Jump to content
Sign in to follow this  
CaptJackalope89

Drilled my hole to big

Recommended Posts

I am in the process of setting up a 180gal acrylic tank. I bought a sweet low profile overflow box from modular marine and they use two 2inch bulkheads to connect the exterior box. 

 

The internet told me to use a 3inch hole saw. I sized up the the saw to bulkhead and it looked to be good until after i put 2 holes in the back of my tank. If i position the bulkhead in the center of the hole, the gasket and nut just barely make contact with the edges of the hole. 

 

I plan on trying to use a bigger gasket, but are there any other suggestions to help make this a more reliable seal? 

 

I have since found out that the proper hole size is 2 7/8 inches...

Share this post


Link to post
Share on other sites

Buy a 2 1/2 inch bulkhead put a bushing for 2 1/2 down to a reducer to a 2"

 

 

Sent from my iPhone using Tapatalk

 

 

 

Im not sure if I can do that. The 2 inch bulkheads are built into the low profile overflow box and are not removable. 

 

Would filling in the gap with some kind of liquid sealant be a good option?

Share this post


Link to post
Share on other sites

Im not sure if I can do that. The 2 inch bulkheads are built into the low profile overflow box and are not removable. 

 

Would filling in the gap with some kind of liquid sealant be a good option?

 

That's why you need the 2" - 2.5" bushing mentioned, it will convert from the 2 1/2" hole to the 2" in the overflow box.   

 

Good luck!

Share this post


Link to post
Share on other sites

That's why you need the 2" - 2.5" bushing mentioned, it will convert from the 2 1/2" hole to the 2" in the overflow box.   

 

Good luck!

 

Ok, I think I know what you mean, so this bushing would essentially be the new bulkhead nut. 

 

Something like this?

 

 http://www.pvcfittingsonline.com/439-292-2-1-2-x-2-schedule-40-pvc-reducer-bushing-flush-style.html?gclid=CIPAo-yXn9ACFZSHaQodumkG9g

 

Sorry, If im a little confused :/

 

Thanks for your help!

Share this post


Link to post
Share on other sites

Glue a patch on the back of the tank and re drill to correct size. Charles AKA wannareef can't assist with this I'm sure

This will be my last resort. I already have the glue/solvent from a center brace repair... I would just need to order the acrylic

 

Thanks!

Share this post


Link to post
Share on other sites

Wait a minute. You drilled 3" holes and they were supposed to be 2-7/8"? I don't think an eighth of an inch is going be an issue. Can you post a picture or two?

Share this post


Link to post
Share on other sites

Ok, I think I know what you mean, so this bushing would essentially be the new bulkhead nut. 

 

Something like this?

 

 http://www.pvcfittingsonline.com/439-292-2-1-2-x-2-schedule-40-pvc-reducer-bushing-flush-style.html?gclid=CIPAo-yXn9ACFZSHaQodumkG9g

 

Sorry, If im a little confused :/

 

Thanks for your help!

They are saying use a larger bulkhead that will fit the size of hole you drilled. And you'll use a reducer/bushing to neck down to the correct size plumbing you need.

 

I believe :)

  • Like 1

Share this post


Link to post
Share on other sites

Wait a minute. You drilled 3" holes and they were supposed to be 2-7/8"? I don't think an eighth of an inch is going be an issue. Can you post a picture or two?

 

Ya, if the bulkhead is resting on one edge, the opposing edge does not make contact with the tank.

 

I can take pictures on tuesday when i get home from work.

Share this post


Link to post
Share on other sites

They are saying use a larger bulkhead that will fit the size of hole you drilled. And you'll use a reducer/bushing to neck down to the correct size plumbing you need.

 

I believe :)

 

Thats what I thought. However the 2inch bulkheads are built into the overflow box, so I am stuck using them. 

 

I did read somewhere else to try putting o-rings around the bulkhead neck to help keep it centered in the hole

Share this post


Link to post
Share on other sites

I am in the process of setting up a 180gal acrylic tank. I bought a sweet low profile overflow box from modular marine and they use two 2inch bulkheads to connect the exterior box.

 

The internet told me to use a 3inch hole saw. I sized up the the saw to bulkhead and it looked to be good until after i put 2 holes in the back of my tank. If i position the bulkhead in the center of the hole, the gasket and nut just barely make contact with the edges of the hole.

 

I plan on trying to use a bigger gasket, but are there any other suggestions to help make this a more reliable seal?

 

I have since found out that the proper hole size is 2 7/8 inches...

