Moorron
|
| posted on 5/2/07 at 10:19 AM |
|
|
quick question help!
fitted my new alloy fuel tank and its got the smallest leak possible, will 2 pack glue (arldite cant spell it) be ok to use or isnt it petrol proof?
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
|
|
RazMan
|
| posted on 5/2/07 at 10:26 AM |
|
|
I am fairly sure that epoxy resins are petrol resistant but make sure you 'key' the surface just before application or oxide will degrade
the bond.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
02GF74
|
| posted on 5/2/07 at 10:30 AM |
|
|
did you not test it before fitting? fitting an air line then spraying the outer with soapy water?
How difficult would be to unfit and weld it up? I would have thought not too much as you have just fitted it.
you'll need to purge the petrol out before bring a spark/flame to it.
Where is the hole? - what are the consequences of the eopyx patch coming ?
You'll only need to weld it up once so tkae the time and get it right now.
|
|
|
BenB
|
| posted on 5/2/07 at 10:36 AM |
|
|
I would suggest quite strongly not to re-weld the pipe. From what you describe it sounds like there's petrol in that there tank!!! I don't
know of a single method of flushing the vapours from the tank that is totally satisfactory and I've personally treated too many very nice but
rather silly people who've welded stuff that's had flammable material inside....
From a quick google search it appears epoxy is petrol proof (ie okay for making the whole thing out of).
Abrading the ali surface is important- I personally think it has a lot to do with keying the surface (something for the ali to grip onto).... Really
should do a new experiment with ali sanded rough and ali sanded smooth (oxide layer off in both cases)... In my experiments with ali and epoxy I found
that when talking about an abraded surface, epoxy glues onto ali sheet like its untrue- I'd very much doubt the epoxy patch would ever come
off...
The only other important thing would be to clean the area well gluing.
|
|
|
Moorron
|
| posted on 5/2/07 at 10:56 AM |
|
|
The hole was right under the tank where i have build the baffle/swirl pot. It was dripping every 30 seconds so wasnt a huge leak. I would have brought
it into work to weld but its had petrol in it and im not sure if i will blow up with the fumes left in it.
i did pressure test it and thats really peeved my off as i was sure it was all fine. ARGH! ive apoxyed it over night after i keyed the surface up with
wire wool. I just know its going to be one of those things in the back of my head from now on.
the gaffa isnt in tomorrow so i might just scratch the glue off and weld it IF someone can suggest a way of purging the fumes from the tank.
Would a heater blowing thru the tank evapourate the fumes and make it clear????
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
shortie
|
| posted on 5/2/07 at 10:59 AM |
|
|
DO NOT weld it without knowing exactly what you are doing with regard to welding petrol tanks and purging fumes!!!!!
Heard too many stories of serious injury when dealing with petrol fumes!!!
PLEASE be careful.
Rich.
|
|
|
BenB
|
| posted on 5/2/07 at 11:15 AM |
|
|
There are various options for welding tanks that have contained petrol....
Usually the best thing is to not do it or get someone else to do it!!! [JOKE!]
I would do none of the following (though they are what people do)....
1) fill it with petrol- its the vapour that explodes?!?!?
2) fill it with water and flush it through, but how to do you know when its fully flushed and how are you going to dry it out afterwards. Also, any
process that relies on heat is going to struggle with a tank full of cold water. If you empty the tank, you run the risk of any petrol left inside
vapourising, so back to square 1... And how long do you flush it for? Only way of knowing is when it doesn't explode!!!!
3) blow it through with air (hot or otherwise)- good chance of introducing lots of (hot) air into a petrol rich environment to get the air : fuel
mixture just right before introducing the spark.....
4) fill it with sand (presumably gets rid of the air) but cleaning it afterwards is going to be a PITA and you'll have some air in there....
