Bulkhead size

logen32

logen32

Member
Hey guys
I have a question regarding the hole size and bulkhead fitting size. Ive read that the hole should always be bigger (usually 1" 3/4 size for a 1" bulkhead).
I want a 1 inch fitting but the largest drill bit I can find is 1" 3/8.
Would this still work or do you need a larger sizes hole ?
Thanks
Mike
 
tangs rule

tangs rule

Active Member
My BH fittings have an outside diameter of 1.67" for the 1 inch fittings, and 1.38 for the 3/4" fittings, and your drill bit measures 1.375" so I think it's time to goto the store. The 1 inch BH needs about a 1 3/4 hole. Are you drilling glass or soft stuff like acrylic?
 
logen32

logen32

Member
I will be drilling glass. In that case, could i just go for 2 3/4th bulkhead.
It's for my filtration. I will be using two 25 gallons, one of them being a refrigium which will be draining to my sump.
 
2quills

2quills

Well-Known Member
If you look at some of the aquarium supply sites that offer bulkheads they will tell you what size hole you need. The heavy duty Sch 80 bulkheads need a slightly larger hole than the Sch 40 stuff. Glass-Holes sells bits for cheap for drilling. If you keep them cool when you're drilling you should be able to get about 2-4 holes per bit.
 
tangs rule

tangs rule

Active Member
Yup - if your cuttin glass - jsut measure the OD of your fitting and goto:
http://www.glass-holes.com/Glass-Hole-Cutters_c7.htm to get the right diamond edged holesaw. That's where I got mine cause I had to enlarge 1 hole from 1" to 1.5"
each saw they sell comes with a chart for drill speed, the larger the saw the SLOWER you can turn the saw - so be prepared to turn pretty slow.
 
logen32

logen32

Member
Thanks guys. I always get great help for this forum. Gonna place an order.
Now i would also be drilling my main tank (100 gallons) would it be better to go with the largest size possible ?
 
tangs rule

tangs rule

Active Member
Quote:
Originally Posted by logen32 http:///forum/thread/386150/bulkhead-size#post_3390132
Thanks guys. I always get great help for this forum. Gonna place an order.
Now i would also be drilling my main tank (100 gallons) would it be better to go with the largest size possible ?
What do you mean? you cannot go too big, or there won't be enough room for the flange gasket to seal good. You kinda need to know which BH sizes you will be using and buy a hole saw for each size. I would not use a 1" BH fitting in a hole that was not drilled to 1.75", cause the OD of the fitting is 1.68". Putting a 3/4" fitting in a hole drilled for a 1"BH would be too big, as the hole would be 1.750" but the fitting od is only 1.380. you'd be missing about 1/2 your gasket flange area. You really cannot do a 1 size fits all approach unless all your BH fittings are the same. Also when installing BH fittings, use no lube or sealant. Just install the fitting with a NEW gasket and tighten to hand tight. (the rubber gasket goes inside the tank, between the glass and BH flange - only the nut is on the outside)
 
logen32

logen32

Member
Just was asking about bulkhead size. Not a drilling question..... Whether it would be better to have a 2 inch bulkhead as opposed to a 1 inch bulkhead. My train of thought is bigger bulkhead more flow of water.
 
2quills

2quills

Well-Known Member
Bigger is pretty much always considered better in regards to drains. Not always necessary though. I drilled mine for two 1.5" bulkheads on my 120g which is way more than I need but that's ok. At least I know that if for some reason one of them ever got blocked up then the other one could handle all of the flow. A 1.5" drain would give you double the drain capacity of a 1". Or two 1" drains would be nice as well.
 
acrylic51

acrylic51

Active Member
A big question that should have been asked is the bulkhead going in the back panel of the tank? Is there going to be an overflow box surrounding the bulkhead? If there is an overflow box surrounding the bulkhead the overflow box will dictate what it will handle not necessarily the bulkhead itself.
 
logen32

logen32

Member
No overflow box. My tank has a stone like build in the tank. The back left corner has enough coverage (I will put a small mesh so small fish don't get sucked in), so no overflow box is needed.
It's a little hard to explain so I'll post a pic later on today to get a better idea.
 
tangs rule

tangs rule

Active Member
Quote:
Originally Posted by logen32 http:///forum/thread/386150/bulkhead-size#post_3390266
Just was asking about bulkhead size. Not a drilling question..... Whether it would be better to have a 2 inch bulkhead as opposed to a 1 inch bulkhead. My train of thought is bigger bulkhead more flow of water.
I just read this again, and had a warning of sorts - a 2 inch dia bulkhead fitting will support 2" diameter PVC pipe. Unless your gonna run a 500g+ tank and big pool pumps (like I do) I wouldn't think you'd need anything near this big. The largest BH fitting that I have in the 475 is 1each 1.50" - and that one is the suction for a 4300gph "pool" sized recirculation pump. All the other returns & suctions are either 3/4" or 1" dia. I run almost 2000 gph flow thru a 1" dia pvc line, so I just didn't want you to order somthing that might be too big for your design. 1.5" and 2" pvc is pretty big stuff.
 
acrylic51

acrylic51

Active Member
Honestly the only time I'd run2" would be my feed lines to my CL pumps. I wouldn't opt any bigger than 1 1/2" bulkhead for drain, but even that is overkill for this application.
 
J

john tyler

New Member
I have a 222 actual gallons reef ready tank, I beleive it is oceanic, I need to replace all 4 bulkheads, hole sizes are 1 3/8" & 1 5/8", I want to plumb two 1" drains & two 3/4" returns. problem is I can't find a 1" bulkhead that fits a 1 5/8" hole size
 
lmforbis

lmforbis

Well-Known Member
You might need to go with the bigger bulk head then go with a reducer to get the plumbing to the diameter you want. Have you checked BRS? They have all kinds of plumbing.
 
J

john tyler

New Member
Scared to risk cracking glass trying to increase hole size, have a 125 gallon in living room floor waiting on a $190 replacement glass because the drill hole cracked all the way across the glass, can you tell me more about how to find BRS? Thank You for responding
 
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