Ring Flush

[Kerrville]

Based on a recent borescope inspection, we have decided that my valves and cylinders are quite healthy, but the oil control rings may be a bit gummy.  I want to try the ring flush procedure recommended by Mike Busch.  He recommends a witches brew of varsol, xylene, and w100.  I can get the later two, but I can't source any varsol.  Can anyone suggest a good substitute?  Possibly straight mineral spirits or even toluene?  Since it really seems like a witches brew, I was thinking of sprinkling in a bit of marvel mystery oil along with some eye of newt.

[N201MKTurbo]

Varsol is mineral spirits.

 

[Bolter]

4 minutes ago, N201MKTurbo said:

Varsol is mineral spirits.

 

Curious if you are in California, is the low VOC mineral spirits that is permitted now also an equivalent?  It is not exactly the same as what we called mineral spirits in the past.

[EricJ]

+1 that Varsol is essentially a brand name for a particular (supposedly purer) type of mineral spirits.  The brand is currently owned by Exxon Mobil.   Stoddard Solvent is similarly just a particular type of mineral spirits.   It's like "Kleenex" or other brands that have become product names; unless there's some reason to believe otherwise, they mean "mineral spirits".   Stoddard Solvent was branded as a dry cleaning agent.  There's nothing special about it for aviation use, other than it is less flammable than gasoline so safer as a general solvent.   

Another thing that is often used for ring flushes is Marvel Mystery Oil (MMO) which is usually available at places like Wal-Mart or auto parts stores.   People often use MMO straight without mixing it with anything.  FWIW, MMO is mostly mineral spirits but also has some other interesting stuff in it.    If you want you can cut it with your favorite motor oil, but it's probably fine to use straight.

Whatever you do, after the ring flushes are finished, don't run the engine until the oil is changed (probaby goes without saying, but is mentioned for completeness).

[Kerrville]

Thanks for the info.  I will just sub mineral spirits.  I thought that I may recall having read that varsol had naphtha in it.  I think that I will maybe modify Busch's mixture by subbing a quart of marvel mystery oil for a quart of the 100w aviation oil. I know that MMO was originally used to scavenge lead in the old cars back in the 30s.  Whatever they put in there to scavenge the lead would probably be helpful as I do have some lead deposits, but nothing horrible.

I currently have the oil drained and will run the solvent mix through and just let it go through.  I plan after that to put the new filter on and complete the oil change.  Worst case scenario, is that it does nothing.  I can't see it causing any harm provided I don't let it get into the exhaust like he cautions in the procedure.  

[rickseeman]

28 minutes ago, Kerrville said:

 I think that I will maybe modify Busch's mixture by subbing a quart of marvel mystery oil for a quart of the 100w aviation oil. I know that MMO was originally used to scavenge lead in the old cars back in the 30s.  Whatever they put in there to scavenge the lead would probably be helpful as I do have some lead deposits, but nothing horrible.

Do whatever you want. But if I was to try to do it I wouldn't think that I knew something better than Mike Busch.

[Kerrville]

Probably wise.  I've just always liked the stuff.

[EricJ]

25 minutes ago, rickseeman said:

Do whatever you want. But if I was to try to do it I wouldn't think that I knew something better than Mike Busch.

FWIW, many, many competent career professional GA A&Ps disagree with Busch routinely.   He has many good, reasoned opinions, and is an excellent advocate for aircraft owners, but he certainly isn't the last word in aircraft maintenance.   Just my dos centavos.

[PT20J]

I assume Mike uses the Xylene to dissolve varnish perhaps left behind by overheated oil. 

I know a mechanic that swears by flushing with MMO. He claims an FAA mechanic told him they added it to the fuel in DC-3s back when they were used as flight check aircraft to check navaids.

MMO is mineral spirits, TCP and a couple of dichlorobenzene isomers. Oh, and red dye and peppermint fragrance. The TCP might reduce lead deposits, but probably only if burned by adding it to the fuel. The dichlorobenzene is likely to dissolve carbon. 

 

[Shadrach]

1 hour ago, Kerrville said:

Thanks for the info.  I will just sub mineral spirits.  I thought that I may recall having read that varsol had naphtha in it.  I think that I will maybe modify Busch's mixture by subbing a quart of marvel mystery oil for a quart of the 100w aviation oil. I know that MMO was originally used to scavenge lead in the old cars back in the 30s.  Whatever they put in there to scavenge the lead would probably be helpful as I do have some lead deposits, but nothing horrible.

I currently have the oil drained and will run the solvent mix through and just let it go through.  I plan after that to put the new filter on and complete the oil change.  Worst case scenario, is that it does nothing.  I can't see it causing any harm provided I don't let it get into the exhaust like he cautions in the procedure.  

Naphtha is also another type of mineral spirits. I believe It was used for dry cleaning years ago. I have a gallon in the hangar that is probably nearly 70 years old. It is labeled dry cleaning fluid but the ingredients say Naphtha.  

[Shadrach]

12 hours ago, PT20J said:

MMO is mineral spirits, TCP and a couple of dichlorobenzene isomers. Oh, and red dye and peppermint fragrance. The TCP might reduce lead deposits, but probably only if burned by adding it to the fuel. The dichlorobenzene is likely to dissolve carbon. 

