250 watt DE MH bulb question

[greg1786]

Ive been running MH on my systems for a long time. After a 3 year hiatus I recently set up my 125 again. During the process I needed to do some maintenance on my halide fixture. It house 3x 250w DE mh bulbs and 2x 150w DE mh bulbs. Theere were 3 ceramic end caps for the 250s that I replaced because the metal connectors were a little coroded or just not looking good. Anyhow I am replacing the bulbs slowly now and I put a new 250 watt bulb in today and it was very rigid trying to snap it in place. In the passed I've never had quite as tough a time almost to the point I was concernes I may bend the little metal connector in the end cap. So my question is simple, is there a lubricant available that can be used to make replacing DE mh bulbs a little smoother ? I know theres a ton of light bulb grease out there but unsure if any is ok to use with MH given the heat they produce. Thanks in advance
-Greg

 

[A. grandis]

I don't have an answer for that!
This is very interesting!!
One of the reasons I don't play with double ended bulbs id because of that.
Never heard of any lubricants for sockets.
If were me I would simply clean the metal with WD40 and dry with a cloth before install the bulb. Would I be ok doing that?
WD40 is a cleaner, not a lubricant. I don't know if I would want a lubricant per say in that part of the fixture.

Hopefully an expert will show here to give tell us the right way to do that, if there is.

Grandis.

 

[greg1786]

I don't have an answer for that!
This is very interesting!!
One of the reasons I don't play with double ended bulbs id because of that.
Never heard of any lubricants for sockets.
If were me I would simply clean the metal with WD40 and dry with a cloth before install the bulb. Would I be ok doing that?
WD40 is a cleaner, not a lubricant. I don't know if I would want a lubricant per say in that part of the fixture.

Hopefully an expert will show here to give tell us the right way to do that, if there is.

Grandis.

Yea the metal seems like it has to much friction when you try to press them in. The connector inside the ceramic end cap is held closed by a u shaped prong so that the metal connector on the bulb is held nice and snug. Its always needed a little effort to get them in place but this recent one was very difficult. As far as WD40 goes that is a good idea and I am curious the answer. I'm no more confident to use that without some "professional" advice than I am with the grease or lubricant. There a lot of different bulb lubricants available especially in the auto industry. Most halogen light bulbs used in headlamps for vehicles suggest using the grease to allow the bulb easier penetration into the socket. My main concern though remains, for our halide application, that the heat is so intense in our fixtures I am worried of fire or at the very least sparks and failure.

To give you an idea of how hot they can actually get, especially when there is something wrong ill attach a picture of what was left from the connector on a 250w DE bulb that sparked and almost caught fire in my fixture because it wasn't seated properly.

 

[A. grandis]

Yeah, they can get really hot!!
I didn't know they actually make bulb lubricants.
That is great!
There are lot's of guys that come here and know a lot about halides. Let's just wait then...
Grandis.

 

[reefndude]

I've used spray silicone lubricant on t5 sockets before beacause they were sticking. Freed them up. I think it would be safe to use

 

[jda]

You can use electric grease if you want.

 

[A. grandis]

I was thinking about electric grease too.
I use it on outside outlets to avoid shots when it's too humid outside.
Grandis.

 

[dvbrien]

Dielectric grease

 

[greg1786]

Thanks for all the replies. I like the idea of electric grease. I'm not trying to discount anyone's suggestions in any way and I greatly appreciate any that are offered, but to those who suggested using any of the mentioned lubricants or greases, has anyone actually used them on a double ended 250w metal halide bulb successfully? Thanks again!
-Greg

 

[A. grandis]

Ok...
The Loctite dielectric grease states it can be used with up to +399°

"SPECIFICATIONS

• Brand: Loctite
• Loctite Number: LB 8423
• Chemical Base: Silicone
• Application: Electrical Equipment
• Maximum Operating Temperature: +399 °F
• Minimum Operating Temperature: -67 °F
• Package Type: Tube
• Package Size: 3 oz
• Color: Clear
• Volatile Organic Compounds (VOCs): 0 %
• Storage Condition: Store Away From Heat, Sparks and Open Flame; Store in a Cool, Well-Ventilated Area
• Package Quantity: 6 per case
• Former Name: Dielectric Grease"

FROM:
https://www.rshughes.com/p/Loctite-...5997!&ef_id=VQ6GPQAAAJFIMRMY:20180102030311:s

Now...
Some one once tested his 250W MH bulb for temp and found ~347°F running a magnetic ballast with enclosed canopy and no fans!!

"phoenix 14k 250w mogul
sunlight supply blue wave 1 m138 pulse start ballast
sunlight supply reef optix 2 reflector
craftsman digital multimeter with temp probe.
running 5 1/2 hours, enclosed canopy with no fans. 20h tank (24x12 if i remember correctly)
bulb 347f (man its hot checking the temp)
reflector 123f
air temp 6" from bulb 91f
water temp 78f
air temp 62f (tank is i the basement)
i have a 150w high bay halide but i cant get the glass off to check the temp. ill keep working on it to see if i can get a temp."
FROM:
https://www.nano-reef.com/forums/topic/239614-how-hot-does-a-metal-halide-light-get/

I guess it will depend on the set up, bulb and ballast combination you have, but for a 250W bulb, if the text above is true, the grease wwould work.
The Blue Wave ballast is already hot and will drive the bulb hotter than electronic ballasts.

I would just make sure the grease does a lubricant job and remove the excess and see no problem. Let us know...
Grandis.

 

[dvbrien]

You can get dielectric Grease from Napa, Autozone, Pepboys, Advance Auto or any other autoparts stores. The sell it specifically for bulb installations.

 

[A. grandis]

Home Depot also has it!
This brand claims that can be used up to 500°F!

"Super Lube Silicone High-Dielectric & Vacuum Grease - 3 oz tube. Non curing Silicone compound. Temperature range from -40 degrees F to +500 degrees F."
The label says up to +400°F though.
FROM:
https://www.homedepot.com/p/Super-L...e-Hi-Dielectric-Vacuum-Grease-91003/202932695
Grandis.

 

[greg1786]

Ok so that sounds like it could work! My fixture is free hanging with no canopy or cover so the heat dissipates quickly. I will head to HD or the auto store tomorrow and pick some up. I don't have any bulbs to change currently but will take the new one out, grease it, and slip it back in so we can see how it does. Ill update the thread tomorrow with photos and such after I'm done. Thanks again guys! Grandis nice job on the research!!

 

[dvbrien]

Bro, grease the fixture. Not the bulbs... unless you're looking for excitement.

 

[greg1786]

Bro, grease the fixture. Not the bulbs... unless you're looking for excitement.

Lol I may have been a bit misleading in that post. I know not to grease the bulbs, when I said that I was referring to the metal connectors at the ends of the bulb which slip into the metal connectors in the ceramic end caps located in the fixture. Sorry for the confusion

 

[A. grandis]

Yeah, put just a bit on the metal and wipe the excess off.
Grandis.

 

[jda]

Some of them came with it on them when they were new. A spot the size of a BB is enough.

The bulb is supposed to be a little hard to get in. I have use the butt end of a hammer (wood part) to press them in before when my thumbs would not get it done.