Holding Tank: how to get a 4" hole threaded - FPT - SailNet Community
 
LinkBack Thread Tools
post #1 of Old 07-12-2007 Thread Starter
Senior Member
 
Join Date: Jun 2006
Posts: 398
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 9
 
Holding Tank: how to get a 4" hole threaded - FPT

I am ordering a high density polyethylene (HDPE) holding tank made.

I want to put a 4" hole at the top so I can use it as a clean-out port. Something I can put a stick in and poke around. I will use one of those standard pvc plugs as a hatch (same thing that is in your sewer line clean out that the roto rooter guy uses).

The maker can thread all the holes except that one. He doesn't have the tap and can't afford it for only one job.

Any ideas on who might be able to do this type of thing?

I sent out a few emails to plumbers, but without success so far.

thanks,
gh
groundhog is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of Old 07-12-2007
Senior Member
 
Freesail99's Avatar
 
Join Date: Feb 2006
Location: New Jersey
Posts: 4,507
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
 
Send a message via Yahoo to Freesail99
Many winery tanks, have an 8 inch handhold. Which is a 8 inch lid that screws into place. Maybe add wine tank to your search to pull up a few more companys.

S/V Scheherazade
-----------------------
I had a dream, I was sailing, I was happy, I was even smiling. Then I looked down and saw that I was on a multi-hull and woke up suddenly in a cold sweat.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Freesail99 is offline  
Quote Quick Reply Share with Facebook
post #3 of Old 07-12-2007
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 14 Times in 12 Posts
Rep Power: 14
         
Umm.. why don't you find a deck inspection plate that you think will do the job, and have the tank maker leave a hole the size required by the deck inspection plate. Then you can attach the deck inspection plate deck ring to the tank and use the deck plate as the inspection hatch. I am using a clear Beckson 6" circular screw-in deck plate for the inspection hatch on my holding tank. The reason I went with a clear deck plate is so I can do a visual inspection as necessary, and only open the inspection hatch if absolutely necessary.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #4 of Old 07-12-2007
moderate?
 
camaraderie's Avatar
 
Join Date: May 2002
Location: East Coast
Posts: 13,877
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 16
     
Mayb something like this instead?
West Marine: Locking Deck Plates Product Display
camaraderie is offline  
Quote Quick Reply Share with Facebook
post #5 of Old 07-12-2007
Telstar 28
 
sailingdog's Avatar
 
Join Date: Mar 2006
Location: New England
Posts: 43,290
Thanks: 0
Thanked 14 Times in 12 Posts
Rep Power: 14
         
I used this instead... I think it seals better than the locking type ones do.

Sailingdog

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
sailingdog is offline  
Quote Quick Reply Share with Facebook
post #6 of Old 07-12-2007
Owner, Green Bay Packers
 
Join Date: Sep 2006
Location: SW Michigan
Posts: 10,318
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 12
       
Go to your plumbing supply house and get a 4" bolt up flange made of PVC. It'll gasket inside and out, and the plug screws in. Cheap.

“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.
sailaway21 is offline  
Quote Quick Reply Share with Facebook
post #7 of Old 07-12-2007
Member
 
6string's Avatar
 
Join Date: Oct 2006
Location: Delafield WI
Posts: 96
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Quote:
Originally Posted by sailaway21
Go to your plumbing supply house and get a 4" bolt up flange made of PVC. It'll gasket inside and out, and the plug screws in. Cheap.
This seems like a good way to go. However, should for some reason you still need to machine the threads, there is a way to have that done without using a tap. You would have to take the part to a machine shop where they can thread mill on a CNC machine. I make a living helping people with threading many different materials. Should you want to pursue this route and would like more info, PM me and I will help you out.

Jeff
6string is offline  
Quote Quick Reply Share with Facebook
post #8 of Old 07-13-2007
Senior Member
 
Join Date: Dec 2002
Posts: 118
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 13
 
Have a cover plate made of same material 3/4 inch larger than the opening. Then tap the tank with 10-24 screws and using a fuel resistant gasket of the same size ( neoprene )put it all together with washers and lock washers/ screws. Works great
chuck711 is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Holding tank location stoutwench Gear & Maintenance 17 04-11-2007 02:40 PM
Custom Holding Tank Mithril Gear & Maintenance 6 03-15-2007 03:48 PM
Holding Tank Questions John_colpitts Gear & Maintenance 14 08-31-2006 06:42 PM
holding or fuel tank Jeanneau Beneteau Myblueheaven Cruising & Liveaboard Forum 0 02-28-2005 09:34 AM
Holding Tanks Tom Wood Gear and Maintenance Articles 0 06-10-1999 08:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome