sealing nav lights

[BogMonster]

Not really sure if this should be in here or in electronics but they ain't electronics so here goes

I've just got new Aquasignal nav lights to be fitted to the lighting mast I have to fit to my RIB.

What's the verdict on whether to completely seal these as far as possible, or whether to leave drain holes at the bottom? The front mounting bicolour has what appears to be a drain channel in the bottom so I have left that clear, and the top mounting white all round light has three extra little holes in the base which seem to have no function, so I'm not sure whether these are supposed to be drains.

My feeling is to seal up any extra holes but I'm not sure if there could be a condensation build up inside the light if I do this?

Any thoughts on whether sealed or unsealed is best would be appreciated...

Ta

Stephen

[jyasaki]

Run them for a while to dry the air (assuming they get warm), then I would vote to seal them up. Either that or open them up and liberally spray anything metal with an anti-corrosion spray. Even if liquid seawater stays out, the salt air will eventually eat any exposed metal.

jky

[BogMonster]

Originally Posted by jyasaki

Run them for a while to dry the air (assuming they get warm), then I would vote to seal them up. Either that or open them up and liberally spray anything metal with an anti-corrosion spray. Even if liquid seawater stays out, the salt air will eventually eat any exposed metal.

They are both brand new lights and still nice and dry because I decided to do the wiring in the house and then mount the mast on the boat, on the basis it is 2*C outside at the moment and the house is a bloody sight warmer

I suppose sealing everything up where they fit on, then taking the lenses off, liberally spraying everything with WD40 and then reassembling would be the best answer then. My main concern was that expansion and contraction of air would eventually draw moisture inside and then it would have nowhere to escape, but I suppose a blast with a hot air gun and some WD40 every six months will probably do the trick. I don't expect to be using the lights much, the mast is mainly for a VHF aerial and so lack of use will be the main enemy.

Thanks

[psychopic]

Originally Posted by BogMonster

They are both brand new lights and still nice and dry because I decided to do the wiring in the house and then mount the mast on the boat, on the basis it is 2*C outside at the moment and the house is a bloody sight warmer

I suppose sealing everything up where they fit on, then taking the lenses off, liberally spraying everything with WD40 and then reassembling would be the best answer then. My main concern was that expansion and contraction of air would eventually draw moisture inside and then it would have nowhere to escape, but I suppose a blast with a hot air gun and some WD40 every six months will probably do the trick. I don't expect to be using the lights much, the mast is mainly for a VHF aerial and so lack of use will be the main enemy.

Thanks

i personally don't like sealing the units completely, as if water does get in it can never get out, maybe causing more damage.

[DJL]

I found sealing them was better than leaving them open to drain.

I also coated the copper in Quicksilver corrosion guard, again I found that to be better than WD40 (I think WD40 had an effect on the life of the plastic)

You could stick a small bag of Silica Gel in the lights to suck up any moisture in there.

[jyasaki]

Originally Posted by BogMonster

They are both brand new lights and still nice and dry

The moisture that would cause a problem is in the air, not the lights (well, I suppose the air is in the lights, so...)

I suppose sealing everything up where they fit on, then taking the lenses off, liberally spraying everything with WD40 and then reassembling would be the best answer then.

WD-40 would work, but is not the best solution. WD-40 leaves a very thin film of some kind of lubricant; what you want is a thick waxy layer of stuff. Most industrial corrosion inhibitors will leave this type of film.

I like the Boeshield T9 product, though some complain that it goes on too heavy. For most applications, where the object is out of sight, I don't see that as a problem.

My main concern was that expansion and contraction of air would eventually draw moisture inside and then it would have nowhere to escape

What I've seen is that, in ventilated situations, the moist air comes in, condenses, and stays trapped. Sealing it allows for a great deal less air transfer, thus less moisture overall. Add a thick film barrier on all exposed metal, and that's about all you can do short of filling the fixture with epoxy (or getting someone to recreate all tha metal bits with stainless.)


jky

[BogMonster]

Most of the time it will be out of the water so the condensation will not be salty, it should be no worse than vehicle lights and they usually last 5-10 years. I suppose the answer is to have the lights on all the time when I am out in it.... so they are dry inside when I recover it.

Thanks for the input