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Fixtures for mercury vapor bulbs?

Posted: Sun May 26, 2019 12:25 pm
by Cowrie
Some sources I've encountered online claim that mercury vapor bulbs shouldn't be used with porcelain domes, only wire dome fixtures, even if the porcelain dome would be big enough to fit the bulb. Is this true, and if so, why is this the case.

Re: Fixtures for mercury vapor bulbs?

Posted: Mon May 27, 2019 1:39 am
by kingofnobbys
It needs to be a fitting capable of withstanding high temperatures and the MVB wattage : a full ceramic fitting is required for any MVB.
https://www.nettopet.com.au/urs-flat-ce ... gIS7PD_BwE
https://www.mypetwarehouse.com.au/urs-l ... ng-p-15317
These are readily available from pet shops who sell lighting .

Regarding domes : as in reflector domes - I've not seen porcelain DOMES , all the ones I've seen sold for reptiles are made of pressed aluminium or steel sheet.
http://www.exo-terra.com/en/products/glow_light.php

The idea of the reflector dome is to redirect the UV downwards where you need it and it's the most beneficial to the reptile. A reflector dome will essentially double the penetration power of the UV from a given UV source (MVB).

The idea of the metal cage surrounding a MVB (or other basking globe) is to stop a reptile from making direct skin contact with the glass surface and suffering terrible burns.

Re: Fixtures for mercury vapor bulbs?

Posted: Mon May 27, 2019 5:56 pm
by Cowrie
With this new information, considering what I read was from an online store, I suspect they just may have been trying to drum up sales. So, just to be clear, a dome like that Exo-Terra clamp lamp would be suitable, right? I mean, it says the socket is porcelain, that's a type of ceramic.

Re: Fixtures for mercury vapor bulbs?

Posted: Tue May 28, 2019 3:45 am
by kingofnobbys
https://www.youtube.com/watch?v=2ZraKiKFtCY

IMO a reflector dome is optional , it will focus the UV , and make the beam of UV from the MVB narrower , bare in mind the metal dome will GET HOT !!!

I don't trust clamp lamps , the clamps have a habit letting go and the result can be desasterous .

Re: Fixtures for mercury vapor bulbs?

Posted: Fri May 31, 2019 5:20 am
by splashy07
Yes, the clamp type would be fine, just do not use the clamp. Remove it and set the lamp on the screen. As previously said, those clamps can slip and let go.
I used those type lamps for many years when I was still using glass terrariums. Just be certain the socket is ceramic, get the largest one you can and make sure it can handle high wattage. Wish we were neighbors, I have a closet full of them.

Re: Fixtures for mercury vapor bulbs?

Posted: Fri May 31, 2019 9:10 am
by kingofnobbys
splashy07 wrote:Yes, the clamp type would be fine, just do not use the clamp. Remove it and set the lamp on the screen. As previously said, those clamps can slip and let go.
I used those type lamps for many years when I was still using glass terrariums. Just be certain the socket is ceramic, get the largest one you can and make sure it can handle high wattage. Wish we were neighbors, I have a closet full of them.


Yep , have a stash of them too , I only your one dome these days , was originally a clamp lamp , I use it now hung under an adjustable lamp stand for when my big pet lizards are freeranging so they can recharge under basking globe .
Got a box full of spare domes & clamps .