Has anyone made a bulkhead using standard plumbing fittings?

Kaos

"Lurker"
I'm getting ready to drill a 20L to make it rr and was wondering if I could use a MPT x slip adapter and a 90* slip x FPT elbow instead of haveing to order a bulkhead fitting. I figure I will put the elbow inside the tank and have the MPT x slip adapter going through the hole I'll drill in the glass and into the FPT portion of the elbow. I plan on using either silicone or o-rings to prevent leaking.

So, will this work? Has anyone else tried it? If so, how has it worked out for you?

I just can't see paying $7-$10 for the bulkhead fitting and then paying $10 just to have it shipped to me when I can spend less than $2 at Lowes for standard plumbing fittings and get the same results.
 

Kaos

"Lurker"
Here is a very "rough sketch" of what I'm talking about for people who are like me and do better w/ pic's then descriptions.



plumbingscheme.jpg
 

bkwudzjeep

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That is what I used for my bulkheads for my overflow box a while back. ...it worked fine.

I got the pieces from the electrical section at HD.....sch80 gray PVC I believe.
 

Kaos

"Lurker"
What did you use to seal it? I'm thinking of using some teflon tape on the threads and either silicone or an o-ring between each fitting and the glass.
 

bkwudzjeep

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It was just the o-ring against the acrylic (make sure it fits snug), and teflon tape on the threads.

The only difference was that mine was a straight drop and not an elbow, but I don't think it would be that much of a difference.

Maybe some others will hop in here too.
 

Kaos

"Lurker"
bkwudzjeep: Thanks allot, you've eased my mind some. How long did you have the system running like that? I'm just curious to see if I will have any trouble over the long term.
 

rji1966

New member
I have done this mutliple times without any problems. I usually had to cut a 1/4 - 1/2 inch off the theads of the male connector so that when I screwed the two pieces together they would tighten easier. I have done this on 1/4 plate glass tanks (29 gal and 30 gal) and a 125 gal. I would use silicon on the threads and then a bead around the connector on the inside of the tank.
 

Kaos

"Lurker"
rji1966: Thanks. I like the silicone on the threads idea. I was also looking at the threads and wondering if they would tighten down enough. I think I may take some off also.

Does anyone see a problem w/ using 1/2" pipe for all this? I don't plan on haveing more 200 gph for flow. I may also incorporate a closed loop that will also be 1/2" and will not exceed 350gph. Suggestions, opinions, experiences greatly appreciated.
 

bassnman11

New member
The electrical conduit fittings will tighten down because the threads are straight. Regular pvc fittings have tapered threads and may not tighten enough. A search of the plumbing dept will usually supply a gasket that will work.
 

brackishdude

New member
I could not find flat gaskets at either box store, just the round O rings, which made me a bit nervous about the thing rolling out. In the plumbing section I found 1/8" thick rubber sheets about 6x6", toilet-plunger red orange colored.

Just cut a sqare off bigger than needed, and keeep shaving off of the hole you cut in the middle until it sits snugly without deforming at the base of the flange on the male piece.

Good luck
 

BeanAnimal

Premium Member
I am not sure why anybody would go through all the trouble. Bulkheads are cheap, have a large wide gasket and a lot of surface area to cover the hole and help distrubute the stress of the plumbing. Secondly, threaded PVC fittings are tapered (NPT) that means that you may have trouble getting the threads to seal due to the thickness of the glass (either making the threads to loose or too tight).

Why re-invent the wheel when it is so cheap to begin with.

Bean
 

Kaos

"Lurker"
Thanks for the ideas.

BeanAnimal: As I said in the begining I can't see spending just as much on s/h as I'm paying for what's being shipped. I can get something thast will work just as well at Lowes for two bucks. Just hand tightening the MPT and FPT together I can get it to w/in 3/16" of being flange to flange. My tank glass is 3/16" thick. By the time I add o-rings or cut some rubber to make a gasket I will easily be able to tighten it up. And if I can't then I can just get rid of some of the threaded end (I've done it a hundred times w/ screws). I doubt on the bulkheads the flange is taking that much stress away from the glass. The fraction of an inch difference between the bulkhead and the standard plumbing fittings will not make that much difference. And if it does I can put an acrylic washer in there and kill two birds w/ one stone (make the surface area bigger and make it so I don't have to cut any threads off). I'm really not trying to argue, just to get you to see what's easier for some may not be easier for others.
 

BeanAnimal

Premium Member
Ahh no problem at all... I was just offering my .02 :)

I like ot DIY stuff and would do what you are suggesting if I had no other option... I take the trip to the store, the time and the hassle into consideration as well. I would rather spend the time, money and energy on a ig project or something that I can't afford to buy. Everybody likes to do things differently and I am sure that you can get your setup to work as you expect it too!
 

Kaos

"Lurker"
I value everyones opinion because it helps me find potential faults in my designs (which is why I post most all of them). If I had a LFS or store that sold bulkhead fittings then I would definitely go that route. DIY is about the only way us working stiffs can afford this hobby. And it makes me feel good when something that I came up w/ (or read about) works. One day I wouldn't mind building an entire setup from scratch. But that won't be anytime soon. I can't help it, I like bucking the system and I like building stuff myself. And I can't help myself from modifing something. Even if it works perfectly I can't stop myself from trying to tweak it if I can.
 

twon8

Formally registered membe
i did just what you are doing, except i used a threaded ball valve instead of the elbow. used a ? for a ring on the inside, and silicone on the outside. has worked fine for nearly three years.
 

energy_crisis

New member
I just did the same thing for my external overflow for my 70g...I wanted the external overflow to be as low profile as possible...bulkheads would extent the overflow box too much.

I used a 1.25" MTP w/ 1.5" slip with a 1.25" FTP w/ 1.25" slip. The 1.25" male with 1.5" slip gave me a prety big surface area that will come in contact with the o-ring and glass. I got o-rings from Ace Hardware that had an inner diameter that matched the outer diameter of the Male thread and the outer diameter of the o-ring matched the external diameter of the 1.5" slip part giving me an o-ring width of .25".

It did not screw down all the way so i used a scrap peice of 3/8" acrylic with a hole drilled into it to add width; I hand tightened it as much as possible and is now water tight with an external overflow box of only 1.75" off the tank that can handle approx 900gph according the the calculator!!!
 

ddenham

Premium Member
I have used a 1" MPT adapter and a 1" FPT adapter for years like this. The rubber gasket on the bottom of carbon and micron filters for RO units can be forced onto the male adapter fot the inside gasket. I had to use another gasket on the outside of the tank as a spacer, however, because the fittings would tighten before compressing the gasket. I happened to have sch 80 fittings on hand, and prefer to use those because they have a larger bearing surface on the inside gasket.
 

bkwudzjeep

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<a href=showthread.php?s=&postid=8116295#post8116295 target=_blank>Originally posted</a> by Kaos
bkwudzjeep: Thanks allot, you've eased my mind some. How long did you have the system running like that? I'm just curious to see if I will have any trouble over the long term.

It was around 1.5 years....the only reason I stopped using it was because I sold the tank and overflow box.
 
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