Need to fit a union onto the top of the fuel tank for fuel return on my MegaSquirt install.

My plan is to remove the sender unit and drill a hole about an inch away to enable me to fit a nut on the union.

Will drilling cause a BOOM ?

Tank does have some fuel inside !!

Yes...... It's a possiblity.. Could you not put the hole in the sender you remove? This should avoid the problem?

Dan

[Edited on 15/5/06 by Bluemoon]

What's your tank made of?

If it's aluminium then it won't spark - but the fumes may get ignited by a spark from an electric drill. You could try a hand drill.

You certainly should drain the fuel, as you will have to get swarf out anyway.

David

I dont like possibilities !

Tank is aluminium and i would be using a hand drill (not mains/battery powered).

I would also place a cloth under where i was drilling to catch anything falling in.

if you have to do it, drill by hand, slowly!

How are you going to get the swarf out?

Draining's not enough, fumes hang around for ever. Maybe drain and fill to brim with water ? (remember to drain out water afterwards )

Believe it or nor you get a bigger boom from a half empty tank than a full one.
If you fill with water it will be ok to drill, grind, weld.

Bu$$er, i was affraid i'd have to take the tank out

quote:

---

Originally posted by Bryan Sears
Believe it or nor you get a bigger boom from a half empty tank than a full one.
If you fill with water it will be ok to drill, grind, weld.

---

Do you want me to tell you how to save your life?

I guess your answer is yes!

First wash the tank out with hot soapy water (fairy liquid etc).
Then run a car engine and place the open tank onto the car exhaust for about 20 minutes.
Then at the end of a length of rod, light some newspaper and hold it against the tank opening. No ca-boom and it will be safe to cut/weld etc.

[Edited on 15/5/2006 by nitram38]

yeah but he doesn't want to take the tank out.....

filling up with water would do it but then how do you drain the water out afterwards?

what about cusing C02 from a MIG to purge oxygen fomr the tank - then seal it.

Drill it with CO2 connected ... but needs to be done in a well ventialated area preferable on a very windy day.

dodgey stuff really.

I wonder if filling it with another combustible liquid that is harder to ignite e.g. diesel or paraffin - then won't matter about draining it all as it will mix with the petrol and be burnt off?

I think Robin hood so sender that has a flow and return in the sender... Might be worth a look if it's a driect replacement?

Cheers

Dan

You cant make an omellete without breaking eggs.

A fuel tank is about 3-4 hours job

It's a fuel tank - so do it properly - half assed efforts and lazyness are what cause bigger problems down the line.

Just follow some of the good advice given on here and do the job properly.

The sense of achievement when doing something properly is great and not to mention reduces the risk to your own life in trying to bodge it together.

Good luck

It will take a lot longer to bury you than take the tank out, so do the right thing.

if there's anything to bury.

take the tank out ffs!

tom

IMHO most of this post is BS.
There should be no problen at all drilling a hole in an ally tank that has had fuel in it. Especially with a hand drill.
Drain the tank and drill it.
You will never draw a spark from ally except from static. so earth it and just drill the bugger.
If your close to the sender hole you should be able to catch any swarf that falls inside the tank. (which will be minimal). Your strainer/filter will catch any that does get in.

And by the way as long as you are in open free air the chances of a battery drill OUTSIDE THE TANK causing an explosion in this circumstance are probably about the same as winning the lottery.

except don't forget that someone wins the lottery most weeks - just never me

quote:

---

Originally posted by BKLOCO
IMHO most of this post is BS.
There should be no problen at all drilling a hole in an ally tank that has had fuel in it. Especially with a hand drill.
Drain the tank and drill it.
You will never draw a spark from ally except from static. so earth it and just drill the bugger.
If your close to the sender hole you should be able to catch any swarf that falls inside the tank. (which will be minimal). Your strainer/filter will catch any that does get in.

And by the way as long as you are in open free air the chances of a battery drill OUTSIDE THE TANK causing an explosion in this circumstance are probably about the same as winning the lottery.

---

Come on guys, dont want an argument

I personnaly cant see that drilling a 6mm hole into the tank with a hand drill through aluminium would cause a spark to ignite petrol vapours. ? ?

No arguements, just good advice.

Dont take risks if you dont have to!

Im sure what BKLOCO says is true, but theres no point taking risks. What if you dropped a spanner near it and it causes a spark. What if you forget something walk about come back and cause a static spark. What if.... What if... What if...

If you want to be blazay (SP?) rember it only takes a spark of 0.25 milliJoules to ignite petrol vapour. This isnt very much and can be easily exceeded.

Rember its sparks that are the problem with petrol vapour not heat (within reason).

so drill the hole naked - skin doesn't create static

just make sure its a warm day or the police man is very understanding

Can you fit the return line to the tank filler neck somewhere? , if you have a seperate cap and neck connected with hose then just remove that and fit the return to it.
Paul.

If you are a professional then you should know the health and safety at work act?
PPE is the last resort.
In otherwords, during a risk accessment, your first question is, "Can this job be done in the ABSENCE of explosive vapour", not "Oh good, here I am going to do this the most dangerous way I can and prove how clever I am".
You may have spark proof tools, but your average novice does not.
The advice to use a battery drill in an earlier post is downright stupid.
I think you will find that you cannot take any form or electric drill into a petrolchemical plant.
As a professional electrician, I would not give out advice to a novice to work on equipment with vapour present, anymore than I would to advise a beginner to work on live mains.
If you want to do it, then fine, but do not advise others to try, who have no experiece or training to do this safely.

