Series 3 What is this coating?

Hi, just wondering what this black coating/covering on the chassis? Looks like it’s been there for a while. In some places it’s sticky/greasy in others, dry and cracked. It covers the chassis and is also on the bulkhead and in the engine cavity.

Does it need to be removed before I recoat it with something like waxoyl? Or can I just apply over the top? Thoughts?

Thanks as always!

Probably old waxoil type coating. Or anything else someone might have sprayed/brushed/daubed with their fingers to protect the chassis. Best to clean whole chassis up as best you can before applying complete new product. After that you can top up. Try searching chassis treatment or similar on here, there's loads of threads on it.

Edit: check area around the sticky patches for anything leaking onto chassis

Great, thanks for the advice!

Rugby and Land Rovers said:

Hi, just wondering what this black coating/covering on the chassis? Looks like it’s been there for a while. In some places it’s sticky/greasy in others, dry and cracked. It covers the chassis and is also on the bulkhead and in the engine cavity.

Does it need to be removed before I recoat it with something like waxoyl? Or can I just apply over the top? Thoughts?

Thanks as always!

Click to expand...

If it's sticky and greasy it's probably someone's home made recipe of waxoyl/diesel/old engine oil or just old engine oil and often applied over road dirt or dried mud. Scrape any bits of coating with your fingernails then make what is in your nails into a little ball with your finger tips. If you can do this it's Waxoyl, Dinitrol or Waxoyl underseal. If you can't do this the bit of coating is probably either old bitumen type underseal or schutz. Remove as much of the waxoyl/dinitrol stuff as you can with a scraper. If some stays on and sticks tenaciously then it's probably ok to apply waxoyl over the top. (It will soak into it and form a new amalgam). If you can't remove the old bitumen or schutz don't worry too much. It will eventually come off as the rust underneath it festers and as you are doing a diy job you will need to clean the chassis and apply waxoyl at least every year anyway. I have to tell you that on heavily rusted bits, even applying once a year is not going to be all that effective. You should really take a week or two or three week ends to abrade the rust off as well as you can. Use an angle grinder on really heavily rusty bits. Spread a plastic dust sheet underneath to collect all the debris. You are likely to have rot in at least two or three places. Stab suspect areas hard with a screwdriver to find them then get them welded.

Edited to add: If you are grinding or wire brushing the rust it goes without saying that you need a particulate mask of course. And goggles.

It looks to me like the chassis has been painted with bitumastic paint and then schutzed over the top. The schutz has crazed because it doesn't get on with the bitumastic. I have an area of chassis on my LR which looks like this and that is what caused it.

Cleaning the crap and rust off a chassis might be doable if the body is off or there is car lift available but lying under the bloody thing for days whilst scraping, grinding and wire brushing sounds like hell on earth to me. Even with the the best will in the world there will be the odd crevice where rust is festering that can't be got at by lying under it flat on your back. My preferred method of operation is to let the chassis rust to the point of mot failure then decide whether to get a new chassis fitted or sell it to someone who is more masachistic than me.

Col