Waterproofing a light?

[fre1102]

Just changed the bulb a Pentair 7845100--the 'pool light' I see in everybody's pool. 500W, etc., etc.

It's leaking. This has never happened before. Is there's a 'trick' to this I don't know about?

 

[1poolman1]

Just changed the bulb a Pentair 7845100--the 'pool light' I see in everybody's pool. 500W, etc., etc.

It's leaking. This has never happened before. Is there's a 'trick' to this I don't know about?

Did you replace the gasket? It should be done every time a light is opened unless it is a silicone gasket. How tight did you close the clamp? The loops should be touching when you are done. If all that was done it is probably leaking at the cord entrance and needs to be replaced.

 

[fre1102]

. How tight did you close the clamp? The loops should be touching when you are done.

TOUCHING?

They're definitely not touching--they're about an inch apart. But they've always been about an inch apart.

The two ends should be touching? Crank it down that hard?

 

[1poolman1]

TOUCHING?

They're definitely not touching--they're about an inch apart. But they've always been about an inch apart.

The two ends should be touching? Crank it down that hard?

When the light comes from the factory, the loops are touching. If you can't get them to touch, get them as tight as possible using two wrenches. If yours weren't a bulb was probably replaced in the past and someone got lucky. Don't forget the "new gasket" part.

 

[fre1102]

When the light comes from the factory, the loops are touching. If you can't get them to touch, get them as tight as possible using two wrenches. If yours weren't a bulb was probably replaced in the past and someone got lucky. Don't forget the "new gasket" part.

I cranked it down and it seems to be watertight.

About the 'new'--is that literally EVERY opening? It was new earlier today, but has now been installed the first time, then removed when it leaked, then reinstalled. Replace it?

 

[nuttyp]

The instructions I found for that Pentair light here say 1/4" gap or less for the unitension clamp. Worth reading thoroughly. Didn't know new ones come with clamp ends touching - interesting. Use of an aftermarket knockoff gasket has also bitten people. Some gaskets are marked "this side facing pool", easy enough to install backwards, not sure about this one. In addition to what others wrote, test and verify it's on a working GFCI breaker (test button and/or other methods to verify small leakage current will trip breaker). Be meticulous - all gasket contact surfaces undamaged and spotless - zero calcium or other crud. Instructions do not say either way about whether to coat surfaces with lubricant (could call & ask Pentair) - if using lube use non-petroleum based lube, eg jacks, lubetube, etc. I always use Jacks and never returned to one that leaked, perhaps just lucky. I coat all surfaces - very lightly - including the inside of the clamp so it compresses evenly without clamp or gasket hanging up. Don't know what to say about the literal interpretation of "new gasket every time you re-open it" like a day later. Interesting discussions in other/older TFP threads such as this one 9 years old. Good luck.

 

[1poolman1]

I cranked it down and it seems to be watertight.

About the 'new'--is that literally EVERY opening? It was new earlier today, but has now been installed the first time, then removed when it leaked, then reinstalled. Replace it?

If the light hasn't been used "much," the gasket you have should be OK. I never took the chance when replacing a bulb for a customer.