As to the faraday comment, I have seen a small spark, hit a 1/2" hole in a 2 foot square gas meter.
It became a 6 foot jagged piece of metal very quickly, plus it went 40 feet into the air! ( the meter was dis-connected but had a small amount of gas left in the centre of the meter in the regulator)

[Edited on 16/5/2006 by nitram38]

[Edited on 16/5/2006 by nitram38]

[Edited on 16/5/2006 by nitram38]

[Edited on 16/5/2006 by nitram38]

I'm very sorry but you are totally missing the point here.

You CANNOT draw a spark between steel and alluminium/Steel and brass/steel and bronze etc etc. The material is simply too soft

I am waiting to hear your explanation of how this "spark" is going to be produced by any means other than electrically.

We also need to get this debate into some perspective here!!!!

We are NOT talking about petrochemical plant. Where all electical equiplent must be certified as intrinsically safe.

We are talking about an alluminium fuel tank that has been used.

If you are that worried about risk I would suggest that you should NOT be planning to drive a kit car.
The risk of having an accident in it is FAR greater than the risk involved in drilling a hole in an alluminium petrol tank!

It would once again seem that this debate is not getting anywhere so this will be my last post on the subject. I hope we can just ammicably agree to disagree.

I never said that the hand drill method would cause a spark, but what if something else did?

No vapour=no explosion.
Pretty simple really.

As to the car comments, you know nothing about me or my driving or my car building skills, so this point is irrelevent to the discussion on whether the tank is safe to drill or not.
The fact that the question has been asked, shows that this person is unsure.
If you have any doubts, then use the safest method possible is all I am suggesting.
An extra couple of hours on a 3 year build will not make a difference, but 3 years recovering from burns might.

Blimey, come on lads, calm down.

I have taken notes of everyones reply and i thank everyone for there concern.

The only other place i can drill is on the filler neck, pushing a damp cloth into the neck below where im drilling.

I'm glad I didn't read this thread before I drilled my tank.

I took out the sender unit, then realised I couldn't put the return connector there, so the next best place was at the top of the tank above it. I stood the tank up outside (empty of course) and put some card in the hole the sender unit fits in (to catch the swarf) and slowly drilled (with my cordless drill) a hole in the top. I then changed the bit to a cone drill and enlarged the hole. The card caught all the swarf. I fitted the return pipe connector. Job done in half an hour.

Looks like I took my life in my hands as I was wearing nylon Y fronts at the time!

yeah - if the fashion police had seen you, ye gods, you'd be in prison now with a burly bloke calling you mavis!

LOL

Do you think my idea will work then...push a damp cloth into the filler neck below where im drilling ?

I thought about the filler neck at first, but then soon realised the connector I got had to be on a flat surface. During the engine conversion there's been two places where I've had to drill a round 'pipe' and fit a connector. One was in the exhaust for the lambda, and the other was in a water hose connector for the water sensor. Both times I had some problems getting a decent seal.

I wouldn't put the return pipe in a round filler neck for that reason, especially as the pipe in question is pressurised.

Think you'll have to make up your own mind on how your going to do this.

As guy above says its quite difficult to get a good seal from unions to a curved surface. If theres a flat on the tube it would be a better position.

You definatley not got space at the edge of the sender / float plate to put in a union?

I sometimes wonder how I've ever survived this long without the internet to stop me doing stupid stuff. If I was using a hand drill I would have put a blob of grease on to catch the swarf and drilled through without even asking.

bear in mind some of us are a lot more techincal than others. I'm sure my dad would intrinsically know the answers to half the questions on here yet he can't work a PC. I can work a PC without thinking about it and intrinsically know the answers to a lot of problems, yet when it comes to cars i haven't got that natural background.

My opinion...

Fill the tank with water...

and drill 2 holes!!

one on the botto of the tank, where you wled a nut! you then have created a drain plug!!

you also drill the above one and put on that return pipe!!


anyway what i would do is just empty the thing..

and let it as open as you can during one week outside...

(day and night) the fapour will then be gone...

the last action you could do is

heating it up slowly sow the vapour action is going faster sow the fuel empties of fapour...

or use compressed air to make the fapour air mixture more lean....

also i ALWAYS would test the tank before drilling it with some open fire.

if it explosed then you know you did the right thing...if it doesn't you are sure that while drilling / welding it wont happen to!!

if it has some fapour in it (after all those action, it cant be much and you will hear a woush... and at least you are prepared for a woush...

and when one woush has been there there won't be another one...

i also opinion that if you can make the job safer by taking the tank out then i just would do it!!

Its simple if there is any thing you can do to make the risk smaller wy you wouldn't do it???

wy do the job and risk that you son is coming taking a look and that he smokes or comes showing his new zippo???

think i would just fill it with water,

make the hole, drain it out as you can, test it with fire, weld it if needed....

and when you have everything sorted you will like it even more!!

water is a good thing because fuel stays on top of it sow you help it getting out to the last drup... also when near the entrance you could easyly try to ignit it in fact it would explode anymore just burn.....


also have to say that Fuel/Vapour/Drilling/TANK

isn't an easy theme to talk about safely...

Tks

also make sure you disconnect any hoses/ fuel pumps..etc..

because if there comes woush you won't want the flame in the pump or fuel line...

etc. etc.

Tks

Ok guys.........im going in.........

Its took 15 mins to remove the tank and 2 mins to drain about a pint of fuel.

Time to drill, if i dont reply to this post soon - call the fire brigade

grrr....

Done it !


Attached a picture..........













































Washing the tank out now with water.