Beginners Guide to DIY Homebuilt Cannister Lights.

[mjcoussens]

I'm getting together all the parts to make this happen, but am having a hard time sourcing the 3" PVC pipe locally. Can I substitute the ABS pipe? I know they need different glues, but what I'd like to know is if I can heat it in the oven to create flat stock as mentioned with the PVC?

Thanks,

Matt

 

[mkutyna]

Doing a google search for "bending abs pipe" mostly brings up articles about bending PVC but they mention ABS as well so it seems that it is possible. To be safe, I'd start out 100 degrees lower and see how pliable the ABS becomes. If it's still too hard, up the temp in increments until you get the right temp.

I know prices in Hawaii can be high but you only really need to do tests on 2-3 inch segments before you dial in the correct temperature for bending ABS.

The other thing I'd check is the PSI rating for ABS compared to PVC. It should be similar though.

 

[mjcoussens]

Thanks, for the quick response. It never occurred to me to look up pipe bending, but it does seem that it's possible. I'll report back with my findings.

Matt

 

[jeraldjcook]

I just realized that there are 2 types of schedule 40 PVC, one that is pressure rated and one that isn't (only to used for vents, called cellular core). Turns out I bought the schedule 40 cellular core version. The wall thickness is the same, but it's lighter than the pressure rated version. Will the stuff I have work or do I need to return it? The pressure rated stuff is rate for 260psi, and I figure I'll only need 60psi for 130ft. Plus the pressure is different, compression vs. expansion. I'm starting to ramble so I'll end here. Thanks in advance.

Edit: Nevermind, I found this: http://www.scubaboard.com/forums/showthread.php?p=1599955&highlight=cellular+core#post1599955 Guess I need to return it.

 

[mjcoussens]

Well, after some more googling on the strength of ABS vs PVC here: http://tomacorp.com/ballistics/ABSvsPVC.html
It looks like ABS should be strong enough to withstand the pressure as well as being more impact resistant. I went ahead with the bending by using a foot long piece of 4" ABS pipe. Heating to 300F made it slightly pliable, 350F more so, however complete pliability to the point of being able to flatten it out happened when the temp was raised to 375F and held for 5 minutes. If I was going to do it again I think I would cut the pipe in half longitudinally beforehand to help avoid some of the "wrinkles that were formed in the center of my flat stock.

Additionally, the ABS comes in black so it's automatically DIR. Now, if I could only find some decals of Blue H's to stick on it...:canofworms:

Matt

 

[Hollywood13]

ok, this is annoying. The link worked fine yesterday but when I tried today so I could print it out, it doesn't work. It keeps saying, " This file is damaged and could not be repaired. " AAAAHHHHH

 

[cjfox]

I just finished my 2nd dive with my DIY canister light, and the MOSFET switch set up over heated and failed (would not shut off). When I bought the stuff at the electronics store, the guy said I would not need to heat sink it, but I'm thinking maybe I do. When I took it apart it was definitely burned. Any one else playing with this stuff?

 

[Packhorse]

I tried a MOSFET but found it heated up too much ( I had it in the canister)
So I just use a small 10amp relay instead.
No heat and very little current draw from the relay (maybe 50mamps or less).

Not sure of any MOSFET bebbifits unless you want to dim or otherwise control the bulb.

 

[mddolson]

Yes You can.
I did. I couldn't find a thick block to amchine the base, so I just used a plumbing cap.
Here's a link to my divelight & cannister.
I currently machining an aluminum cannister.

http://groups.msn.com/divelight/mikedshidlight.msnw

Mike D

I'm getting together all the parts to make this happen, but am having a hard time sourcing the 3" PVC pipe locally. Can I substitute the ABS pipe? I know they need different glues, but what I'd like to know is if I can heat it in the oven to create flat stock as mentioned with the PVC?

Thanks,

Matt

 

[mjcoussens]

Well, I've managed to finish the Illuminator this weekend using ABS pipe, and 12 D-cells over volting a 50watt Halogen. I have to say I'm impressed by the brightness and my wife was even more impressed at the build quality (apparently I have a reputation for Ghetto-rigging). BTW, I found that McMaster carries the same Nielson Sessions latches as Salvo that were mentioned in the guide. If anyone has trouble getting the guide or needs part numbers for any of it feel free to pm and email address to send it off to.

Matt