SPEC Grease!!!!!! OMG Help!

[rhwestfall]

Picked up a SP MK-10 (wanted the DIN that it had, and a G250 to boot). When I hooked it up, I could tell things were not right (despite a seller's claim he tested it and it was fine - long story, enough said). It's extruding silicone out under the SPEC band.

I'm tearing it down for a rebuild, but wondering what you guys use to best get all the god awful silicone out of these things before its off to the ultrasonic? Any "secrets" of a simple & effective method, or just tons of q-tips and paper towels?

 

[Pao]

Wipe down what you can with tissue paper then soak it in simple green solution.

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[uncfnp]

Hot water and a tooth brush worked best for me. That stuff is awlful! Oh, not sure how much it helped but used Dawn dish liquid too

 

[NotSure]

I use a cotton rag and q-tips to remove as much silicon as possible. Don't even waste your time with cleaners until there is nothing but a light film left. Then you can soak in very hot water with simple green or dawn and scrub with a brush. After all that use your ultrasonic with fresh hot cleaning solution and repeat until there is no oily film on surface.

 

[halocline]

Count yourself lucky that you got a SPEC boot, those things are very hard to find. You might also be fortunate with the silicone; even though it's a pain to get out, (scrubbing with dish soap and hot water seems to work about as well as anything I've tried) every MK 5 or 10 that I've ever bought with silicone packed in the chamber has been pristine, despite not being rebuilt for who knows how long. That silicone is very protective as long as there are no voids.

As I mentioned in another thread, I pack mine with PTFE grease these days, but when I run out I'll go back to silicone.

 

[rhwestfall]

... every MK 5 or 10 that I've ever bought with silicone packed in the chamber has been pristine, despite not being rebuilt for who knows how long. That silicone is very protective as long as there are no voids.

not so lucky... there is a very slight beginning of corrosion on the spring, that transferred (hoping color only) to where is sat on the piston....

it's not bad, but not pristine....

 

[dberry]

Okay, offering advice here as a chemist with fair amount of experience in silicone chemistry, but no regulator specific experience. Silicone grease (polydimethylsilicone) is virtually impervious to neutral or weakly acidic aqueous solutions. Basic (alkaline) solutions, preferably in alcohol, can be very effective (and are what we use in lab to remove silicone grease from glass joints and such. So, IF your regulator parts are ok with mild base, you could use aqueous sodium carbonate (automatic dishwasher powder) or TSP (trisodium phosphate) for an long soak after physically removing as much as possible. The most effective treatment would be to put some sodium hydroxide (lye) in rubbing alcohol (isopropanol)and let it sit for a day. Most of the lye won't dissolve, but the resulting isopropanol solution will definitely loosen the silicone grease quite effectively. Shouldn't bother most metal, but no promises about O-rings or rubber pieces. Good luck!

 

[DA Aquamaster]

It's not rocket science and it's not hard to remove. It used to be the norm for reg techs working on Scubapro regs before they switched to the TIS system.

As noted above, you'll want to use an alkaline cleaner like Blue Gold or Simple Green. After you wipe most of it out with a couple paper towels, you'll want to use one or the other cleaners diluted at 1-10 rather than the normal 1-20 or 1-30 ratios.

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Also as noted above, a properly packed ambient chamber and spring were very effective at preventing freeze flows, and for protecting the chamber itself. Unfortunately, not all techs packed them properly. You have to start with by packing the spring around the piston stem and head as well as packing the inside of the chamber itself, so that there are no voids that might allow water to contact the metal parts.

The problem with a poorly packed chamber is that those voids can trap water against a metal surface and cause rust or corrosion over the long term.

 

[rhwestfall]

here's the results of a crappy packing job:

 

[Centrals]

Okay, offering advice here as a chemist with fair amount of experience in silicone chemistry, but no regulator specific experience. Silicone grease (polydimethylsilicone) is virtually impervious to neutral or weakly acidic aqueous solutions. Basic (alkaline) solutions, preferably in alcohol, can be very effective (and are what we use in lab to remove silicone grease from glass joints and such. So, IF your regulator parts are ok with mild base, you could use aqueous sodium carbonate (automatic dishwasher powder) or TSP (trisodium phosphate) for an long soak after physically removing as much as possible. The most effective treatment would be to put some sodium hydroxide (lye) in rubbing alcohol (isopropanol)and let it sit for a day. Most of the lye won't dissolve, but the resulting isopropanol solution will definitely loosen the silicone grease quite effectively. Shouldn't bother most metal, but no promises about O-rings or rubber pieces. Good luck!

Potassium hydroxide in ethanol is great to remove silicone grease from glassware. I am pretty sure it etches away the glass as well. Sodium hydroxide in propan-2-ol is milder, I believe.