You missed a few ingredients…like pig fat and eye of newt.

[MikeOH]

I always preferred bat wings over eye of newt, but they're both hard to find these days...especially in Kalifornia

[N201MKTurbo]

8 minutes ago, MikeOH said:

I always preferred bat wings over eye of newt, but they're both hard to find these days...especially in Kalifornia

Probably easier than finding MEK.

[Andy95W]

A few years ago, I found some oil in the bottom of my #4 cylinder and engine oil was fouling that bottom spark plug.  I did a ring flush of that cylinder using straight MMO.  Worked very well for me.  I look hard at that cylinder every annual and it still looks good.

[redbaron1982]

What about running mmo a couple of hours prior to the oil change? That's supposed to free up oil rings as well. 

[bcg]

https://www.laballey.com/products/varsol-solvent

If you're actually in Kerrville, David has a 55 gallon drum of Varsol at Dugosh.

[bcg]

9 hours ago, N201MKTurbo said:

Probably easier than finding MEK.

https://www.amazon.com/DIYChemicals-Methyl-Ethyl-Ketone-Gallon/dp/B096SVGMN9

[Kerrville]

I imagine the peppermint to be true.  I remember that smell ever since I was a little kid when my Dad was messing with it.  On another airplane I once owned, the o235 engine had sat pickled for over 40 years.  The IA had me pour a 50/50 mix of toluene and marvel mystery oil into the crank case until it came out the filler tube.  We capped it and left it for a couple of weeks.  Then drained it out and ran some cheap pep boys oil through it.  Then, filled it up with w100 and it ran fine.  He said MMO and toluene was his go-to depickling solution.

[Pinecone]

Naptha is a better solvent (more aggressive) than mineral spirits.

Also a bit more flammable.  It is also used as fuel for camp stoves and Coleman type lanterns.

[Shadrach]

21 minutes ago, Pinecone said:

Naptha is a better solvent (more aggressive) than mineral spirits.

Also a bit more flammable.  It is also used as fuel for camp stoves and Coleman type lanterns.

Agreed. As an added bonus I just found that Naphtha can be bought at Walmart in the form of white gas for $15 a gallon.  A gallon of low odor MS from Lowes is $24 and is not as powerful nor volatile).  This is a good find for me as I use a fair amount when I pressure wash the inside and outside of my fuselage and empennage with mineral spirits at annual.  Hangar not withstanding, it's amazing how much crap can find its way into the tail section in just a year's time.  

[dkkim73]

28 minutes ago, Shadrach said:

 This is a good find for me as I use a fair amount when I pressure wash the inside and outside of my fuselage and empennage with mineral spirits at annual.  Hangar not withstanding, it's amazing how much crap can find its way into the tail section in just a year's time.  

That's interesting. Is it common to do that? (and, I mean this as a curious neutral question, is it safe/approved?) I would imagine you would dissolve a lot of things. Do you just re-grease and re-lube (spray lube) the moving parts afterward, and assume everything else that came off should? 

Thanks,
D

[Shadrach]

8 minutes ago, dkkim73 said:

That's interesting. Is it common to do that? (and, I mean this as a curious neutral question, is it safe/approved?) I would imagine you would dissolve a lot of things. Do you just re-grease and re-lube (spray lube) the moving parts afterward, and assume everything else that came off should? 

Thanks,
D

It’s common for me. As far as I know here is no basis for approving or disapproving other than deeming the solvent being used as safe and non corrosive (MS is ideal in this regard).
I am very specific about where the solvent is directed. I use a pneumatic solvent sprayer (see below) with an adjustable mixture. I clean soiled areas with MS and then blow the area dry. Moving parts are not hit with MS unless I want to remove old lubricant before replenishing.  I am more concerned with dirt and debris laying against the skin and bulkheads. I don’t want anything in there that con hold moisture. Probably overkill, but it makes it easy for my IA to verify the condition of the airframe when it is free of debris and dirt. Lots of folks on the field polishing shiny airplanes without knowing there are remnants of dirt, grass clippings, rodent and birds nests on the inside.

[Yetti]

I am not saying that MMO will help you make a stuck valve get to annual, but if you think about it the engine design and MMO are of the same vintage.    One mechanic said to pull the exhaust to get the valve back in, but using a grabber with 2 prongs cut off and holding the valve with the cylinder, was able to get it back in the hole just using the spark plug holes.

https://www.lowes.com/pd/CRAFTSMAN-Automotive-Retrieval-Tool-Kit/1003096242

[RoundTwo]

15 hours ago, PT20J said:

MMO is mineral spirits, TCP and a couple of dichlorobenzene isomers. Oh, and red dye and peppermint fragrance.

 

I hate being “that guy”, but you’ve got one glaring error that needs to be addressed so no one gets hurt.

It’s wintergreen, not peppermint. 

[PT20J]

1 hour ago, RoundTwo said:

I hate being “that guy”, but you’ve got one glaring error that needs to be addressed so no one gets hurt.

It’s wintergreen, not peppermint. 

I stand corrected