The Hull Truth - Boating and Fishing Forum

Go Back   The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > The Boating Forum
Search

Notices

Random Quote: Keep the water under you, not over you!!
Reply
 
Thread Tools Search this Thread
Old 07-22-2012, 11:59 PM
  #1    
Admirals Club
 
Join Date: Sep 2009
Posts: 317
Default Drilling a Hole In Gas Tank

Have aluminum gas tanks and want to drill an 1" hole in the top of the tanks.

I need to install new gas gauge sending units. My existing units are really difficult to access and someone has messed up a few of the mounting screws. After a few hours of trying to remove them, I decided new holes would be easier.

Since the tanks are aluminum, it has been suggested that a hand operated drill and a good 1' hole saw should do the job.

Any suggestions or other ideas would be appreciated.
__________________
Donzi Sweet 16
Pursuit 2870
St John, USVI
maitman99 is offline   Reply With Quote
Old 07-23-2012, 01:36 AM
  #2    
Senior Member
 
Join Date: Nov 2009
Location: Australia
Posts: 888
Default

I have cut holes in my plate alloy boats side decks for rod holders using a standard old hole saw and it works fine.

To put it mildly, though, you'd want to have that tank completely free of gas fumes before you put a drill, let alone a hole saw, anywhere near it. Sparks will fly. And so will you if theres any fumes still in there when that hole saw cuts thru to the inside. It will also throw heaps of alloy shavings inside that you will want to flush out somehow.

Cheers

ML
Moonlighter475 is offline   Reply With Quote
 
Old 07-23-2012, 04:49 AM
  #3    
Senior Member
 
Join Date: May 2011
Posts: 706
Default

aluminium is pretty soft - you can generally work it with hand operated woodwork tools - so a hand drill will be fine.

as for fumes and sparks - i dont reckon they mix real well. and while cutting the hole should be straightforward i have zero knowledge of the safety aspects involved.
puppy is offline   Reply With Quote
Old 07-23-2012, 04:55 AM
  #4    
wik
Junior Member
 
Join Date: Nov 2011
Location: Australia
Posts: 9
Default

I have read previous that you are supposed to fill it with water to reduce the chance of ignition. I'd research it further as im no expert on the subject
wik is offline   Reply With Quote
Old 07-23-2012, 04:57 AM
  #5    
Admirals Club
 
Join Date: Jun 2009
Location: Amongst the FL fishies
Posts: 3,378
Default

Assuming you can get into the tank, use a knock-out hole punch, not a hole saw. Fewer shavings and smaller sized drill.

http://www.zorotools.com/g/Knockout%...FQTqnAod-ywAuw

http://www.grainger.com/Grainger/GRE...738?Pid=search
airbrush is offline   Reply With Quote
Old 07-23-2012, 04:59 AM
  #6    
Senior Member
 
Join Date: Apr 2006
Posts: 2,268
Default

Drain the tank, let it breath for as long as possible (weeks preferably), then fill it with water, an inert gas, or connect it up to your running car exhaust for a long period. Playing with gas tanks is always real scary, but aluminium should not spark against your steel tools. It is more likely that you will get a spark from within the tool itself. Whatever you do be very careful and make sure that the tank is full of something other than gas (petrol) fumes.
Aliboy is offline   Reply With Quote
Old 07-23-2012, 05:02 AM
  #7    
Senior Member
 
Join Date: Aug 2008
Posts: 124
Default

I too am getting ready to add sending units to both my aluminum tanks.

I have been told that aluminum will not spark. I would hate to prove that theory wrong. I believe most power tools emit or are capable of internal sparks which could be a problem. So hand drilling sounds like the way to go.

Either way, I am going to completely remove any trace of gas or fumes.

Like described above, the shavings should also be taken into consideration.

I am curious to hear the replies.

