Air Gap Installation


Old 06-08-16, 12:32 AM
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Air Gap Installation

Installing 'ol air gap for a dishwasher. Instructions state to put rubber gasket on bottom of counter and let plastic base rest on top of counter.

This seems counter intuitive, except.....Putting the rubber gasket on top makes the air gap sit high exposing both the white plastic base and the gasket.

Am I missing something, it's bad enough the white shows on a granite counter top, but putting the rubber gasket on the bottom of the counter would just trap water in the hole of plywood the granite sits on
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Old 06-08-16, 01:50 AM
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The rubber gasket should go under the counter, it looks better than on top of the counter.
If you have a tight fit water should not intrude. You can always place a very thin bead of silicone around the top nut if you're concerned with water.
As far as the white nut showing, you will need to shop for a new air gap if desired.
There are air gaps to where the cap covers the entire nut rather than sitting on top of the nut flange.
You should be able to find one at the big box stores.
Old 06-08-16, 10:41 AM
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The flange of the air gap needs to be set in a bed of plumber's putty, if you have natural stone counters be SURE to use a stainless putty even though the cost is about five times that of the regular putty. The putty seals the top from any water intrusion from the counter. While silicone sealant may be used it will make it very difficult to remove the air gap assembly if that is ever needed.

The rubber gasket goes under the counter and there should be a stiff paper gasket that goes between the rubber and the flanged nut. The paper is to allow the nut to slip on the rubber while tightening. Tighten it down until it is tight and then remove all the putty that squeezed out from the flange.
Old 06-11-16, 12:43 AM
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Temporarily installed el cheapo air gap, have nice one coming via amazon. No white ring (plus matches the sink/faucet better).

Picked up some

Oatey 9 oz. Stain-Free Plumber's Putty-31177 - The Home Depot

Thanks for the feedback....
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