Underbody Rust Protection

[s99sdp]

Hello wise and wonderful people.

I will soon be starting to scrape off the old crud and wire wheeling the underside of my Mk3 Spit. My car ins't a show pony and won't be winning any awards so I'm looking for suggestions of what I can spray or brush on to the underside of the tub and chassis to prevent rust. 

I've been warned that some stuff on sale can be flammable and to steer clear of it and I'm also looking for something thats going to last a few years as I don't really want to be doing this each year. 

If you have any suggestions they would be gratefully received.

SP

[ahebron]

Asking about underbody protection is like asking what oil or what tyres to use so tread carefully.
But a bit of advise I have is if you clean the underside back to bare metal with a wire wheel or suchlike then go over it all by hand with a 60 grit scourer. The wheels will remove the paint etc but then will polish the metal, the 60 grit will give a surface that will hold the particular product you are applying a lot better than the wire wheeled one.

[Paul H]

I like Bilthamber products . Other makers are available 

Paul

[NonMember]

If you go back to bare metal then I would apply a paint product first, then the underbody seal product on top of that.

I use Dinitrol products on mine but I understand Paul's preferred Bilthamber ones are equally good.

All underseal and most paint is flammable when applied. Most of them remain flammable if you get them hot enough, but very few will self-ignite under realistic conditions. If your floor pan is hot enough to worry about the underseal burning then your carpets are already on fire. Do avoid getting it on the exhaust, though. I've seen a modern car set fire to the boot floor mastic due to heat transfer from the rear silencer (admittedly on a rolling road where it was being driven hard).

[Clive]

50 minutes ago, s99sdp said:

Hello wise and wonderful people.

I will soon be starting to scrape off the old crud and wire wheeling the underside of my Mk3 Spit. My car ins't a show pony and won't be winning any awards so I'm looking for suggestions of what I can spray or brush on to the underside of the tub and chassis to prevent rust. 

I've been warned that some stuff on sale can be flammable and to steer clear of it and I'm also looking for something thats going to last a few years as I don't really want to be doing this each year. 

If you have any suggestions they would be gratefully received.

SP

I have just done my Dolomite. 

I used the thin Dinitrol stuff to cover everything, creep into seams, and in box sections etc, fantastic stuff and very very similar to Dynax s50

Once that had flashed off, I then used the dinitrol hard underbody wax for the wheel arches and exposed bits of the underside. It is fantasic stuff, looks like underseal but it is waxy. 35k on my spitfire in all weathers and it is just starting to disappear in a couple of high impact areas. Still soft enough to offer great protection though.

 

[Badwolf]

+1 for Dinitrol products although I also use Bilthamber stuff for other needs.

[ed.h]

3M Schutz is a respected product.

Ed

 

[ahebron]

I was advised and used a zinc phosphate primer, then then a protection paint followed by rattlecan red on the Vitesse 6.
This was after I stripped it back after I saw the professionally applied coating flaking off.

[s99sdp]

7 hours ago, ahebron said:

I was advised and used a zinc phosphate primer, then then a protection paint followed by rattlecan red on the Vitesse 6.
This was after I stripped it back after I saw the professionally applied coating flaking off.

Wow! It looks like I'll be under my car for quite a while.

 

 

[s99sdp]

On 22/08/2022 at 15:51, ed.h said:

3M Schutz is a respected product.

Ed

 

What was the prep for that? Anything special?

 

SP

[Jon J 1250]

This is how I'm doing it, seems to be going well so far.

I wish I could use a sandblaster but I don't have the facilities for that, plus I am getting back to bright metal well enough, It's just a LOT of work!

Cleaning back to bare metal, acid etch prime, 2-3 coats of satin black, 2 coats of wedgewood blue (the whole car will eventually be restored into this colour), leaving some black showing through the overspray as per original paint.

Then a good coat of Lanoguard spray, with Lanoguard grease painted over the seams.

As expected holding up well so far, I'll try and do an update in 5 years or so...

JJ

 

 

[steveo]

My 2001 Ford Ranger chassis was in amazing condition for a 20 year old pickup, with only surface rust & never welded, to keep it good it got the wire wheel treatment, 2 coats of red oxide type anti rust primer then 2 coats of black gloss & waxoyl on top.

I spray with it with waste oil when it gets serviced, after 18 months of living outside in all weathers its still looks good & the MOT tester loves it !

 

[ed.h]

13 hours ago, s99sdp said:

What was the prep for that? Anything special?

 

SP

I sandblasted to bare metal, shot a couple of coats of two-part epoxy primer.  Then the Schutz.

Ed

[Unkel Kunkel]

On 22/08/2022 at 09:56, NonMember said:

 

All underseal and most paint is flammable when applied. Most of them remain flammable if you get them hot enough, but very few will self-ignite under realistic conditions.

