The Mitsubishi Pajero Owners Club®

2.25diesel · Posted: Fri Aug 18, 2017 14:53 Post subject: Undersealing wheel arches?

I was wondering about paiting some underseal on the wheel arches of my Pajero before winter.

I have heard different opinions on this. Some say it is a bad idea as rust can form underneath it, and can get a lot worse before you notice it.

There is some sort of sealant there already, but it is starting to peel away in places. I was planning to give the acrches a good wash, pick away the loose bits and paint over the top of it.

I would be interested in what other members do for underbody protection.

Thanks for any replies.

Google · Sponsor

peteinchad · Posted: Fri Aug 18, 2017 17:19 Post subject:

Every second summer I do the following:

I go to an HGV testing station and pay them £25 to steam clean the underside.
I then spend a day (or two) with a scraper and wire brush cleaning off any loose rust .
I spray any areas of rust with Dinitrol rust converter.
The cavities then get sprayed with Dinitrol cavity wax.
Then Dinitrol underbody wax goes on the floor and chassis.

I do the wheelarches with "Finnigans Underbody seal with Wayoxyl" (from Halfords) as it is tougher for areas that get a lot of water spray off the wheels.

You need to remove all the loose stuff that is already there - otherwise there will be pockets for water to get trapped in.

2.25diesel · Posted: Sun Aug 20, 2017 18:49 Post subject:

Thanks for the reply. Yours looks really clean underneath.

How do you get to the top of the chassis rails?

peteinchad · Posted: Sun Aug 20, 2017 19:22 Post subject:

tuk95m · Posted: Mon Aug 21, 2017 8:46 Post subject:

I sand blasted the underneath of mine, very messy but it does shift any loose rust, then after blowing off any sand out of the nooks and crannies with airline I painted with hammerite, then sprayed over the top of that with Shultz chassis paint. Used a small long reach roller for painting top of chassis rails and other parts I couldn't reach with paint brush!

John Pierre · Posted: Wed Aug 23, 2017 2:12 Post subject:

a good interim thing to do until you decide... slightly cheaper option (good if your not off roading it too) is it to treat it with ACF 50 corrosion protection and inhibitor.

it neutralizes rust and forms a layer of protection underneath. then when you decide to clean it up and do a wax oil etc it has loosened off the layers of rust.