Herald 12/50 - Cleaning up and rustproofing underneath

[Jon J 1250]

Hi,

My '65 12/50 is very strong underneath, has never been welded but was covered in oil to preserve it years ago and now as the oil has dried out is covered in spots and patches of surface rust. See photos

What is the best way to preserve and protect this from further deterioration, all I can think of is a wire brush, paint with a good rust converter and apply a good coat of wax like the brown Bilthamber product?

Is this the best I can do, short of basting and painting it properly, thing is the car is too good to spilt from the chassis for shot basting, can you put the car on spit and rotate it to blast it with the body on chassis?...still seems like overkill....but its not possible to get the wire brush everywhere, like in the side rail.

If anybody has any thought or experience at dealing with this, any advice would be gratefully received.

Many Thanks 
Jon

[PeteH]

Looking at it, I would be tempted to get as much loose stuff off and then resort to something like the "bilthammer" products? (others available). And get something injected into the chassis and A/B Posts etc;

Pete.

[chrishawley]

That's a hard one. Most areas have survived extremely well but rust has got a stronger grip in some of the outer sections. I wouldn't fancy 'spinning' a whole, intact car complete with mechanicals. Health and safety waiting to happen. And, without complete dismantlement, media blasting would have much the same effect as doing it by hand i.e easy areas would clean up lovely  - but the nooks and crannies would be the same problem.

Can't tell everything from photos but my own inclination is to consider the areas as two domains:

1) Those which are accessible to wire brush (and suchlike)  and can be brought up to clean(ish) metal. In which case I'd go Bondaprimer> Dulux Exterior gloss> any wax.

2) Inaccessible areas (e.g undersides of outer riggers). Physically remove as much scale  as possible and where possible and then WD40> Supertrol> >a really heavy wax

WD40 will chase into every seam but also flash off quickly. Supertrol is very thin and will creep into seams and into scaly rust - but does not have much 'body'. And for a heavy wax old skool Waxoyl can provide a thick coating as an atmospheric barrier. Or. one step beyond, Hammerite under seal with added waxoyl.  Stays tacky for a couple of years.

Rust inhibitors (e.g. Jenolite) may not be a great help in you particular situation. For sure they have their place but on advanced scaly rust just tend to put a iron phosphate layer on top of deeper iron oxides.

 

[Clive]

I think putting it up on a ramp would be worthwhile if the  car is that good, get it cleaned as much as possible and remove as much rust using mechanical methods. Then possibly a quality rust converter. Messy and time consuming, but without blasting it is all you can do. Probably worth removing the sills though.

Not sure I would be using paint, but rather a good coating of a super thin "wax" like s50 or dinitrol 3125. And then once that hs soaked into the surface and seams apply some dinitrol hard wax finish. I have used that on the exposed areas of my spitfire with excellent results. It is like an underseal, but has a consistency similar to a hard shoe polish, if that makes sense. It is in place since I finished building  the car in early 2015 (wow!) and has had plenty of use in all weathers. The hard wax is all still in place, I was expecting to top it up annually.

[daverclasper]

On surface chassis rust, I have sprayed diesel, then Waxoyl (mixed with some engine oil, which does seem to stop it drying out). I think there are better products, than modern Waxoyl now.

In the none exposed to spray areas, it has stayed oily/greasy for 8 years (though I redo the exposed areas every 2/3 years),  and clean mud/debris, from the places that trap it it, every year, and when I'm under car. Underneath appears to have not noticeably deteriated in that time, It's used in all weather, all year around, though try to avoid salt, and not a daily driver as such 

[Jon J 1250]

Thanks everyone, these cars were not really painted all that well underneath from new so I guess it must be doing ok for 60years old.

I am going to start off with drill mounted stiff nylon brushes to get the dirt and old oil off all the surfaces and crevices, without taking what remains of the paint off, then will focus on the surface rusty areas with a rotary wire brush, then think there probably isn't any point in painting, may do a coat of good quality rust convertor for what its worth, then will go over it in a dark wax, not too thickly, and will have to keep inspecting it each year.

The car isn't likely to get too much wet use, but need to get the balance right, I don't want to be scared to use it.

It going to be a lovely job to do, but sounds like there aren't any shortcuts.

JJ

[NonMember]

32 minutes ago, Jon J 1250 said:

then will focus on the surface rusty areas with a rotary wire brush

I would recommend a Scotchbrite disk in preference to wire brush. I find them more effective and less prone to disintegrating and embedding bits of themselves in anything within range.

[Clive]

4 minutes ago, NonMember said:

I would recommend a Scotchbrite disk in preference to wire brush. I find them more effective and less prone to disintegrating and embedding bits of themselves in anything within range.

By that he means in you! The only prtection seems to be a leather jacket, the wires penetrate almost anything. To be fair, angle grinder versions are much worse than drill mounted type.

[Jon J 1250]

and so the hard work begins.

After a couple of days of it, don’t think I can stand working under the car in a full face mask trying to brush and grind this all down to bright metal…let’s see how it goes I’ll do my best with it, scraping and scotch wheeling the loose off, then using the best surface treatments, coatings and waxes money can buy!  (taking on board the generous advice given above) 😁👍

 

 

[Bfg]

Late to your party, but I think from the photos I'd lift the body, borrow, buy or make a wheeled rotary spit, and then use low pressure a shot blasting gun. I've seen this done by a chap in the States and he did just one section at a time before painting it ..so it wasn't such a dramatic task despite work periods fitting inbetween rainy weather.  He'd do a few hours, sweep up the yard of grit, give the cleaned / blasted area a coat of paint ..and that would give it enough time to dry in the evening and overnight before he tackled the next section the following day.   

To me that's the only way to do the job properly and in the end I think might be quicker than struggling to do things with rotary brush and scotch wheel tools from underneath.  After all, most likely a lot of the rubber under the car would need replacing by now too, likewise brake & fuel pipes and wiring, cables, exhaust mounts & their clamps, etc.  ..and everything on the chassis is easier (read quicker and better done) when access is not via crawling under the car.   With a car that's not been molested by budget welding - I think the old girl deserves a make over once every sixty years.

I have in the past, with my Citroen, tried using chemical rust converters to get rid of the rust. That appeared to work great at the time but thereafter I still had rust stains coming through the new white (2-pack) paint, from in the overlapped of the panels. It was as if rust converter carried on even after I had jet washed it away and dried the car in breezy summer air (you remember that sort of air ??).  I'm reluctant to use any sort of chemical converter again.   

Hope that helps,

Pete

[ahebron]

When I had to repaint the underside of my Vitesse 6 due to incorrect prep by the painter (pint flaking off)I stripped it back to bare metal with a knotted wire wheel on an angle grinder, make sure you are covered head to toe with PPE and the wee bits of wire flying off the wheel can and will go anywhere.
What I was told to do after getting it to bare metal before painting was to scour the metal with an 40/60/80 (your choice) grit scourer pad.
The theory behind this being that the wire wheel ends up polishing the metal smooth and the scourer will give it a bit of texture for the paint to adhere to.
I then put a nice coat of zinc phosphate primer followed by an underseal type paint then an approximate body colour topcoat.

I did have the advantage of being able to remove the rear tub from the chassis and invert it on scaf planks and saw horses.