Yes.. it is flammable.

Not just in relation to the the vehicle,  but it applies to whatever you cover the floor with to catch the drips etc.

Someone, who must remain anonymous,  gathered up (the now -dry ) odd bits of hardboard etc that had been used to catch Waxoyl drips as they were “lying around”, and “needed tidying up”   - and added several pieces to the kindling sticks when making the living room fire.

Well, it certainly got the fire going well..

-I had’t heard  a household fire make a very load roaring noise before.

Outside,there were   sparks showering out of the chimney into the night sky.

We were on the point of calling the fire brigade but somehow it managed to settle.

It was of course, all my fault.

 

[Colin Lindsay]

15 hours ago, Unkel Kunkel said:

I hadn’t heard  a household fire make a very load roaring noise before.

Try lighting a wood burning stove with a large candle. THAT is positively frightening!

[PeteH]

4 hours ago, Colin Lindsay said:

Try lighting a wood burning stove with a large candle. THAT is positively frightening!

Spent “tea lights” make fair firefighters . Don’t have so many now the Bath has been replaced by a wetroom

Pete

[Badwolf]

Aren't there safer ways of heating water than sticking tea lights under a tin bath or have I got it wrong??

[PeteH]

1 hour ago, Badwolf said:

Aren't there safer ways of heating water than sticking tea lights under a tin bath or have I got it wrong??

Woman Thing, Sit in bath for hours, keep feeding it with hot water, surounded by tea light candle things, Book, glass of Wine etc;. All now redundant as the bath went, replaced by a wetroom. Far more practical?. But not quite as "popular".😁

Pete.

P.s. just noticed the typo. No firefighters, just firelighters!!😁. My wife`s cousin, got the firefighters once. Daft B******r got her foot jambed behind the tap array trying the "turn tap on with foot" routine. Her husband, told me, and he and I all but wet ourselves laughing. He got the bill for the plumbing repair.😭

Pete

[Peter Truman]

In the very early 60's my grandmother in the NE, Norton on Tees used to light the coal fire with a gas prong which was connected with rubber hose to the gas supply, don't know what she did but it singed her eyebrows and front of her hair, she didn't have much by then in her 80's I didn't harf laugh, grandad wasn't amused, I'd been sent back for a months summer schools holiday that with other mischief me and my girl cousin got up to I think he was glad when the Co car picked me up for my return to Aus! 

[ahebron]

That reminds me of secondary school science and connecting the rubber hoses for the bunsen burners  to the water taps for the sinks.

[ahebron]

On 24/08/2022 at 22:17, s99sdp said:

Wow! It looks like I'll be under my car for quite a while.

 

 

I did have the advantage of removing the body from the chassis so it made work relatively quick and easy.
Though picking the wires that fly off from the the wire wheels out of everything that wasn't covered wasn't quick nor easy.

[NonMember]

2 hours ago, ahebron said:

Though picking the wires that fly off from the the wire wheels out of everything that wasn't covered wasn't quick nor easy.

Just one of the reasons I prefer the Scotchbrite discs.

[s99sdp]

On 24/08/2022 at 16:49, Jon J 1250 said:

This is how I'm doing it, seems to be going well so far.

I wish I could use a sandblaster but I don't have the facilities for that, plus I am getting back to bright metal well enough, It's just a LOT of work!

Cleaning back to bare metal, acid etch prime, 2-3 coats of satin black, 2 coats of wedgewood blue (the whole car will eventually be restored into this colour), leaving some black showing through the overspray as per original paint.

Then a good coat of Lanoguard spray, with Lanoguard grease painted over the seams.

As expected holding up well so far, I'll try and do an update in 5 years or so...

JJ

 

 

 

 

 

Christ thats a lot of work.

[Jon J 1250]

2 hours ago, s99sdp said:

Christ thats a lot of work.

You're not wrong, it is that, luckily restoring this car is my hobby so I do not mind.
Short of taking the car off the chassis which it doesn't need, there is no other way of doing it, so I am doing it the hard way.

The whole outer extremities of the underside is covered in surface rust where the thin factory paint has failed, it hasn't eaten into the metal in any significant way anywhere and cleans up to bright shiny steel, but laying underneath and doing this is hard work nonetheless. The Lanoguard has better do its job, I'm not doing this again!

Latest progress around the side rails (the tread plates are going to be replaced)

[daverclasper]

Hi Jon. Keep up the the good work. I'm interested, as I understand the underside only has quite weathered, though definitely non terminal/serious, surface rust.

Surprised rot hasn't got into the nooks and crannies, where damp/wet mud can sit for ages, if underside isn't regular scraped/cleaned?