All sounds a very bad idea. Case in point- one chap I treated was welding a jerry can that had cracked. "purged" it beforehand. Weld,
weld, weld, weld... Unfortunately, at this point he blew a hole in the tank (which was now full of super heated petrol vapour). Now obviously it holes
where the welding is going on, which is normally right next to your arm, head, face etc etc etc.... One five foot long flame of burning / exploding
petrol all over Mr Welder.... It wasn't pretty.....
Don't do it!!!
|
|
|
BenB
|
| posted on 5/2/07 at 11:21 AM |
|
|
quote:
Originally posted by Moorron
Would a heater blowing thru the tank evapourate the fumes and make it clear????
No but you might just break the land speed record for fuel tanks by turning it into a pulse jet....
|
|
|
MikeR
|
| posted on 5/2/07 at 11:23 AM |
|
|
i've heard of people filling the tank with inert gas - a favourite being the exhaust of a car & keep it running.
personally i wouldn't do it, but i have heard of others not killing themself (strange how i've not heard of people killing themselves -
probably cause they're dead!!)
another thing to look at is the JB weld stuff. I know NS Dev patched a rally car tank once - it was the middle of the night, emergancy repair, no idea
how long it lasted.
|
|
|
Ivan
|
| posted on 5/2/07 at 11:37 AM |
|
|
A family member of mine killed himself cutting open an "empty" drum of petrol after it had stood open for some weeks and according to
witnesses one couldn't smell any fumes 
Rather get specialists to weld it - the cost will be a lot less than your possible medical treatment or funeral.
|
|
|
bbwales
|
| posted on 5/2/07 at 11:44 AM |
|
|
Hi,
Whilst in the Army our metalsmiths used to repair the petrol tanks and the process was to flush the tank with water for 24 hours, or use an air mover
again for 24 hours. In the field or on active duty where there was plentiful supply of running water or electricity for the air
mover......NOT....they would fill the tank to the brim and then carry out the repair. As they would do the repair the rest of us would take
steps.......very long ones and very fast ones. But saying this we never had an accident.
|
|
|
smart51
|
| posted on 5/2/07 at 11:45 AM |
|
|
The important thing with glue is contact area. A piece the size of a 1p is easily knocked off or loosened with vibration. A 10cm x 10cm area of GRP
is less likley to come off as is has 100 times the contact area. Not that I'm recommending a GRP patch. fixing it properly is always better
than a repair.
|
|
|
John Bonnett
|
| posted on 5/2/07 at 11:46 AM |
|
|
I used a firm in Northampton to fit a swirl pot and outlet to my aluminium tank when I converted the engine to fuel injection. They made a nice job
and at a reasonable cost. They were not at all worried that it had had petrol in it but that was their job and they were specialists.
I would leave it the experts.
John
|
|
|
PeterW
|
| posted on 5/2/07 at 12:09 PM |
|
|
quote:
Originally posted by MikeR
i've heard of people filling the tank with inert gas - a favourite being the exhaust of a car & keep it running.
personally i wouldn't do it, but i have heard of others not killing themself (strange how i've not heard of people killing themselves -
probably cause they're dead!!)
another thing to look at is the JB weld stuff. I know NS Dev patched a rally car tank once - it was the middle of the night, emergancy repair, no idea
how long it lasted.
Seen tanks purged with Nitrogen and CO2 before now. its a specialised job too, which is why its best left to the professionals.
Most of the chemical metal and epoxy products will stop leaks like this, but they need a perfectly clean area to work on, and no leaking petrol whilst
they go off.
Cheers
Peter
|
|
|
gazza285
|
| posted on 5/2/07 at 12:24 PM |
|
|
Welded loads of tanks up. First remove the petrol, then swill out thoroughly with soapy water. Then mix water and washing up liquid so you will get
loads of bubbles, put this in the tank and shake baby shake. When the tank is full of bubbles remove any bungs, lids or caps and weld away.
DO NOT PUT ON KNOB OR BOLLOCKS!
|
|
|
nitram38
|
| posted on 5/2/07 at 12:43 PM |
|
|
I have welded loads of tanks and what I tell you may save someones life.
