will grease soften rubber?

DXN

Petty Officer 2nd Class
Joined
Jun 21, 2013
Messages
120
I check over my bellows regularly, so I know there was no previous damage. When I greased everything some squeezed out and got on the bellows. After 2 trips I noticed the grease spots a little chafed. The rubber is very soft where the grease was and I could probably punch through it with a small stick. I used generic marine grease from O'Rylie's.
 
Joined
Feb 17, 2012
Messages
2,906
Re: will grease soften rubber?

yes grease which is oil mixed with a thickening agent does not play well with rubber. Not all rubber is made the same way with the same additives so some are affected worse that others the same as different brands of grease may react differently.
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
Re: will grease soften rubber?

the INSIDE of the drive shaft bellows is very often heavily coated with grease slung from the u joints and gimbal bearing with no ill effects

the grease SHOULD not hurt the bellows at all... I suggest that maybe the bellows are just old and need replaced (should be replaced every few years)... possibly the grease created a clean spot by softening some oxidized rubber???
 

DXN

Petty Officer 2nd Class
Joined
Jun 21, 2013
Messages
120
Re: will grease soften rubber?

Ahhh I think your on to it smoke. The rest of the bellows is a little stiff feeling. And I was thinking they didn't have allot of life left, that's why I check them so often.

Thanks this makes sense now.
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
Re: will grease soften rubber?

if that's be the case then go ahead and replace em BEFORE they sink your boat.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,544
Re: will grease soften rubber?

General Characteristics of Common Polymers from The Rubber Group

This is a thread about Neoprene rubber and if you read the comments at the bottom of that column you will get your answer. I would assume that any rubber product that is used in a marine environment would be of silicon or neoprene for the reasons stated. It's been many years since I had an I/O and changed out the bellows so I can't say much about it; other than it was one !@#$%^ of a job.

Mark
 
Top