Cleaning the undercariage

[Tom S.]

A few weeks ago there was athread agout cleaning the undercariage. I said at the time I thought the simple green cleaner I had used might promote rust.I did a little test by putting some of it into a coffee can along with a few metal parts. The rust on the inside of the can and the small parts is unbelievable,the top was on the can so no air got to it.The front half of my car was cleaned with Gunk and the back half with simple green and both sprayed with a small pressure washer. no rust visible to speak of any where when I started. The back half srayed with simple green now shows quite a bit of rust.I geuss my point is stick with the Gunk. I know I won't use simple green again.

Tom Stanton

#41491

[Wayne K.]

Re: Cleaning the undercariage

Tom,

Thanks for the info. I've used simple green and didn't notice this but I won't use it again on metal. Do you have any idea what is in it that causes rusting ?

Wayne

[Tom S.]

Re: Cleaning the undercariage

Wayne
I don't have a clue as to what is in the simple green. It cleans quite well but the rust problem is one that we don't need.The Gunk works pretty well I just don't like the smell of it, but I geuss i'll stick with it.

Tom

[Michael H.]

Re: Cleaning the undercariage

Tom,

I've noticed the exact thing when using simple green but I think the cause of the problem is the fact that simple green seems to remove every last spec of any oil or protection that the metal has to prevent future rust. I've done a lot of experimenting with it and have found no traces of rust or corrosion caused directly by the green. Gunk would leave the surface with a film coating that green wouldn't. I'm sure far from a chemist but I really don't think there's anything caustic in green. I'll do a little more experimenting and see what happens. I'll use a few chunks of scrap metal, one freshly ground on a grinder and the other cleaned with green and toss them outside for a few nights. I'll report back if I learn anything interesting but I think they will both look the same after a few days.

Michael

[Tom S.]

Re: Cleaning the undercariage

Micheal
As I stated I PUT SOME SCRAP AND SOME SMALL PARTS IN A SEALED COFFEE CAN.Sorry about the caps.Any way the can ,the rim around the top and all the small parts ,scrap and all were badly rusted.let us know what your findings are, but I don't think i'm going to be using any simple green again anytime soon!

Tom

[Michael H.]

Re: Cleaning the undercariage

Tom,

That's really interesting. I decided to try the test myself because if that's the case, I really don't want to have problems with rust. I collected several different pieces of scrap metal and ground off everything including any plating that they may have had. I have them in a covered container with simple green so we'll see what happens in a few days.

Michael

[Tom S.]

Re: Cleaning the undercariage

Micheal
Please keep us informed as to what your findings are. Maybe I'm all wet but i've tried it on different pieces and the results were the same each time.

Tom

[Michael H.]

Re: Cleaning the undercariage

Hi Tom,

The experiment continues. It's been about 28 hours so far and I just looked at some of the samples. I started with 20 misc pieces of different metal. Old nuts, bolts, small brackets etc etc. I cleaned all 20, then attacked each with the bench grinder to be sure there was no plating or any coating.

I placed 15 items in a can of simple green and covered it. I washes 5 items with green and laid then out on a dry table. As of noon today, all 20 items were bright shinny metal with zero traces of rust or corrosion.

At noon, I washed 2 of the items with water and now, at 8:45, I already see a slight haze of rust colored coating. It's not actually rust, yet, just a discoloration and dulling that is the first step to rust. I think we need another day to learn anything positive but I'm leaning towards the fact that it's not the Green that actually causes rust but the fact that it cleans every last spec of any oil residue off and leaves the metal wide open for moisture to attack. It sure doesn't take long for that to happen here in Florida so we should have some results soon.

I've noticed over the years that even cleaning metal parts in lacquer thinner leaves a film that tends to protect the metal but Green sure doesn't.

Everything that I clean to bare metal, I coat with a product called SP-350, made by CRC. I had to buy a 5 gallon pail (@ about $100. a gallon) and I've been using it for the last 15 years. It goes on thin and when set, leaves a very, almost invisible coating of cosmoline and parafin that seems to last forever. I can grind a piece of metal, coat it with SP-350 and throw it outside for years and zero rust. Pretty amazing stuff. It was originally only distributed to the military so I don't even know if it's available to the public. Check with CRC. I know at one time it was available in spray cans.

Michael

[Michael H.]

Re: Simple Green test #2

Tom,

Day two, about 50 hours in the green and zero sign of rust or corrosion on anything. I'm going to remove half of the items and rinse in water, then allow to air dry. Bet they'll be starting to discolor by morning with rust soon after. I'll keep ya posted.

Michael

[John H.]

Re: Simple Green test #2

I cleaned up most of the 35-year accumulation of crud off the underbody and rear suspension of my all-original 32K-mile '69 Z/28 two winters ago, and used both Castrol "Super-Clean" and Simple Green, rinsing with a spray bottle of water, depending on what I encountered. As I recall, straight "Super-Clean" would remove base paint, but Simple Green didn't.

[Michael H.]

Re: Simple Green test #2

Tom/John,

Day three of my test has shown absolutely zero rust or corrosion on any of the clean metal parts I've left in the Green. I removed a few more parts from the Green 24 hours ago and put them on the shelf without rinsing in water. Zero rust and still shiny today. I rinsed a few more parts in water after the 24 hours of Green and left them in the house to air dry and there's a very slight discoloration but hardly noticable. The 4th group was washed, rinsed and left outside during the storm last night and today at noon, they show some formation of rust in the early stages, just about exactly what you would expect. I'm still convinced that Simple Green is one of the safest and most effective cleaners I've ever used and as long as a cleaned surface is protected, there will be no rust or corrosion caused or accelerated by the use of Green. I'm sure that the problem that Tom had was because the surface was so completely oil free after cleaning that moisture attacked immediately and caused the formation of rust.

Hanson

[Tom S.]

Re: Simple Green test #2

Micheal
Good job! I am still going to stay with the Gunk! I think that you are correct that the gunk leaves an oily film.But in my case I don't get to paint something rihgt away so I am better off with the oily film than the rust.Thanks again for your input.

Tom

[Michael H.]

Re: Simple Green test #2

Tom,

I agree. At least it will protect until your ready to refinish the metal.

Michael

[John Walker]

Re: Simple Green test #2

Here is somthing for you all to ponder, the U.S.F.S. has designated that "Simple Green" causes hydrogen embrittlement and will not be used on any aircraft to be contracted to them!

[Michael H.]

Re: Simple Green test #2

That's pretty interesting. Where did you read this?