How much silicone to use ?

[lmorin]

On o-rings for dive lights or camera cases, how much silicone grease is optimal? Thanx.

 

[roakey]

The ring should be shiny, no more than that.

Roak

 

[DA Aquamaster]

Put a small amount on your finger tips and rub the o-ring between. You want enough to work it into the pores in the o-ring, but not enough to actually be able to see any excess on the surface.

 

[herman]

The key here is to understand that the silicon is a lubricant and is not actually part of the seal. It allows to O-ring for slide over the sealing surfaces without binding. The O-ring only needs enough silicon to allow it to slide into place. Without the silicon, the O-ring would tend to roll or pinch instead of sliding, causing gaps in the seal. I do like to lightly coat the mating surfaces on items that require the O-rings to slide a long distance. Flashlights that turn on by rotating the lens for example. This keeps from wiping off all of the silicon in the first few turns of the lens causing the O-ring to bind farther down. In any case, too much is never a good idea.

 

[lmorin]

Thanks for the info. I thought I did it right on the first dive with a my first light, a brand new present from my daughter that never left my pocket. Destructo. Came up oozing an impressive amount of black stuff. Chemistry is amazing.

 

[Bob3]

Keep an eye on those lights in the pocket, they can turn themselves on when at depth if you have the head screwed in too far.

 

[av8er23]

Where is the best place to get this once my little tube runs out? Do most hardware stores carry it?

 

[DA Aquamaster]

You want to be careful what you use. Most dive shops carry silicone in either a small tube or small 2 oz tub.

However, some camera o-rings are actually made out of silicone and using a silicone grease on them will cause them to expand. That can get expensive when your camera floods. So with a camera, I always use whatever the housing manufacturer suggests.