Maynard Mystery Oil

[rmaynard 15,489]

I have a 60 gallon air compressor in my shop. In the spring of 2021 I noticed that the air hose was covered with sticky oil. So I cleaned it off with mineral spirits, and it was good for the whole summer and fall. Now, today I go to the garage to air up some tires, and notice that the entire length of the hose is again covered with oil. I have no idea where it is coming from. My air shut-off valve has been closed. I always close it every time I finish using it. The oil level in the compressor has never dropped. Water was drained before winter. Thus the Maynard Mystery Oil.

 

Anyone else have this problem or know what is causing it?

 

 

[stevasaurus 22,756]

That has Peter Lena voodoo all over it.  Are you sure you guys aren't related??  

   Quite honestly Bob, never seen anything like that.    

[ranger 1,750]

I’ve come across a similar? sort of thing on items like auto steering wheels, soft touch power tool handles etc, stored in cooler environments, especially if the air has a higher moisture content! I’m not sure if it’s the material degrading, or some form of mould? The cases I’ve encountered usually are quite sticky to the touch.

[Snoopy11 5,714]

Maybe some kind of oil in the actual hose material itself that is coming out with certain temperatures.

 

Don

Edited February 9, 2022 by Snoopy11

[rmaynard 15,489]

I have a length of blue air hose down in the pole building. I'm going to bring it up and see if it does the same thing.

[Snoopy11 5,714]

1 minute ago, rmaynard said:

I have a length of blue air hose down in the pole building. I'm going to bring it up and see if it does the same thing.

 

Things dry out in the cold... maybe... that is what is happening? The hose is shrinking in the cold, and forcing the oil out of the hose material...

 

Don

[squonk 41,131]

A lot of high quality air hoses have an oily feel to them. I think it's a chemical to keep the hoses from dry rotting and offer UV protection.

[ranger 1,750]

If it’s oil, that will always be present in the air from the compressor, (unless it’s an oil free pump), there shouldn’t be a significant amount if rings etc are ok. And if it's permeating through the hose walls, or if it’s oil or whatever used in the manufacturing process of the hose, I would consider the structural integrity of the hose to be compromised, and would seriously think about replacement. Burst airlines are capable of inflicting serious injuries to eyes etc!

[rmaynard 15,489]

25 minutes ago, squonk said:

A lot of high quality air hoses have an oily feel to them. I think it's a chemical to keep the hoses from dry rotting and offer UV protection.

You wouldn't want to get the oil on your clothes. It's very hard to get out. I think the problem comes down to the fact that most houses that you find today at Walmart, Amazon, Lowes, TSC, and Harbor Freight are all made in China. I do not remember where I bought it, but it was probably from HF.

I had mentioned the blue hose that is in the pole shed. Just checked and it is oil-free.

[squonk 41,131]

1 minute ago, rmaynard said:

You wouldn't want to get the oil on your clothes. It's very hard to get out. I think the problem comes down to the fact that most houses that you find today at Walmart, Amazon, Lowes, TSC, and Harbor Freight are all made in China. I do not remember where I bought it, but it was probably from HF.

I had mentioned the blue hose that is in the pole shed. Just checked and it is oil-free.

I have some of the black hose (Merlin?) brand hose from HF and had a slippery coating on it. It's probably the oil leeching out.

[rmaynard 15,489]

24 minutes ago, ranger said:

If it’s oil, that will always be present in the air from the compressor...

It's a three year old compressor. No blow-by. There is no oil getting in the hose from the compressor. I have a water/oil separator ahead of the hose. When using it continuously like when I'm bead blasting, I get water, but never any oil. I'm assuming that the oil is from the manufacturing process of the hose.

[ranger 1,750]

There will always be minute amounts of oil in the air from an oil lubricated compressor, this is the reason you should always use a ‘Coalescing’ filter if using an air fed mask for paint spraying etc, to avoid the risk of pneumonia etc. although the amounts you are experiencing suggest that the issue is elsewhere.

[Achto 27,591]

I'm of no value on the oily hose issue, sorry.

 

On the note of hoses, I have switched to using the Flexzilla air hoses. They are awesome!! they are just as flexible at -10 degrees as they are at 90 degrees. Pricey, but worth it in my opinion.

