question about glass pane and light loss - Growroom Lighting - International Cannagraphic Magazine Forums

valk · 12-15-2004, 06:43 AM

I'm putting the finishing touches on my 3x3x6 box. I'm about to mount my light on the top (outside) of the box. I used a router to create a nice recessed lip in the top for the light to sit on.

My concern is that this won't be air tight and smell will get out. I was thinking of caulking a piece of glass in that space then sitting my light on top.

Would there be any problems with a double layer of glass like that?

12-15-2004, 07:08 AM

There is a reduction factor with glass and pyrex, so the thicker and more you use the more light intensity you block, larger bulb's it might not matter as much with smaller one's. I would put the glass in the box and seal it, then set the hood wit out glass on top of that, all should be good to grow.

grow safe.

realhigh.

Mr GreenJeans · 12-15-2004, 08:42 AM

valk
For hot applications a contractor friend of mine uses a product called Sikaflex. It comes in a large cartridge just like caulking. I've tried it for other things, and it does last a long time - my oldest application out in the yard - with full southern exposure - is still good after 2 years... Same price as a good weatherproof caulk. -MGJ

12-15-2004, 04:11 PM

But how well does it cut. If you seal the hood to the edge of wood over the piece of glass that you sealed in place, how do you change light bulb's or maintance the light???????????

Now seal the glass to the grow chamber, you keep all sealed as you wanted, now set the hood down over the glass, you do not need the galss in the hood. Now you want to seal the light leaks around the edge , use the aluminum tape, it block's out light just fine and handles heat of a lamp good also.

Time to change a bulb, remove the tape and hood, do what you need, set it back down and tape it up again. This will cost a lot less, is much easier to remover for maintance, and should do exactly as you want.

grow safe.

realhigh.

**Babbabud** · 12-15-2004, 05:14 PM

I would say if you dont use tempered glass this could be a dangerous set up. The tempered glass will put up with the heat alot better and if it does break somehow chances are it wont hurt anything... if you dont use tempered glass things could get very ugly

Just my .02

12-15-2004, 05:30 PM

That was a major over site on my behalf, and not good, Babbabud, you are so right, with the idea of a fixed piece of glass at top of the grow chamber, a crack or major miss happening while one is in the unit could be very dangerous, and we are not about risking our life's.

Glad you caught that one, it will cost a bit more, but you can order it to size and the local glass shop can get it to you. Not all but a few garden center's will order it for you also, but they just call the local glass house for it.

Remember you size bulb and how hot it get's, it is about 2 to 3 inch's above the glass.

tempered glass will also handle much more heat than regular standard glass, so do it right and order the tempered glass.

I have one hood with a tempered glass sheild, and one pyrex cool tube, and one hood with a 1/8th inch double strength standard glass shield. Do I notice a difference between them and the bud's, hummmm, not really at all, if there is it is nothing to talk about.

grow safe.

Happy Holiday's

realhigh

Mr GreenJeans · 12-15-2004, 07:52 PM

Good questions. The Sikaflex cuts very easy with a knife, it just doesn't split easily without one. I would think if you cauled on the outside rim edge of the glass you wouldn't need much, it would hold well, and you could easily slice into it if you need to later.

I'm going to do this with the light I'm picking up next week, for the same reasons. Smell control.

Cheers -MGJ

valk · 12-15-2004, 11:58 PM

Thanks for all the suggestions guys. I think I'm going to use realhigh's idea and just use the glass my hood came with (I'm assuming it's tempered enough) to seal into the recess using some Sikaflex. I'll just put the hood on top and seal it up with some foil tape. Thanks for all the great ideas!

12-16-2004, 02:05 AM

Most all tempered glass has rounded edge's to it and looks a bit different the cut edge of standard glass, and it weigh's a bit more than standard glass. I am not at all sure if hood's sold commercially come with tempered, but the piece I got was order and a part of Sun system's hood's, one of them.

If the weight of the hood is put on the glass, this is added stress that was not factor into the problem, if a piece of molding was used on the top side of the glass that the hood than restested on, well the recess cut would bear the weight of the hood.

Look at what you got, think it out, and I am sure you will come out just fine.

grow safe.

realhigh.

valk · 12-16-2004, 09:02 PM

Well, the outside perimeter of the hood has the metal folded under to create a lip for the glass to rest in. Setting the light on top of the glass would still have the recess cut supporting both the glass and light. I think this will work out nicely. Is Silkaflex rated for high temps? It looked like it was for marine applications to me...

