Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Chassis care

First of all, I sincerely apologise to long-standing tm members who understandably get very bored when newer owners raise topics they have explored years ago. However I have searched on this topic without success and would appreciate some advice.
My car is 2012 and looks like it's had a hard life. Plenty of rust on the suspension and the chassis looks like it's been under sealed, and this is now failing.
Here's a picture- there are plenty of larger patches. I am thinking of re-undersealing the whole thing, and maybe squirting wax oil in several openings along its length. In the meantime I have sprayed ACF-50 on all the protruding fittings
Has anyone got better advice, please?

There are no silly questions we all learn from these posts.

Underseal can hide a myriad of issues. I use therefore clear waxoyl.

But as your chassis is undersealed already I would repair it by checking the galvanising is ok. If not repaint it with cold galvanising paint after rust treatment & then reseal it.

You should also oil the sealing rubber that are between the wings & the body. You will find posts on here about that.

Well you'll probably gets all sorts of advice but if it were mine I would thoroughly scrape off all the loose stuff, no point in putting anything on a flaky surface.

Once I'd cleaned as much as I could with a wire brush I'd use a rust treatment to stabilise things. I've used dinitrol rust treatment in an aerosol which seems good.

After that the flat chassis sections or outside you need to paint ior apply a wax coating to keep the nasty stuff away. Internal sections need a cavity wax and again I've used dinitrol but others are good too. Waxoyl isn't the most effective but better than nothing, loads of info if you google it. Stone chip is good inside arches or on sills etc but tends to flake and allow moisture to creep beghind it on chassis rails. Soft waxes are good and kind of self heal or are easily topped up annually.

But use a mask and dress with the right kit as I still have a pair of overalls that stand on their own!

No need to apologise Stuart, we love any excuse to bang on at length about out favourite subjects!

I agree with John that clear coats are better than darker, and I agree with Steve that there are better products out there, but my vote goes to Bilt Hamber Dynax-UC, which is available in brushable or aerosol form.

ACF-50 is great for corrosion protection in seams and stuff, but IME it doesn't stand up well to the kind of attrition that the underbody gets exposed to -hence the self-sealing waxes being better in my view.

Thanks- but some clarification please.
' Check that galvanising is OK' - how to determine its not ok? As on the photo, the exposed areas are white powdery metal finish and not rusty, which I thought was the galvanising corroding.
'Rust treatment' -it's not actually rusty, so suppose I can wire brush, cold galvanise paint, and then under seal or clear wax oil on surfaces and cavity wax internally.

Has someone been using that area to jack up the car?

I don't think so, there are lots of places like that all over

Steve T,
I miss read your post and I thought why is he wearing a mask and a dress? I know Healey drivers have a different life style but that's going a bit far

Very odd as the black sticky stuff (DiNitol I assume?) on my Roadster is still sticky and only comes off by contact wear such as jacking, yours looks quite dry on a second look. That's up the sides isn't it?


Have you been off roading such a parking in grassed areas?

I believe that underseal may have been optional at some stage? That photo looks like a galvanised chassis with thin brush applied black paint. as Mark pointed out, the black Dinitrol is super effective but difficult to cope with when you need to dismantle things.
I wouldn't use a wire brush on the galvanised surface. Try using a rag soaked in white spirit and see what remains. Then you have a choice of applying Dinitrol, or Tectyl 506 is also excellent.