Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Corrosion

Hi all, hope you've had great Christmases.

After just 10 months and 1750 miles, the bottom dome-headed nuts attaching the luggage rack, were corroded. I've dealt with that (wire wheel and aerosol hammerite). I can't find any other corrosion, but I haven't yet raised the car to look underneath.

So, got me wondering: are there any other known rust/corrosion areas on these CX cars that I should give some preventative care?

Thanks,
Martin

Hi Martin, There is plenty you can protect underneath and so it's well worth getting your car up in the air and applying your favourite wax. I am now using Bilt Hamber Dynax UC wax. Fantastic product that when sprayed on fine gives an almost smell free, dry touch, wax coating that does not come off easily. I used it on everything, alloy chassis and all linkages. If you get any over spray on the paintwork have fun trying to get it off. Thoroughly recommend.

Thanks for the reply. I used Dinitrol underbody wax everywhere underneath my TR3A. Wheels off, polythene taped over the brakes! A black waxy substance. It was a steel construction and the coating was pretty good for the last 10 years. But it never dried off, doing anything under the car was always an old overalls job and the stuff still got everywhere. I've used some Bilt Hamber cleaning products and been very impressed. I will order the Dynax UC and see how that dries off.

So, do you recommend coating the aluminium underside? Is it a full wheel arches etc. job? I'd hoped all that aluminium showing was all either corrosion resistant, or appropriately coated at the factory?

Regards, Martin

I've used dinitrol also. Great stuff with various types of gloop. I wanted as clear finish as possible for the alloy chassis so I could still see it. The Dynax was perfect for that purpose. The alloy on my Plus Four is untreated from what I could see. I did note though at first service some black inhibitor was applied to various parts underneath which I think was a Morgan initiative. The Dynax dries off really well I found, you can scrape it with a finger nail but you won't wipe it off. Spraying it warm is very helpful and I put it everywhere underneath. I don't ever want to see any brown metal wood worm under there.

I agree with Landy, keep it clear on aluminium. I've favoured Tectyl 506 for 20 years, now called Tectyl Amber, because it comes in big tins for brushing, but also aerosols, it's pleasant to apply, stays very slightly waxy but is OK to work around.

After a bit of research, the recommended Bilt Hamber wax looks good. I've ordered the Bilt Hamber Dynax UC, along with their Surfex HD cleaner, to prep the underside. Thanks for the advice, Martin

Hi all,

You can get a clear dynatrol and dynatrol is an excellent product. I get the black everywhere thing, that's not pleasant when working on the car but it is better than corrosion or even real rust damage. "It doesn't seem to dry out". Well that's good and as it's meant to be. If it dried out it would lose the self repair element of the product... It has a tendency to creep with temperature changes and re-cover small areas or scratches.

If I were presented with a CX or later car for corrosion prevention treatment I would first spray on. ACF-50. Slightly warmed or on a hot day it sprays like water and over a few days dries to a fully dry finish but whilst wet creeps into all those seams and difficult areas and leaves a slightly purple translucent finish. This colour is a trace element put into the product to show successful cover on inspection. In my younger days when flying this was used in aircraft structures to prevent hidden corrosion and prevent failure from unseen corrosion especially where riveted structures could hide it. Oh! and it will not wash off or away as only grinding it off will remove it! You can then, if you like, use a wax system on top of that, Why you ask, Well the exposed areas that are subject to road debris damage can in effect damage the ACE-50 finish penetrating it and exposing the open alloy surface thus creating micro areas that can start to corrode and as we know alloy is great at allowing corrosive creep beneath any protective surface through the way it corrodes...... ask the Land Rover guys! The self repair ability of the wax product with the designed in creep help prevent this. Now When I apply my wax of choice using this technique I thin the product down by at least a 1/3 with white spirit and I then do an annual check at service to make sure all is well. About every 3-4 years you can see the product starts to dry to some extent and when this happens I then reapply a coat of the product thinned to 50/50. This makes it easy to apply and way less messy. This is in order to re-soften the product and flat it as it promotes the re-creep ability.

I have a plus 4 classic and mine left the factory with the black everywhere applied by Morgan. So for my car I have continued to use the top up system using Dynatrol 50\50 warmed with white spirit, Dynatrol is the product used by Morgan. If you use ACE-50 in areas that are not subject to abrasive type problems then I would rather not use wax products on top as the surface is totally inspectable and is really in effect protected in the best way you could possibly choose.

Many people think that ACF-50 was designed for the motor bike industry, Not so, they just cottoned on to it first and it was in fact designed for aviation use. If I could only have one product it would be this one!

Thanks,

I like the suggestion of a prior coat of ACF50, allowed to settle and dry a bit. I use ACF50 on my old motorbikes. It's easy to apply, I find the spray a bit thick, so lightly wipe on with a cloth. But it does wash off after a couple of washes and, as you say, I'm pretty sure wouldn't survive long exposure underneath without regular reapplication.

I hadn't thought about applying it first. I will do a small area first, then dry it and check how the UC wax adheres. Nor had I thought about warming the ACF50 up. I will try that, to see if I get improved creep into seams and rivets.

At the moment I'm working through giving the underside a really good clean in readiness. With the cold snap, I'm only managing an hour at a time, even with a fan heater! Just nibbling away at it, but pleased with how clean it's coming up, no corrosion so far, apart from around one of the rear swingarm joints / bushes.

All finished. I extensively cleaned the underside and suspension, doing one wheel off at a time. I got it thoroughly dry, then ACF50'd bolt heads, rivets and rusty suspension bush caps. I also did the wheel nuts. Then I lightly sprayed with Dynax UC and gave a heavier coat to any seam areas and exposed bolt heads. Polythene shopping bags went over the brake discs and a clean with a microfibre cloth wetted with white spirit afterwards, just in case. I also removed the luggage rack and vented rear panel and gave the area beneath the same treatment. I probably won't bother with that in future.

Whilst the wheels were off, I gave them a deep clean and then gave 2 coats of a spray on ceramic coating + buffing, just to help reduce future cleaning effort.

Apart from the metal caps on the outer suspension bushes, everything looked good underneath, so far. Good to catch it with some protection, before any deterioration starts.

I was glad to finish it. Not an exciting job. In all, I'd estimate it took about 20 hours! Not something I'll do every year. I think, every other should be OK. I will also pick a warm autumn spell next time! Dynax UC is easy to use. I left each can in the house to keep warm, before spraying. I also had a fan heater on the area to be covered, prior to spraying. Went on nicely and sticks. It does feel good to have given it the best chance of avoiding future corrosion though. I guess time will tell.

Good old fashioned wax oil for me sprayed underneath and wings. We live on the coast the only bit of corrosion I have is one of the windscreen pillar's where the stainless bolt attaches. Now 6 years old and in commission in all weathers 12 months of the year.