12-15-2004, 06:43 AM	#1
valk Member Join Date: Oct 2004 Posts: 153	question about glass pane and light loss I'm putting the finishing touches on my 3x3x6 box. I'm about to mount my light on the top (outside) of the box. I used a router to create a nice recessed lip in the top for the light to sit on. My concern is that this won't be air tight and smell will get out. I was thinking of caulking a piece of glass in that space then sitting my light on top. Would there be any problems with a double layer of glass like that?
	Quote

12-15-2004, 07:08 AM	#2
Guest Guest Posts: n/a	There is a reduction factor with glass and pyrex, so the thicker and more you use the more light intensity you block, larger bulb's it might not matter as much with smaller one's. I would put the glass in the box and seal it, then set the hood wit out glass on top of that, all should be good to grow. grow safe. realhigh.
	Quote

12-15-2004, 08:42 AM	#3
Mr GreenJeans Sat Cat Join Date: Jul 2004 Location: Digging at an Arakeen Melange Blow Posts: 3,922	valk For hot applications a contractor friend of mine uses a product called Sikaflex. It comes in a large cartridge just like caulking. I've tried it for other things, and it does last a long time - my oldest application out in the yard - with full southern exposure - is still good after 2 years... Same price as a good weatherproof caulk. -MGJ
	Quote

12-15-2004, 04:11 PM	#4
Guest Guest Posts: n/a	But how well does it cut. If you seal the hood to the edge of wood over the piece of glass that you sealed in place, how do you change light bulb's or maintance the light??????????? Now seal the glass to the grow chamber, you keep all sealed as you wanted, now set the hood down over the glass, you do not need the galss in the hood. Now you want to seal the light leaks around the edge , use the aluminum tape, it block's out light just fine and handles heat of a lamp good also. Time to change a bulb, remove the tape and hood, do what you need, set it back down and tape it up again. This will cost a lot less, is much easier to remover for maintance, and should do exactly as you want. grow safe. realhigh.
	Quote

12-15-2004, 05:14 PM	#5
Babbabud Bodhisattva of the Earth Join Date: Mar 2004 Location: N. Cal Posts: 9,535	Glass I would say if you dont use tempered glass this could be a dangerous set up. The tempered glass will put up with the heat alot better and if it does break somehow chances are it wont hurt anything... if you dont use tempered glass things could get very ugly Just my .02 __________________ (Medical Patient In Compliance) Nam myoho renge kyo !! Mugi wasshin your bud babba Peace/ Be here now Babba's Farm L.L.C.
	Quote

12-15-2004, 05:30 PM	#6
Guest Guest Posts: n/a	That was a major over site on my behalf, and not good, Babbabud, you are so right, with the idea of a fixed piece of glass at top of the grow chamber, a crack or major miss happening while one is in the unit could be very dangerous, and we are not about risking our life's. Glad you caught that one, it will cost a bit more, but you can order it to size and the local glass shop can get it to you. Not all but a few garden center's will order it for you also, but they just call the local glass house for it. Remember you size bulb and how hot it get's, it is about 2 to 3 inch's above the glass. tempered glass will also handle much more heat than regular standard glass, so do it right and order the tempered glass. I have one hood with a tempered glass sheild, and one pyrex cool tube, and one hood with a 1/8th inch double strength standard glass shield. Do I notice a difference between them and the bud's, hummmm, not really at all, if there is it is nothing to talk about. grow safe. Happy Holiday's realhigh
	Quote

12-15-2004, 07:52 PM	#7
Mr GreenJeans Sat Cat Join Date: Jul 2004 Location: Digging at an Arakeen Melange Blow Posts: 3,922	Good questions. The Sikaflex cuts very easy with a knife, it just doesn't split easily without one. I would think if you cauled on the outside rim edge of the glass you wouldn't need much, it would hold well, and you could easily slice into it if you need to later. I'm going to do this with the light I'm picking up next week, for the same reasons. Smell control. Cheers -MGJ
	Quote

12-15-2004, 11:58 PM	#8
valk Member Join Date: Oct 2004 Posts: 153	Thanks for all the suggestions guys. I think I'm going to use realhigh's idea and just use the glass my hood came with (I'm assuming it's tempered enough) to seal into the recess using some Sikaflex. I'll just put the hood on top and seal it up with some foil tape. Thanks for all the great ideas!
	Quote

12-16-2004, 02:05 AM	#9
Guest Guest Posts: n/a	Most all tempered glass has rounded edge's to it and looks a bit different the cut edge of standard glass, and it weigh's a bit more than standard glass. I am not at all sure if hood's sold commercially come with tempered, but the piece I got was order and a part of Sun system's hood's, one of them. If the weight of the hood is put on the glass, this is added stress that was not factor into the problem, if a piece of molding was used on the top side of the glass that the hood than restested on, well the recess cut would bear the weight of the hood. Look at what you got, think it out, and I am sure you will come out just fine. grow safe. realhigh.
	Quote

12-16-2004, 09:02 PM	#10
valk Member Join Date: Oct 2004 Posts: 153	Well, the outside perimeter of the hood has the metal folded under to create a lip for the glass to rest in. Setting the light on top of the glass would still have the recess cut supporting both the glass and light. I think this will work out nicely. Is Silkaflex rated for high temps? It looked like it was for marine applications to me...
	Quote