Thanks,
VC
vcinri is offline   Reply With Quote
Old 07-23-2012, 05:34 AM
  #8    
Admirals Club
 
Join Date: May 2009
Location: St Petersburg, FL
Posts: 2,731
Default

A 1" dia. hole will not allow the average float to be placed in the tank. We use 1 1/2" hole saws, air tools or cordless when working on gas, if it were diesel the risk is rediced greatly.
Work on the tank in a will ventilated area out side where there is plenty of air movement.
__________________
Absolute,

Suckin Sludge & Havin a Gas
Absolute is offline   Reply With Quote
Old 07-23-2012, 06:08 AM
  #9    
Senior Member
 
Join Date: Dec 2010
Posts: 2,251
Default

air tools is the ticket no sparks from the drill.

Before cutting the hole which mine are 11/2" make sure you don't hit a baffle . you need to be able to see inside the tank to know where the baffles . to close to one and the unit will hit the baffle on top on one and you have to patch the hole some how .
docters oarders is offline   Reply With Quote
Old 07-23-2012, 06:15 AM
  #10    
BannedCaptains Club Member
 
Join Date: Aug 2002
Location: MA and ME
Posts: 16,795
Default

If you can get aluminum to spark you're a genius. DO NOT FILL THAT TANK with water. Use argon welding gas or a mix of it and C02.
Mist-Rest is offline   Reply With Quote
Old 07-23-2012, 06:24 AM
  #11    
Admirals Club
 
Join Date: Jan 2011
Posts: 132
Default

Sounds stupid but I had a cracked tank about 7yrs ago took it to Padeia's Raditor shop in San Benito Tx.
He filled it with water then poured a cap full of gas on top of the fill tube and started draining the tank gas burned till it was just about empty. he welded it and I never had a problem with it again....

Disclaimer :::DON"T DO THIS I don't recommend this...
__________________
Island Time --- man---100 T Capt. 25yrs. The older I get,,,The Better I use to be.
ITman is offline   Reply With Quote
Old 07-23-2012, 10:12 PM
  #12    
Senior Member
 
Join Date: Nov 2009
Location: Australia
Posts: 888
Default

I also had an alloy tank that had a leaking filler fitting some years ago. Drained the tank of all gas, took it out of the boat, then the welder hooked it up to the exhaust of his car, we ran it for 10 minutes, then flushed it with water.

Welded fine after that. We didnt blow up ourselves or the tank. Yes, he used air drills for drilling holes too.

I know the theory about ally not sparking when drilled or cut. Maybe though, it might be a job for the Mythbusters to test first before one of us tests that theory the hard way....!

Final task was to drill a small hole in the corner to drain all the water and flush the alloy filings out, then welded the hole up.

Ater leak testing the tank, it was refitted and a pint of metho was added, then a full tank of gas. The metho absorbs any remaining water droplets, same as ethanol does. Ran that tank thru the motor and never had any problems.

Cheers

ML
Moonlighter475 is offline   Reply With Quote
Old 07-23-2012, 10:29 PM
  #13    
Admirals Club
 
Join Date: Oct 2010
Location: Sarasota
Posts: 2,313
Default

Where are the drilling shavings going? OMG, never drill a tank that has or had gas in it. Send a video.
__________________



Stamas Americana with F300 Yamahas

Tow trucks are GMC Duramax's

Boat trailer is an Owens Slide-On.

Thank you God, for making me someone who loves to fish.


Build thread: http://www.thehulltruth.com/boating-...-new-boat.html
76 Stamas is offline   Reply With Quote
Old 07-23-2012, 11:00 PM
  #14    
Member
 
Join Date: Apr 2004
Location: Saint Simons Island, GA
Posts: 31
Default

Back in the 1950's I was involved in flat track (dirt track)motorcycle racing. I saw a lot of guys do welding repair on bike gas tanks by simply pouring a little carbon tetrachloride, which is non-flammable, in the tank first. The carbon tet fumes are heavier than air, which displaces oxygen in the tank and won't let any gas fumes left in the tank explode. Now dealing with the aluminum shavings from drilling is another matter, but they should be trapped in a good fuel filter system.
reel dawg is offline   Reply With Quote
Old 07-24-2012, 07:29 AM
  #15    
Admirals Club
 
Join Date: Aug 2008
Location:
Posts: 1,167
Default

You really, really, really can kill yourself by drilling any tank that has had gas in it. True, working the AL will not make sparks, but the brushes in your drill motor sure will (they are NOT ignition protected). Once your hole is open, fumes will leave the tank, mix with the air, where they could easily be ignited by the drill motor and -BOOM- you are as dead as last nights chicken.


