Hi guys,
I am still researching the care and feeding of VMQ (RED) silicone seals as supplied in R&R Water Tight Cylinders.
New Info:
Every resource I find on the internet warns that VMQ Silicone O-rings have Poor Mechanical Strength: They have low tensile strength, poor tear resistance, and high friction. They are generally unsuitable for high-pressure, high-wear dynamic sealing (moving parts). Because of these characteristics, VMQ O-rings are primarily used in static seals (stationary applications).
Ron’s WTC’s use a tiny (4mm I.D.) O-ring to seal the prop driveshaft. This is the seal that keeps the water out of the aft electronics compartment. The high friction with the spinning propshaft causes extra strain on the motor. This adds to excess heat and battery drain.
On 6/22/2026 Forum member Subculture posted:
“I've never had an issue with O-ring glands. They work well enough especially if not going for very high-speed drive. They're more common in the UK because O-rings were simply a lot easier to source and even those could be hard to find in certain sizes- it was really difficult finding stuff for this hobby before the internet opened up supply chains. The builders of much legacy hardware stick with what is tried and tested.”
Thanks, Subculture. Perhaps I am just 'chicken little', bleating that the sky is falling. I did note that Bob Martin just listed for sale a new 4mm shaft-seal setup for the R&R cylinders. Thanks again Bob for listening and being responsive to your customers.
Testing known information:
I can verify that using a silicone-based lubricant will cause the VMQ (RED) silicone seals to swell and get sticky to the touch (partial breakdown and liquification).
I purchased a supply of identical 70mm O-rings to renew the seals on my WTC. When a fresh O-ring is placed next to one that I had coated with Permatex O-ring lubricant (a silicone-base lubricant), the coated O-ring grew larger, became softer and quite tacky.
The internet advises they must only be lubed with a thin coating of Fluorosilicone or PTFE (Teflon) Based Greases. The Teflon greases I am finding on the internet uses a base lubricant that is either silicone or petroleum-based. The Fluorosilicone grease is $129.00 USD for a 100mm tube!
(Help!) Guys, what brand/product do you recommend that is safe for the O-rings Ron puts in his WTC’s?
I am still researching the care and feeding of VMQ (RED) silicone seals as supplied in R&R Water Tight Cylinders.
New Info:
Every resource I find on the internet warns that VMQ Silicone O-rings have Poor Mechanical Strength: They have low tensile strength, poor tear resistance, and high friction. They are generally unsuitable for high-pressure, high-wear dynamic sealing (moving parts). Because of these characteristics, VMQ O-rings are primarily used in static seals (stationary applications).
Ron’s WTC’s use a tiny (4mm I.D.) O-ring to seal the prop driveshaft. This is the seal that keeps the water out of the aft electronics compartment. The high friction with the spinning propshaft causes extra strain on the motor. This adds to excess heat and battery drain.
On 6/22/2026 Forum member Subculture posted:
“I've never had an issue with O-ring glands. They work well enough especially if not going for very high-speed drive. They're more common in the UK because O-rings were simply a lot easier to source and even those could be hard to find in certain sizes- it was really difficult finding stuff for this hobby before the internet opened up supply chains. The builders of much legacy hardware stick with what is tried and tested.”
Thanks, Subculture. Perhaps I am just 'chicken little', bleating that the sky is falling. I did note that Bob Martin just listed for sale a new 4mm shaft-seal setup for the R&R cylinders. Thanks again Bob for listening and being responsive to your customers.
Testing known information:
I can verify that using a silicone-based lubricant will cause the VMQ (RED) silicone seals to swell and get sticky to the touch (partial breakdown and liquification).
I purchased a supply of identical 70mm O-rings to renew the seals on my WTC. When a fresh O-ring is placed next to one that I had coated with Permatex O-ring lubricant (a silicone-base lubricant), the coated O-ring grew larger, became softer and quite tacky.
The internet advises they must only be lubed with a thin coating of Fluorosilicone or PTFE (Teflon) Based Greases. The Teflon greases I am finding on the internet uses a base lubricant that is either silicone or petroleum-based. The Fluorosilicone grease is $129.00 USD for a 100mm tube!
(Help!) Guys, what brand/product do you recommend that is safe for the O-rings Ron puts in his WTC’s?