well, i was going over the designs for my server rack enclosure, and it occurred to me, how do i seal around bundles of wires passing in and out of the enclosure. the ventilation system in my rack is negative pressure, and draws in through a filter. the enclosure is in my basement and there is a wood stove down there (ash dust), so the air coming in needs to be filtered. so what is the best way to non-permanently seal around the wires?
I was thinking of using just a tube, and pack shipping foam tight around the wires.
I was thinking of changing it to a positive pressure, negating the need to seal the wires, but the rack enclosure is mostly built, so it would be a major pain in the *** to change it now.
In situations where I needed a good seal against moisture saturated air I have used this:
if left in the package it also makes a great halloween costume accessory. Just buy a few and stick them in an old fishing vest with some wires inserted and viola!
Silicone sealant, as used around baths and sinks. It will smell of acetic acid (vinegar) for a day or two, as it cures.
Depending on the area to be sealed, you may have to apply it in stages. It it flexible once cured, so should allow for any slight bending of the wires.
travis_farmer:
I have used silicone sealant (though i prefer geocel). i was actually trying to find a less permanent option. where i can add or remove cables as needed.
Plumber's putty would be the less permanent option.
If you want permanent sealant for vacuum, get some vacuum sealant. Torr seal is one brand. It's not cheap. You mix the two parts, and apply over each wire, bundle them, make sure the gaps are filled with sealant, then seal the bundle on a tube or something that you seal to an access hole. Sounds good?
travis_farmer:
the enclosure is in my basement and there is a wood stove down there (ash dust), so the air coming in needs to be filtered. so what is the best way to non-permanently seal around the wires?
The usual way to seal around cable bundles is to use a rubber 'disk' with an X cut through the middle. It is not an air tight seal but it rarely needs to be.
I was thinking of changing it to a positive pressure, negating the need to seal the wires, but the rack enclosure is mostly built, so it would be a major pain in the *** to change it now.
In dusty environments positive pressure is usually more effective, as the outward pressure aids airflow through the chassis and pushes polluted air away from any vent in the cabinet. When I was building server cabinets for installation in industrial premises after a bit of experimenting, we ended up turning the fans over in the fan tray to create a top down positive pressure. In a really dusty environment, I would imagine the challenge would be filtering the inlet to the fan tray whilst maintaining sufficient airflow downstream.
