending hard earned wages on it until that’s done.
Rotting from the inside out.
Otherwise anything else is just a waste of money.
And Lanoguard is OK cosmetically for a few months but a lasting job needs modern stuffs.
I use Lanoguard for my garden tools before I hang them up for the winter…in my opinion it’s good for that and not much else. Opinions differ…
You would normally start by cleaning it back to see how bad it is first, if its not bad then use a rust remover (not converter) and re paint it, something like rustoleum combi colour is pretty good for this without going ott. Then apply your rust proofing.
Hard to see how bad it is.
I think it’s just flaking underseal and surface rust under, it feels completely solid so no need to remove the metal in that case. Lanoguard is modern, covering it in black tar underseal also has it’s downsides, that was not my question though. I was asking what the bare metal should be painted with to protect it.
That’s the exact spot I treated mine with the epoxy mastic. I first used a flap wheel to grind away any rust, it was only surface stuff then zinc primer under the epoxy mastic. I finished off, because the epoxy needs a coating over, with Dintrol underseal black.
Check annually for any nasties re appearing. I did my earlier 07 plate NC twice in those areas, it was a solid car underneath.
Wire wheel on an angle grinder, small hand wire brush and some rough sandpaper. Get it all as shiny as humanly possible. Prime with red oxide, which will act as a rust converter, rust proofer and primer. 2 coats of red oxide ideally. Top with underseal or bituminous paint, although because this is easy to reach I would use underseal, which is just a bituminous paint with lots of big soft particles in. The bitumen repels water and the big soft particles absorb stone hits and to some degree sound deaden the metal.
I used the Bilt Hamber epoxy, it said it needs a protective coat if exposed to sunlight etc… Ok not necessarily needed under the car but I did anyway, belt and braces.
The earlier NC I only painted over with Dintrol after grinding back any rust and using a rust converter. The rust started creeping through again after a couple of years so I went at it again grinding back then applied rust converter then the epoxy mastic then the Dintrol.
Sold that car after another year, all good underneath.
Bought another NC and treated that the same way (in the prone to rust areas) with the epoxy treatment etc. It was only around 6 months later I sold the car, all preventative stuff I done to it as I thought it was going to kept for a good while longer.