 

The proper whole size is 3" for a 2" bulkhead. Are you sure you have 2" bulkhead take a piece of 2"pvc and see if it slips in the bulkhead. My guess is you don't have a 2" bulkhead. Looked at several sites they all say 3" even live aquaria please send pictures

 

Here is a link also

 

http://www.marineandreef.com/Lifegard_Bulkhead_2_inch_FPT_X_Slip_R270560_p/rrl30541.htm

 

878d3f681d86604936819f454e315ac1.png

 

 

Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

I am nearly positive its a 2inch bulkhead. That is what they advertise on the website but I never did double check. This is also why I drilled a 3 inch hole. I emailed the company Thursday and am waiting to hear back. 

 

I think I may be alright if I cut a bigger gasket since the actual internal box and external box will be against the tank, not the bulkhead...

 

I will take pictures on tuesday when I get home from work and post an update.

 

here is a link to the box I bought. It is constructed great! I just wish it came with some instructions on hole size.

 

http://modularmarine.com/collections/overflow-boxes/products/2400-gph-low-profile-overflow-box-bulkhead-mounted-aquarium-surface-skimmer

Edited by CaptJackalope89

Share this post


Link to post
Share on other sites

The holes you drilled in your tank should be the same size as the two holes in the outside overflow box. If the holes you drilled are a little bigger than the bulkhead it's not a big deal as long as the gaskets are making a seal. The seal is not made between the "neck" of the bulkhead and inside of the hole you drilled. The seal is made on the flat surfaces of the tank, gaskets, and the overflow boxes. Hope this helps.

Share this post


Link to post
Share on other sites

I am nearly positive its a 2inch bulkhead. That is what they advertise on the website but I never did double check. This is also why I drilled a 3 inch hole. I emailed the company Thursday and am waiting to hear back.

 

I think I may be alright if I cut a bigger gasket since the actual internal box and external box will be against the tank, not the bulkhead...

 

I will take pictures on tuesday when I get home from work and post an update.

 

here is a link to the box I bought. It is constructed great! I just wish it came with some instructions on hole size.

 

http://modularmarine.com/collections/overflow-boxes/products/2400-gph-low-profile-overflow-box-bulkhead-mounted-aquarium-surface-skimmer

So reading the site you posted. You should have 5 bulkheads 2 2" and 3 1-1/2" bulkheads you might be using the 1-1/2" instead. Will be better with pics on Tuesday

 

 

Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

Here are some photos of my problem and how I fixed it. Thanks for the advice everybody! I had a two inch bulkhead and drilled a 3 inch hole. Even though several websites say to drill a 3inch hole, it is too big. I found out the perfect size is 2 7/8

 

Here is what it looks like

post-16011-0-26280000-1479371647_thumb.jpg

 

with the nut

post-16011-0-39419800-1479371883_thumb.jpg

 

I bought some rubber material on amazon to make larger gaskets and used the 3inch hole cutout to make a ring to help keep the bulkhead centered in the hole.

post-16011-0-92811500-1479371959_thumb.jpg

 

I drilled pilot holes and screwed the disc down before cutting it with the 2 7/8 hole saw

post-16011-0-81551900-1479372111_thumb.jpg

 

Here is my ring! I sanded all the edges and sides with 100 grit sandpaper to smooth it out

post-16011-0-07367000-1479372216_thumb.jpg

 

Perfect fit! and IF the bulkhead slid down to rest on the edge it would still have a seal.

post-16011-0-44086400-1479372328_thumb.jpg

 

This shows the left side with the added ring the right side without. you can see how there would be a chance for a potential leak if the bulkhead did not stay centered. 

post-16011-0-81785100-1479372747_thumb.jpg

 

after adding my oversized gaskets between the outside of the tank and the external box. It is all mounted and my shiny new overflow box is ready to go!

post-16011-0-42998600-1479372871_thumb.jpg

 

I filled to the tank after plumbing my bean animal style drains and it has been running for a couple hours now while i clean my 140lbs of new dry sand without any leaks.

 

Thank you to everybody who gave suggestions. And I learned to not trust the internet bulkhead hole size info! A different manufaturer who makes 2inch bulkheads might need a 3inch hole. But in my case 2 7/8 was the correct size. I guess its better to make the measurements yourself!

 

I also have a 2inch bulkhead im attaching to my sump for an external pump. I bought that one from brs and it will also take a 2 7/8 hole perfectly... 

Edited by CaptJackalope89
  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×