Best method to remove old gearbox grease that has turned to sticky goo??

[learmoia]

A friend of mine brought me a Rivarossi Big-Boy that didn't run, and it turns out the only problem with it is the gearbox was caked in grease that aged into sticky goo..

I pulled the gears (some plastic, some brass) and wiped the excess off (and out of the gearbox but they are still sticky.. )

I'm not sure what I can clean them in to safely dissolve the stuff.  At first I thought warm dawn dish soap, but that's not cutting it.

I've got some Castrol super clean de greaser (purple bottle) that is great for stripping paints that should be safe on plastic..

But these parts are expensive to replace if they got dissolved or broken..

Thoughts?

~Ian

[djconway]

Your best bet may be to get in there with a tooth pick, and scrape out 90% of the crud.  Then a soft tooth brush should handle the rest.

[oakcreekco]

I've been using CRC QD Contact Cleaner. Plastic safe.

Disassemble trucks, spray on, then use a toothbrush to remove crud.

Fast and easy

[spookshow]

I think it was @mmagliaro who told me that the only real way to get rid of old Rivarossi "peanut butter" is to take everything apart and cleanse all the gears with alcohol.

-Mark

[peteski]

Alcohol (91% or stronger) works ok, but I guess since it is a polar solvent it does not work on grease as well as naphtha.  Naphtha is what I use for removing all sorts of really nasty grease from my models.  Works great.  Bestine (heptane, similar to naphtha) would also work well.  I clean the gunked up items in an ultrasonic cleaner.

While modern slippery plastic (Delrin or similar POM) gear-train parts is completely unaffected by naphtha, I would not leave any older mechanisms (like Con-Cor or Rivarossi) in naphtha for any prolonged periods.  But in the time to takes to  remove the hardened grease, the plastic will be safe.

EDIT:  Do not use Super Clean on any metal parts! It has Lye in it and that will attack many metals.

BTW, naphtha is available as Ronsonol Ligher Fluid, VM&P Naphtha in hardware stores, and I believe i tis also sold at Coleman Camp stove fuel.  I but the stuff from the hardware store in quart size cans.  It is always good to have ample supply of this excellent degreaser. 

[brokemoto]

They are expensive to replace IF  you can find them.  As I understand it, half of the dies are lost, worn out or broken. 

I have had the best luck with alcohol, a tooth brush and elbow grease ("knuckle grease" in some cases).

[mmagliaro]

It was me who said that, and yes, I've had to do this.  Forget trying to "get in there" with brushes or a toothpick.  That white sticky goo gets everywhere, and even if you do use tools and a solvent to clean out as much as you can from the outside, what has partially dissolved will migrate around in there and then reharden.  You really have to strip the whole thing down: all gears out, drivers out, screws, washers, everything.  It has to be completely cleaned and all that stuff washed out of the frame.  While Peteski's suggestion of other solvents probably works, I found that alcohol did the trick and did not harm any of the parts.   I poured alcohol in a shallow little dish and let parts soak in it, then brushed them clean with a soft toothbrush.  Then start over with clean alcohol and do it again.  Maybe 3 times will be necessary.  You really want all that junk and the RESIDUE from that junk to be gone.

Fortunately, those old Rivarossi mechanisms are pretty chunky in comparison to a modern steam loco model, so they are not too difficult to take apart if you are used to tinkering with steam mechanisms at all.

[peteski]

I have been using Naphta for decades and never had it cause any damage. I just put in a disclaimer because I know that the spokes in Rivarossi drivers are made from what seem like some sort of softer styrene-like plastic.  Having said that I have cleaned many Rivarossi drivers without any problems.  Naphtha in my experience works so much better than alcohol, especially in the hardened grease.  Just another solvent in my arsenal of chemicals.

And just saying "alcohol" seems also misleading to me. Someone might just grab some70% rubbing alcohol, and they will be futzing for a long time to get the grease out.  The alcohol should be at least 91% Isopropyl alcohol. When I need alcohol for some tasks I use 99% IPA, again from a hardware store.  I suppose Denatured  Alcohol woudl also be usable (it is full strength).

[robert3985]

As Peter has mentioned, Heptane (Bestine) will work also.  It's become a little more difficult to find, and it can't be shipped by air.  Look for "rubber cement thinner" if you do a search.  Also Dick Blick art supplies is a good place to start looking.

I have used Bestine for years since I discovered it out of High School when I went to work with Battelle Laboratories as a graphics & technical artist.  We removed wax with it after waxing callouts on technical artwork and it was readily available at the local art stores then.  Since graphic artists don't do actual physical lay-up work any longer, its use has diminished.

Also, I've found that heating up your parts with a hair dryer will cause old grease to soften up, so you might want to give that a try.  Just don't heat your plastic parts up too much for fear of warping or melting.  Hand-holding the part while warming it usually prevents overheating.

Cheerio!
Bob Gilmore

[Simon D.]

Definitely endorse naphtha as a cleaner and it's readily avialable.  I would also recommend an air duster - compressed air in a can - to flush out the dregs, although a thorough strip down and full clean is good practice.  Another cleaner recommended to me is the other lighter fluid/camping gas, butane, which will also flush out nasty gooey stuff.

[peteski]

Definitely endorse naphtha as a cleaner and it's readily avialable.  I would also recommend an air duster - compressed air in a can - to flush out the dregs, although a thorough strip down and full clean is good practice.  Another cleaner recommended to me is the other lighter fluid/camping gas, butane, which will also flush out nasty gooey stuff.

Lighter fluid and camp fuel are naphtha. Same stuff.  VM&P Naphtha from hardware store is usually the cheapest. Lighter fluid (usually Ronsonol brand) is used in old fashion Zippo lighters. Butane is totally different.  That is a liquefied compressed flammable gas to be used with butane-typ lighters.

[Simon D.]

Peteski.  I obviously didn't express myself properly.  I know naphtha and butane are fundamentally different, but both are used in lighters.


Butane is also a solvent - used in the industrial extraction of cannabis oil according to Wikipedia.  I was given the tip to use it by a very old N Gauge hand in the UK, and have have used it a couple of times.  It does work.

[learmoia]

Thanks for the input.

I did a 91% alcohol soak last night (since I had it on hand for stripping paint)  Seemed effective in loosening and cleaning the gunk when combined with a soft toothbrush.  I'm going to reassemble one gear set and test.  If it is still stiff (from residue), I'll get some naphtha and try that on a short soak.

[mmagliaro]

Once you've soaked and brushed, I think you will find improvement if you do it a second time.  It's an iterative process (like washing your hands with soap, rinsing that all off, and then doing it again).  It's hard to actually flush out all the goo and residue in a single pass, not matter what solvent you are using.  It's not so much that any particular solvent can't get it all off.  It's that the solvent itself is so contaminated with the goo it has removed that it's impossible to get rid of it all in one go.  It's like trying to strip paint off a board in one shot.

[peteski]

Peteski.  I obviously didn't express myself properly.  I know naphtha and butane are fundamentally different, but both are used in lighters.


Butane is also a solvent - used in the industrial extraction of cannabis oil according to Wikipedia.  I was given the tip to use it by a very old N Gauge hand in the UK, and have have used it a couple of times.  It does work.

Simon, under normal atmospheric pressure butane is a gas.  It is sold in small aerosol-like pressurized containers. How are you using gas for cleaning things?   Even if you manage to release the liquid from its storage container, it instantly turns to gas while also cooling down.