Underbody Protection

[PGH]

The underside of my Morris is in good nick but only coated in chassis black. The previous owner spent a long time getting the old underseal off before applying chassis black. He told me that he didn't like waxoyl etc and believed that the chassis will be protected with the coating he applied.

My initial thought was to give further protection by using Bilt Hamber for the box sections and Dinitrol 4941 for the underside. Is this wise or should I stick to the chassis black and recoat for extra protection?

[cadetchris]

if its in good nick underneath and paint is doing the job well, i would stick with that. i would definitely go nuts with waxoyl in the box sections

[MarkyB]

Seconded, I'd be tempted to paint some on spot welded seams too, in the hope that some will seep in between the two parts like water will.

[beero]

If you get any rust it will show by flaking off the chassis black so it is better than underseal which just keeps the rust hidden. You can paint waxoyl or similar onto the chassis black and it will just make it matt when dry. I also second the suggestion to spray the cavities. You will have to keep an eye on areas that get stone chips and top up the chassis black occasionally in these areas.

[chickenjohn]

If you get any rust it will show by flaking off the chassis black so it is better than underseal which just keeps the rust hidden. You can paint waxoyl or similar onto the chassis black and it will just make it matt when dry. I also second the suggestion to spray the cavities. You will have to keep an eye on areas that get stone chips and top up the chassis black occasionally in these areas.

I absolutely agree with Beero's philosophy on underbody protection. Chassis black and waxoyl is the way to go and regular maintainance- far better than relying on underseal! When welding in new sections though, it is a good idea to use seam sealer to protect welded seams and overlaps, and in high impact areas, anti stone chip paint helps as well.

[moggyadventurer]

Hi,

Underbody protection is dependent to how you wish to use you car. If using everyday, then an underseal like dinitrol or the many others on the market are a good idea if checked regularly. However there is nothing nicer than clean black paint on the underside. Its a difficult decision really. If you are using it primarily for spring/ summer driving, just touch it up as an when required - it does look better. However you may consider a clear wayoyl if using for winter? It washes off quite easy and canbe reapplied.

[chickenjohn]

Moggy adverturer- thats another valid underbody protection philosophy.

It is all about keeping air and water (and salt in the winter!) away from the underside of your car to stop if rusting. If the car is going to be used in the dry - mostly summer use- and only exposed to the odd summer shower by accident- then yes, chassis black over a decent anti rust primer (zinc) is perfect for that use and keeps the show car shiny underneath as well as on top!

I would still use cavity wax in the sills and box sections though, and use seam sealer to seal any seams and welds underneath the chassis black paint.

[PGH]

Car will not be used in winter months so looks like chassis black and waxoyl or similar in the box sections. Thanks