Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 21-01-2015, 19:04   #31
Registered User
Privilege's Avatar

Join Date: Oct 2009
Location: Bermuda
Boat: Privilege 435
Posts: 218
Images: 12
Re: Drilling into diesel tank while full?

What sort of fuel filter do you have before your engine? Many of them have a 2nd outlet which will prevent a syphoning problem and clean your heater fuel too!

Privilege is offline   Reply With Quote
Old 21-01-2015, 21:04   #32
Registered User
Boatyarddog's Avatar

Join Date: Nov 2014
Location: Olympia, wa.
Boat: Mariner Ketch 32- 1979- hull 202
Posts: 621
Re: Drilling into diesel tank while full?

Install a dip tube at the top, thru the inspection port.

Sent from my iPad SV Cloud Duster

Boatyarddog is offline   Reply With Quote
Old 21-01-2015, 21:57   #33
Senior Cruiser
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 9,127
Send a message via Skype™ to Jim Cate
Re: Drilling into diesel tank while full?

This is not professional quality advice, but FWIW, our Fab All diesel heater has been running T'd into the main supply line for the engine for ~18 years and over 100K cruising miles. It even works when tapping the rather deep keel tank, with a lift of ~ six feet. We use a small electric pump and 1/4 inch lines throughout. No problems noted with air leaks or inability to lift from the tanks.


Jim and Ann
s/v Insatiable back in MBTBC marina, waiting for next eye jobs to be done
Jim Cate is online now   Reply With Quote
Old 22-01-2015, 10:32   #34
Nearly an old salt
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Drilling into diesel tank while full?

Originally Posted by W3GAC View Post
I've installed several diesel heaters. DO NOT TAP INTO THE MAIN ENGINE FUEL LINE. Three reasons: 1) Air sucks easier than diesel... any breach/ leak in the heater fuel line/ filter line in the future will shut down your engine/ require that you find the air leak, fix it, and bleed the engine fuel line/ system before you'll be able to restart the main. Do you really want to add this unnecessary risk during a storm/ harbor entrance? 2) The typical small piston fuel pumps for diesel heaters are not very strong and can't lift a typical 3/8" fuel line column of diesel very far. Most diesel heater fuel lines are very very small (about the size of a plastic ballpoint pin refill) for that reason and warnings about not tapping/ using regular fuel line are all over the instructions/ warnings. 3). Anytime the main engine is running (especially if your engine has a return line to the tank) it creates a suction on the supple fuel line tap. The weaker heater fuel pump will not only have to overcome the weight of the larger column of the main line but also the negative suction pressure of the main fuel pump pulling fuel up from the tank.

Sent from my iPhone using Cruisers Sailing Forum

This may or may not be true. But while ebespacher would prefer to use the standpipe , they do support the fuel line tap. On my boat #4 I did just that, the engine being a 55hp 4 cylinder nanni, both engine and heater never missed a beat

The eberspacher is primarily a truck cabin heater , where they are regularly tapped into the fuel feed.


Sent from my iPad using Tapatalk
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! -
goboatingnow is offline   Reply With Quote
Old 22-01-2015, 11:17   #35
Registered User

Join Date: May 2010
Location: Elsewhere on the Water
Posts: 569
Re: Drilling into diesel tank while full?

Originally Posted by rwidman View Post
What are you going to do about the diesel fuel pouring out once you start drilling until you finish and get the fitting installed?
OK, this is a bit off topic, but some may find it of interest.

I have known mechanics who apply a shop vacuum to the vent port of a diesel fuel tank while changing a valve at the bottom of a tank with a great deal of fuel in the tank. Two things I find amazing are: Air enters the opening at the bottom of the tank with no fuel leaking out with the valve removed, and the air with diesel fumes does not ignite when passing through the vacuum.

And I would add: Don't try this at home! Maybe they used an ignition proof shop vacuum, and know the vacuum power required for the depth of fuel and size of the valve.
St. Elsewhere is offline   Reply With Quote
Old 23-01-2015, 19:56   #36
Registered User

Join Date: Dec 2014
Posts: 375
Re: Drilling into diesel tank while full?

Originally Posted by minaret View Post
Very foolish. We fill tanks with an inert gas (usually Argon) before cutting or welding, even after cleaning. Safety first.

Argon - Wikipedia, the free encyclopedia
Good advice, one thing to remember is an empty or near empty tank is more dangerous than a full tank. I would have no problem though machining on any tank that had diesel in it. Machining and welding are two different things. I don't think either are the solution for this issue.

captlloyd is online now   Reply With Quote


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Teeing diesel.stove overflow into engine overflow to main tank svtatoosh Engines and Propulsion Systems 6 06-12-2013 15:46
How full do I fill my diesel tank? agilmore Engines and Propulsion Systems 60 09-12-2012 12:06
Full Ahead to Full Astern . . . Very Quickly deltasig Engines and Propulsion Systems 14 13-09-2010 21:40
Drilling into Gelcoat Successfully gbanker Construction, Maintenance & Refit 11 10-01-2010 05:23
Lashing Points without Drilling into Core ? thinwater Construction, Maintenance & Refit 5 07-11-2009 15:04

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 15:53.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.