31 replies to this topic

[minimininut]

I was speaking with someone the other day who was recommending using old engine oil to spray underneath cars as rust protection. They were saying that it can get into all the cracks and crevices and dispel moisture better than waxoyl.

However, having an ask around and a read on the internet there seem to be mixed opinions on this - some say it can rot rubber (so not good for rubber mounts etc).

What do you all think - worth spraying the underside with oil or not??

Thanks!

[Rhys]

Well, it has 0 adhesive properties, smells terrible, never dries and is all in all a terrible idea.

Yes if you were storing the car it would work but as a daily drive it's not a nice or sensible idea. It will just leave oil all over the road whenever it rains and I have no idea how long it will last.

[Ferretboy221]

we use this on land rovers at work (land rover indie) and the system does work, trouble is the rustier the vehicle the better it works as the oil soaks in to the rust and forms a shell layer. anything with a lot of paint or underseal still on it is pointless as has been stated above it will just drip off.

[jaydee]

I wouldnt use old engine oil as it just makes a mess, wont last for more than a few days and leave oily roads behind you...not a great idea..
In all honesty i wouldnt reccomend this, but i do something similar on the rally car: i use WD40 on some parts, like the subframes, and use grease on some parts of the underneath. That still makes a mass and you have to clean and regrease parts on reguar basis, but it works.

[firstforward]

I can recommend waxyol 85% mixed with ACF50 15%, it goes on thin watery so best use a compressor with the correct gear, it really penetrates deep. With the correct applicator its really goes far so you can apply just a thin layer and get into box sections easily. Just make sure its done in a ventilated room and use a good mask because it really produces a fine mist.

http://www.learchem....cts/acf-50.html

http://www.rust.co.u...5093&p_n=405093

http://www.machinema...twin-respirator

[donjarr]

The key to using waxoil is to get the pump up sprayer kit which comes with sprayer head and long plastic pipe for cavities and put the can of waxoil in a bucket of boiling water and it turns super runny, like water.

As for the ACF50 stuff I am kind of hesitant about the benefits of putting a protective substance specifically designed by the aerospace industry to protect aluminium in with waxoil. Not saying it's a bad idea, just unsure apart from to thin it down why you would put this in. If it's just to thin, as I said put waxoil in a bucket of boiling water and it goes like water.

Anyway on waxoil give the areas you're going to spray a good wire brush first to remove any crud and muck, and give it a thin coat. Another mistake is people think a thick layer is better, but in fact a thick layer will dry out over time and shrink and crack leaving gaps for moisture and water to get in.

[Tamworthbay]

Dynax S50 from bilthamber.com is the stuff to use. It is light years ahead of waxoyl. I use ot on my daily driver MGB GT and there has been no noticeable change over four winters.

[JustSteve]

For areas like sills and other box-sections, mix old engine oil with waxoyl.

A bit pointless putting it on the underside of the car really, and there are many products that are designed for the job that will work better too

[pdaykin]

Old engine oil under an everyday car is a pretty poor way of protecting it.

I wouldnt bother using old engine oil. It smells and when mixed with waxoil makes the wax too thin. It then runs out making a horrible mess everywhere.

If you are going to use waxoil (or similar) use it the way it was meant too - heat it up rather than thin it down.

Dinitrol is also pretty good.

[minimininut]

Fab, thanks for your replies, lots of tips and ideas there too - sounds like waxoyl and other products are a much better idea than engine oil, so I think me and Arthur will be stick with products actually made for the job of rust protection!

[Andyagl]

The best thing old engine oil is used for is mixing with cerosote and painting fence panels. Other than that, i wouldnt use it for anything.

[tiger99]

Don't use old engine oil for anything. Get rid of it at the council recycling site. It is seriously carcinogenic and contains toxic heavy metals. Remember that you or your mechanic has to work on your car, and at some time it will need body repairs, when that oil will be a serious health hazard. It is not all that good at rust prevention anyway, and in certain cases its acid content may even accelerate corrosion. As for painting fences, well you may be exposing your or youir neighbours kids to carcinogens.

Oh, and always wear appropriate gloves (nitrile is best) when draining the old oil. New oil is relatively harmless.

Edited by tiger99, 11 August 2012 - 11:50 AM.

[Tamworthbay]

Anyone remember the world record holding Beetle on blue peter in the lates seventies or early eighties? It have covered a ridiculous number of miles and the owner (German I think?) explained how he painted the whole car in its own used oil, top as well as bottom. Anything that helps keep Beetles on the road is to be avoided at all costs.

[tiger99]

I think that the hazards associated with used oil had not been fully appreciated at that time! Still, I do agree about Beetles, and their derivative, the horrid Porsche 911.

On the other hand, someone who lives very near me has a lovely MK 1 Golf convertible. in very nice condition. VW did eventually learn how to build proper cars, but they only learned by copying the Mini, as did everyone else.

[Rog46]

Old engine oil under an everyday car is a pretty poor way of protecting it.

I wouldnt bother using old engine oil. It smells and when mixed with waxoil makes the wax too thin. It then runs out making a horrible mess everywhere.

If you are going to use waxoil (or similar) use it the way it was meant too - heat it up rather than thin it down.

Dinitrol is also pretty good.

Dinitrol came out TOP in a recent Practical Classics report!