Morris Minor Owners Club

Having not given any treatment to the underside of my car since owning it (7 yrs!) I am well aware that I should probably waxoyl it. I have been lazy on this front as it is coated with a thick layer of mud and oil which appears to have given it a thick sealing coat.

What is the standard protocol for protecting the underside? Can I simply lift the car on axle stands and coat the bottom in Waxoyl, or should I scrape off all the muck there currently and seal the base surface?

A friend told me to use 50/50 sump oil and diesel, any thoughts on this? Or would Bodyschultz/underseal/waxoyl be better?

Would be interested to hear any advice on the issue.

Cheers
George

Getting Waxoyl etc. inside the box sections will do more to protect the structure.
With the gearbox cover off you can do the front chassis legs.

Much of the dirt on the underside may contain salt, and even if it doesn't it will tend to stay damp once wet.
I'd say clean it off rather than cover it up.

Engine oil and diesel would smell bad but should seep into all the nooks and crannies.

Use a parafin gun attached to a compressor... really really warm up the waxoyl until it is really runny. I heated the parafin gun attachment pot in a pan of water on the stove. Then just blast it into the box sections!!! It'll solidify almost as soon as it hits the panels.

Thanks for the replies chaps. Damn! I was hoping not to have to get under there and scrape it all off, but like you say MarkyB, it will probably contain lots of salt from trips to the coast and also stay damp when wet. So it appears thats the way to go. Oh for a hydraulic lift to make access for scraping easier!!

Does anyone have any opinion on Waxoyl vs Dinitrol Corromax?

Do you have a local garage with a jet wash?
I'd take it there and give it a couple of cycles of pressurised water underneath.
Think about where the mud traps are (over the headlights, back edge of front wings and the place where the rear axle mounts to the springs) and give them extra attention.
Wear suitable clothing, sou'wester? and have at it.

This job would be better done in summer when things will dry out faster and what ever treatment you use will tend to seep rather than solidify.
Still worth giving it a good clean though.

GeorgeHurst wrote: Does anyone have any opinion on Waxoyl vs Dinitrol Corromax?

I have no preference, but I used clear waxoyl. Unless you have any particular favourite, go for the one you can get the best deal on. I bought a 5 litre tin from Halfords, I put it down the internals such as, down the chassis legs, front chassis section, side sills, inside the rear arches where the wing captivated bolts are, the channels inside the boot, down the box section under the rear seat, inside the doors, and the spring hangers. I cleaned the external exposed underneath and painted with POR rust paint, so didn't waxoyl. I still have a bit of waxoyl left to rub places with a paint brush. It took an age, but if I keep on top of it, it should last..... he says!

Take your time, do a section at a time, it isn't such a chore then.

We've got a decent pressure washer at home, so I can give it a go with that
When I rebuilt the car after respray I gave a good coat of bodyschultz to all the wings and also the the floor pan of the interior / under the rear seat so hopefully they are all safe and sound, but neglected to do the actual underside of the car or inside any box sections. Perhaps better waiting till better weather like you mention MarkyB, and maybe I can use the meantime to find a pit or a lift I can borrow for a day or two.

Thanks for the advice

I was fortunate enough to start with a solid clean car freshly painted top and bottom. I used clear waxoyl rather than the black 'underbody' stuff to paint the underside for the simple reason that if I had not been thorough enough or corrosion was starting from the top side of the panels or in the cavities then it would be easy to spot before it spread. My previous car had severe corrosion which was almost totally hidden by underseal.

Good thinking Peetee, hadn't thought of it like that. Good idea.

I like things to be uniform, so would probably want to paint the underside a uniform colour if I were to use a clear underseal. Would POR15 Metal Ready, to dissolve existing corrosion and prepare the metal, followed by a coat of paint and then a clear underseal be a suitable way to go do you think?

Hi George, I used dinitrol applied with a brush on my trav's bottom and dynax S50 for the internal metal work.In over 20 years of restoration I have tried every product out there and these two are the best IMHO.
Old engine oil if applied regularly comes a close second for preservation.
I found waxoyl tends to dry out and crack which concentrates moisture into localised areas.

i pressure wash all the underside and arches every year at about september time then after a few days drying i spread 5 litres of black waxoil around with an old HVLP electric spraygun

Thanks for that guys, I've got a compressor and a pressure washer so should be set to go. Going to see if I can borrow a car lift off someone to make it a bit easier!