So I recently bought a mk2 Octavia VRs so that I can spend some time on getting the car exactly how I want it and I’m getting there mechanically.

My next thought is the underside of the car as it is now 15 years old and I really want to keep this car long term I want to start looking at protecting it.

I jacked her up and had a quick look today and the pinch points are pretty swollen in places also noticed the arms look pretty rusty but that’s as far as I got without removing trays etc.

My question is what would be the major things to looks to strip back and seal or replace. Also are the pinch points repairable? I will try and get some pics on here tomorrow any help is much appreciated.

I use zinc spray lavishly on anything underside and around engine bay, including exhaust (note pure, high temp 400deg C resistant zinc for exhaust, cheaper zinc-alu will do for other parts). Easy to apply and easy to top up in places every couple years or so (cars not garaged). Zinc is better than other coatings in that it offers galvanic protection also of nearby exposed areas. Pinch welds / jacking points are definitely worth zincing up then painting over as visible, but for lifting using garage lift it is best to put in lift pads IMHO, I have had them on all cars. Not expensive, easy to install, double the amount of support points and save wear on pinch welds. I usually lift using a trolley jack with a wide rubber pad on a lifting point/ pinch weld, then put a jack stand under the lift pad. Of course, much easier with a garage lift. HTH.

1 hour ago, dieselV6 said:

I use zinc spray lavishly on anything underside and around engine bay, including exhaust (note pure, high temp 400deg C resistant zinc for exhaust, cheaper zinc-alu will do for other parts). Easy to apply and easy to top up in places every couple years or so (cars not garaged). Zinc is better than other coatings in that it offers galvanic protection also of nearby exposed areas. Pinch welds / jacking points are definitely worth zincing up then painting over as visible, but for lifting using garage lift it is best to put in lift pads IMHO, I have had them on all cars. Not expensive, easy to install, double the amount of support points and save wear on pinch welds. I usually lift using a trolley jack with a wide rubber pad on a lifting point/ pinch weld, then put a jack stand under the lift pad. Of course, much easier with a garage lift. HTH.

Interesting I never thought about zinc I’ll take a look at it. It’s going to be a driveway job also unfortunately as I don’t have any access to a lift so can see it being very challenging job with a lot of grinding to before I can even think about coating it.

On an old car that has not been garaged, you will find that the original coating falls off from most suspension parts without much brushing, you just lift it and it falls off, at least here in Herts that's the case. Winter salt plus constant humidity strip away coatings. On exhaust, I usually use a tough cloth (a cut off leg of old jeans trousers) to take off rust growths, then zinc the whole thing up. If more rust grows in some places, it'l get taken off and recoated next time. It is also a driveway job for me. Does not look as pretty as uniform paint, but does the job. My Roomster still has original exhaust after 14 years outside...

This sounds a million times better that laying underneath the car all day with a grinder.

What is the zinc product you use please and where can I buy it.

Also is that all you coat it with just zinc nothing after?

I’m not really fussed if it looks pretty under there as long as it’s preserved and I don’t have to worry about it.

My cills seem solid but those pinch points are my worry as moisture gets in between the layers and eats away but I guess if I can get the flakes off and zinc coat it I’m hoping it wi be ok.

Most recent one I have used is SIMONIZ Zinc Primer Spray Paint, Weld-Through Metal Primer, but I got it at <£8 per 500ml can, not £11-£13 it seems to be sold for.

Having said that, if you wait long enough, you can get several cans of zinc-alu spray from Lidl when they run it as weekly special. By far lowest cost option and good enough for everything except exhaust.

For the exhaust, I have one from Wurth that is rated to 400deg C, but you need trade account with Wurth to buy it. Any pure zinc primer that explicitly says it withstands 400degC is good for exhaust, there are some on ebay, there used to be excellent Normfest Galva 97 at ECP, but nowadays stupidly expensive, so best do a search on Internet, just make sure it is rated to 400degC.

You could coat cold parts with cellulose lacquer after zincing them up, that extends longevity of zinc coating quite a bit. I have a towbar box mounting plate protected in this manner. However, when the coating is damaged, you would need to sand it down and reaplly zinc / lacquer. For me, it is far simpler to just keep the bare zinc and reapply where needed every couple years. For longest lasting protection, you can put 1 layer of pure zinc and then zinc-alu on top. Zinc-alu is more resistant to wear but does not stop salt spray corrossion anywhere near as well as pure zinc.

I’ve seen that in Lidl before I’ll try and pick some up asap only problem I have is I need to be doing it very soon ideally before the winter bites. I had a quick look just now my exhaust is in exceptional condition barely any rust maybe it was replaced somewhere along the line so I will only have to coat this and not much removal work on heavy rust. The sub frame and arms however do look pretty rusty so I will take them back and zinc prime. Just a question are the zinc products coloured or clear what does the finish look like.

I have an old mk2 thats now off the road due to rust. Places to pay attention to are

Front lower wings/wheel arches especially nearest door pillar. The plastic liner traps all manner of crud and rusts from inside out.

Front of rear wheel arch nearest sill and rear wheel arch where it meets bumper.

Rear tailgate around number plate.

Sills in general. The plastic stone guard becomes loose and lets moisture in.

Bottom of doors where they meet sills

Under car as you have noticed jacking points, inner sills and floor panel nearest rear/boot. Most of the front under car is covered so not too bad. Check brake lines etc.

Rear subframe on mine is very bad as well as rear and front swing arms but they are not that expensive to replace with aftermarket ones if yours are as bad as mine.

I am in a high salt area so corrosion is a major problem. I tend to buy cheap higher mileage cars and run them till they die. Mechanicly they are sound but alas the dreaded rust kills them.

Alasdair

Excellent advice I’ll be sure to check all of these areas the only bubbling I seem to have on arches is front drivers side but theres no doubt all 4 will be full of all sorts once I get in there and take those covers off I’m dreading it to be honest I just hope nothing needs cutting out and welding.

The arms do look pretty rusty too so I will replace them If need be.

In regards to the the factory plastic stone guard what do people do with it can it be removed? Would it then involve a full spray job.

Worth taking front plastic wheel arch liners off and giving a good clean. Theres a sponge like strip that supposedly seals to the botom of sill area etc but I took a bucket of fine salty mud out of both on mine. Gave it a good powerwash and then loads of waxoil afterwards. Mine was pretty bad when I finally took it off the road due to weak subframes etc. There was only on small hole in sill which I managed to fill and managed to get another MOT out of it. The stone chip protection is difficult to tell if its loose/cracked or not. On my sills there were a few obvious bubbles and when I rubbed down the paint etc found that moisture had been trapped behind. I just kept rubbing down till it was solid again. I treated the rusty bits with Bilt Hamber hydrate 80 which seemed to hold the rust back.

Alasdair

6 hours ago, Redarmy32 said:

I’ve seen that in Lidl before I’ll try and pick some up asap only problem I have is I need to be doing it very soon ideally before the winter bites. I had a quick look just now my exhaust is in exceptional condition barely any rust maybe it was replaced somewhere along the line so I will only have to coat this and not much removal work on heavy rust. The sub frame and arms however do look pretty rusty so I will take them back and zinc prime. Just a question are the zinc products coloured or clear what does the finish look like.

Zinc primer is of dark grey colour (at least high purity zinc one), zinc-aluminium primer is light grey to silver. So choice of colours is rather limited unles you coat the zinc layer with paint. Personally, I'm happy with the underside of the car being 50 shades of grey ;)