Forget about ventilating the tank. It would be impossible to ensure the fume concentration is low enough. I have heard of the dry ice thing, but I think displacing the gas space with water and ventilating the bilge is probably the safest method.

Metal shavings/spirals could collect at the pickup and in bends in the piping. Once lodged there, over time it could mix with other debris and cause a blockage. I think they have to be removed.
__________________
Edgewater 318-F300's
Tampa Bay
scooperfl is offline   Reply With Quote
Old 07-24-2012, 07:38 AM
  #16    
Senior Member
 
Join Date: Mar 2011
Location: Algonac michigan
Posts: 3,017
Default

Quote:
Originally Posted by reel dawg View Post
Back in the 1950's I was involved in flat track (dirt track)motorcycle racing. I saw a lot of guys do welding repair on bike gas tanks by simply pouring a little carbon tetrachloride, which is non-flammable, in the tank first. The carbon tet fumes are heavier than air, which displaces oxygen in the tank and won't let any gas fumes left in the tank explode. Now dealing with the aluminum shavings from drilling is another matter, but they should be trapped in a good fuel filter system.
Well carbon tet has been banned for 20 years as a cancer causing substance and exposing it to high temps released phosgene gas.So many people have been killed torching the tops off 55 gallon drums and working on gas tanks that it is simply not advisable to do it. Use the original hole and clock the sending unit a few degrees and use new screws into new holes after you seal the unit to the tank with seal all and a new gasket.
muskamoot is offline   Reply With Quote
Old 07-24-2012, 08:56 AM
  #17    
Senior Member
 
Join Date: Jan 2011
Location: Loxahatchee, Fl
Posts: 427
Default

My suggestion is to find someone you dont really care for and bet him $100 he can't do it. right after you call your insurance company to verify your coverage is active.
King Killer is offline   Reply With Quote
Old 07-24-2012, 09:19 AM
  #18    
Senior Member
 
Join Date: Sep 2008
Location: Lafayette, La.
Posts: 3,692
Default

IF you're going to try it, a long extension for the drill will keep the drill motor away from the fumes. A BIG fan and a shop vac (big one) running to keep the shavings from falling into the tank will help, but who knows how it will work. There's got to be some sort of snipper or nibbler that can do it. Be sure to video it so we can watch.
Mike
__________________
Earth without art is just,...........eh.
beenie is offline   Reply With Quote
Old 07-24-2012, 10:49 AM
  #19    
Senior Member
 
Join Date: Mar 2011
Location: Algonac michigan
Posts: 3,017
Default

Quote:
Originally Posted by beenie View Post
IF you're going to try it, a long extension for the drill will keep the drill motor away from the fumes. A BIG fan and a shop vac (big one) running to keep the shavings from falling into the tank will help, but who knows how it will work. There's got to be some sort of snipper or nibbler that can do it. Be sure to video it so we can watch.
Mike
The video of the jet engine effect when the shop vac sucks gas fumes into it...Priceless.
muskamoot is offline   Reply With Quote
Old 07-24-2012, 12:23 PM
  #20    
Senior Member
 
Join Date: Jun 2012
Location: Wahoo Bay,Fl
Posts: 103
Default

I would pop out the existing screws to the sending unit off,use an easy out to get the broken ones out and re tap new holes and ur done!
farside2 is offline   Reply With Quote
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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

 



©2009 TheHullTruth.com

Powered by vBulletin® Version 3.7.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.2.0