 

https://www.amazon.com/Flexzilla-ColorConnex-Industrial-Lightweight-ZillaGreen/dp/B01BGMQVIU/ref=asc_df_B01BGMQVIU/?tag=hyprod-20&linkCode=df0&hvadid=309869401414&hvpos=&hvnetw=g&hvrand=1902998510724929487&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019452&hvtargid=pla-493502059383&psc=1&tag=&ref=&adgrpid=63364097444&hvpone=&hvptwo=&hvadid=309869401414&hvpos=&hvnetw=g&hvrand=1902998510724929487&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019452&hvtargid=pla-493502059383

 

Also available at many brick & mortar stores.

Edited February 9, 2022 by Achto

[squonk 41,131]

I got one of those flexzilla  coil hoses. It is freaking awesome and pricy. No way Cousin Jim would cut loose with the cash for one for his fancy shamsy compressor! Or would he?

Edited February 9, 2022 by squonk

[wh500special 2,184]

Guessing here…

 

It’s most likely plasticizer used to process the plastic or rubber hose sheath and to make it soft and pliable.  
 

Rubbers and plastics have varying degrees of hardness which is especially dependent on the degree of crosslinking present.  Plasticizers are big, heavy molecules that “get in the way” of the crosslinking process and make the material more pliable and tougher.  

 

PVC is a great example of what plasticizers can do to plastics that are fundamentally the same thing.  PVC pipes are hard.   Not much if any plasticizer in them.  PVC beach balls and shower curtains are soft and flexible.  Lots of plasticizer in them.  
 

In your hose it could be off-spec manufacturing.  Might just be the conditions in your garage that contribute to it coming out and staying put on the surface.  
 

Eventually plasticizers come out of the stuff they are blended into.  This is why things get more brittle over time and deteriorate. Most of the time they evaporate into the air.  In this case they are coming out faster than they evaporate.  Maybe due to cool temperatures. 
 

That filmy/foggy crap that accumulates on the inside of your car windows has a lot of plasticizers in it that evaporated out of your seats and interior components.  When enough of it leaves your dashboard starts cracking and your headliner starts falling down. 
 

This is one more of those things we will look back on in the future and concede that we were knowingly poisoning ourselves.  
 

I can’t guarantee this, but I’d bet the hose is still safe to use.  The braided fabric inside it is doing the real work of holding it together under pressure.   The outer coating is just there for sealing leaks and providing abrasion resistance.  
 

Steve 

 

(if there are any real chemists here @dcrage I know I left myself open when talking about cross linking and thermoplastics in the same breath, but the point I was making was about the steric hindrance which applies to both cases.)

Edited February 10, 2022 by wh500special

[wh500special 2,184]

As soon as I posted this it occurred to me it might also be a release agent used in the extrusion process to keep it from sticking in the die as it’s pulled through.  Less likely, but possible. 
 

formulators would watch that pretty closely as it would likely affect bonding to the layers underneath if used in excessive amounts.   
 

Steve

[lynnmor 7,307]

I had some hoses get a sticky substance on the surface.  Cleaning with a solvent would help for a while, but the trash can was the best answer,  I think it is some kind of Chinese virus multiplying on the surface. 

[kpinnc 12,065]

17 minutes ago, wh500special said:

This is one more of those things we will look back on in the future and concede that we were knowingly poisoning ourselves.  
 

 

Speaking of which- is it just me or does the hose not look like a 50 foot hotdog? 

 

Maybe I just need to go make a sandwich. Sheesh!

[formariz 11,987]

Your problem is actually rather common with that type of “rubbery” hose. It actually happens a lot with Good Year brand hoses. I don’t know the exact cause but I suspect that it is sort of a reaction hose material may have with something in the atmosphere in that area. All hoses I know of that had that problem were already  at least 6 to 8 years old and once it started it always happened again after cleaning them . I suggest cleaning hose and move it out of that area to see what happens in time. 

[Jeff-C175 7,202]

2 hours ago, wh500special said:

most likely plasticizer

 

 

While reading through the thread to see if anyone mentioned it I see that you did!  Now I don't have to!

 

Google the term "plasticizer migration"

 

And don't ever leave an 8 track tape on the vinyl seats of a 74 Pontiac, or expect cheap SJ cordage to last more than 5 years.

 

 

Edited February 10, 2022 by Jeff-C175

[formariz 11,987]

@Maynard here is one of my hoses I just noticed. Oily and sticky for the first time ever. Not a cheap hose either US made and less than a year old.

[rmaynard 15,489]

It's in the air. Must be what they are spraying out of the engines of those big jet airplanes.