Make sure that there are no hidden compartments as these may contain fuel vapour.
First wash the tank out with soapy water.
And this is the secret to making it safe...........run your car engine and put the open end of the tank on your exhaust pipe outlet. In otherwords let
the exhaust fumes fill the tank.
Run it for about half an hour.
Test the tank with some lit newspaper on a pole.
Never had one explode, something to do with carbon monoxide kills the petrol fumes.
|
|
|
NS Dev
|
| posted on 5/2/07 at 01:13 PM |
|
|
quote:
Originally posted by MikeR
i've heard of people filling the tank with inert gas - a favourite being the exhaust of a car & keep it running.
personally i wouldn't do it, but i have heard of others not killing themself (strange how i've not heard of people killing themselves -
probably cause they're dead!!)
another thing to look at is the JB weld stuff. I know NS Dev patched a rally car tank once - it was the middle of the night, emergancy repair, no idea
how long it lasted.
Yep, worked a treat and never leaked as long as I knew the car, certainly fine for 3 years after (the car was sold on then)
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
|
|
|
02GF74
|
| posted on 5/2/07 at 02:01 PM |
|
|
quote:
Originally posted by nitram38
Test the tank with some lit newspaper on a pole.
ah, that should be quite easy now with all the eastern europeans coming over ....
(read somewhere else that filling the tank with sand will render it safe.... but how do you get it all out afterwards?).)
|
|
|
RazMan
|
| posted on 5/2/07 at 02:19 PM |
|
|
quote:
Originally posted by 02GF74
(read somewhere else that filling the tank with sand will render it safe.... but how do you get it all out afterwards?).)
Thats ok - the explosion should clear out most of it
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
gazza285
|
| posted on 5/2/07 at 03:03 PM |
|
|
quote:
Originally posted by nitram38
something to do with carbon monoxide kills the petrol fumes.
There should be very little CO in the exhaust these days, that's one of the things cats do, and I doubt that the CO will kill the petrol fumes
as CO is a highly flammable gas as well, it burns with a nice blue flame, think of tuned engines running open pipes sort of blue flame. It's
more to do with the nitrogen and carbon dioxide in the exhaust gas displacing any oxygen. Quicker with bubbles.
DO NOT PUT ON KNOB OR BOLLOCKS!
|
|
|
iank
|
| posted on 5/2/07 at 03:22 PM |
|
|
If you bought it from a supplier send it back and get them to repair it/fix it. Most claim to pressure test them before they are shipped.
If you can't frosts sell fuel tank sealing products (made by POR-15) though it isn't cheap.
http://www.frost.co.uk/productList.asp?catID=25&frostCat=Tanks
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
britishtrident
|
| posted on 5/2/07 at 04:03 PM |
|
|
For small leaks shellac base compounds work well used to be a brand name "Petro Patch".
Green and Red Hermatite are also shellac based but I haven't tried thos for the purpose.
Otherwise try epoxy based filers such as Plastic Padding
If you really want to weld it hot wash it out then steam it out with a car exhaust --- it will need several washes at least 6 hours steaming.
Oh and you could always just rub a bar of wet soap on it --- tradditional roadside repair.
[Edited on 5/2/07 by britishtrident]
|
|
|
gazza285
|
| posted on 5/2/07 at 09:02 PM |
|
|
Rinse with water and washing up liquid, then fill with bubbles, advise from a professional tank repair man, takes ten minutes. If in fear I'll
give you me Fathers number and he'll fix it for you, professionally like. With professional costs.
I'm 35 and I've done them that way for 20 years, but he's 61 on next Saturday and he's done them since the times of British
build quality, and worked at David Brown's (ask your dad, if he's a farmer, or rich enough to own an Aston.) without trouble, but he did
learn to not leave a full can of WD40 next to the vice while arc welding nearby. Garaged warmed up nice though..........
DO NOT PUT ON KNOB OR BOLLOCKS!
|
|
|
