o-ring question for 150 substrobe

[cfcstl]

I recently purchased a used 150 from someone not familiar with underwater photography equipment and I noticed the o-ring that seals the flash head to the body was an unusual shape. I have two other 150s and both of those o-rings are the same. This o-ring was thicker in diameter on the inside edge of the o-ring and tapered down in diameter toward the outside edge of the o-ring. The inside thickness was thicker than the normal thickness of the o-rings on my other strobes. It was very had to close the side clamps and I really didn't want to force them down. I replaced this o-ring with one of my other ones and the strobe clamped down like normal.

Does this o-ring configuration sound familiar? It seems to be the right size for this strobe but it seems too thick, at least on the inside edge.

 

[Ikelite Staff]

A very long time ago we used an o-ring instead of the flat lathe-cut ring. Perhaps if this took a set it would look the way you're describing. Regardless, the standard #0137 sealing ring is still available and would work properly on any age of strobe.

Aside from the sealing ring we have no parts remaining for these strobes so repairs, testing, etc. is impossible.

Regards,
Jean / Ikelite
IKELITE Underwater Systems

 

[cfcstl]

I can state that the ring is definitely lathe cut. After taking a very close look at both rings my initial description is a little off. I measured the original ring and it is about .150" in thickness. Actually it does not taper off as I stated originally, it does have a flat surface until the very outer edge then there is a bevel which makes the outside edge look a little thinner. I also measured the ring that does fit well and it is about .105" in thickness. It also does have a very slight bevel at the out edge but not real noticeable.
I tried to upload a macro of the two rings to show a comparison. I am really just curious as to the reason for the difference in size of the o-rings. Could this be an example of a swollen ring from improper o-ring grease?

 

[Ikelite Staff]

It's really impossible to say at this point... I know there was a dimensional change back in 2001 but don't have any information on the actual change that was made. 0.150" is the most up-to-date thickness specification on that part.

Regards,
Jean / Ikelite
IKELITE Underwater Systems