Re: Austin A30 Seven
Posted: Sat Sep 17, 2016 7:29 pm
So, a bit of a struggle due to my damaged arm, but it has been improving every day lately so I decided to tackle the petrol tank last weekend. It has already been off during previous work so I should probably have paid it better attention then but a quick inspection fooled me into believing it was ok.
I decided to start by removing the sender unit and siphoning out most of the fuel, this left an inch or so at the bottom of the tank and given the Irn Bru like colour of the stuff that came out I figured I'd remove the drain plug and remove the rest.
Now, I knew already that these tanks are prone to tearing out the female part of the drain that was soldered in at the factory, what I hadn't realised was some past villain had already managed to do just that and glued the whole thing back in place with fibreglass resin or similar, so, as soon as I gently tried to turn the drain plug the assembly simply fell out. Just as well I tried anyway, as this sort of repair would likely have bit at the most inconvenient time in the future.
This meant not only did I have to try and clean the tank innards I also had to repair a tank that for the last sixty years has been sucking petrol into every seam and rust pore, not the best situation when heat is going to be needed for the repair.
Anyway, the following was at my risk, not recommended, but my choice, so that is my disclaimer for those who might be tempted to do similar
Petrol tank drained fully,
Not much in the way of large debris but a lot very fine rusty silt.
With the tank off I first cleaned it out a bit with some gravel and water, then flushed it several times with soapy water.
That done I sat it with the air compressor feeding air through it to help purge as much of the fumes / fuel residue as possible, I left it like this for a couple of hours.
So, even then I'm left with a potential bomb when I come to repair it, and I actually wanted to weld the female part of the bung into the tank rather than solder it so I can remove the drain plug without worry in the future, so, a potentially risky procedure.
There were several options then, one being to take the tank down the garden, rig a fuse and set it alight, after the recent injury to my arm I wasn't feeling that brave, another possible is to displace the fumes with exhaust fumes or Inert welding gas, I'm not keen on that because I can't actually see if the gas / exhaust fumes are still in the tank after filling or leaking away.
To be honest, there is no guaranteed safe way for a home repairer, but working on the fact that the less area inside the tank that can hold fumes and potentially explode the better I opted for simply blanking the sender hole, sealing the tank filler and filling it with water. No void should really mean no fumes and no explosion.
One root run, two welds to the sides of that, and one bloody big weave weld over the top meant a big weld but saw it nicely sealed at the first attempt, and no one is going to tear it out again in a hurry.
Dried it out for another couple of hours with compressed air, put it back on the car and sighed with relief that my fingers / eyes and other extremities were all still intact.
Three gallon of nice fresh unleaded and she's bumbling about quite nicely with no signs of anything nasty at the filter.
Right, I know I've been a big girl keep going on about the risk, but I was confident enough with my method, I've spent a large part of my working life round flame, welders and explosive risks so was happy enough if a little wary, but, I haven't wanted to understate the risk, which was still present if reduced substantially by doing it the way I did simply because I don't want anyone to just take a heat source to something like this without serious consideration first.
Teaching granny to suck eggs regarding danger in most cases I know, and others probably wouldn't condone even what I did, but its done dusted, back on and good to go
I decided to start by removing the sender unit and siphoning out most of the fuel, this left an inch or so at the bottom of the tank and given the Irn Bru like colour of the stuff that came out I figured I'd remove the drain plug and remove the rest.
Now, I knew already that these tanks are prone to tearing out the female part of the drain that was soldered in at the factory, what I hadn't realised was some past villain had already managed to do just that and glued the whole thing back in place with fibreglass resin or similar, so, as soon as I gently tried to turn the drain plug the assembly simply fell out. Just as well I tried anyway, as this sort of repair would likely have bit at the most inconvenient time in the future.
This meant not only did I have to try and clean the tank innards I also had to repair a tank that for the last sixty years has been sucking petrol into every seam and rust pore, not the best situation when heat is going to be needed for the repair.
Anyway, the following was at my risk, not recommended, but my choice, so that is my disclaimer for those who might be tempted to do similar
Petrol tank drained fully,
Not much in the way of large debris but a lot very fine rusty silt.
With the tank off I first cleaned it out a bit with some gravel and water, then flushed it several times with soapy water.
That done I sat it with the air compressor feeding air through it to help purge as much of the fumes / fuel residue as possible, I left it like this for a couple of hours.
So, even then I'm left with a potential bomb when I come to repair it, and I actually wanted to weld the female part of the bung into the tank rather than solder it so I can remove the drain plug without worry in the future, so, a potentially risky procedure.
There were several options then, one being to take the tank down the garden, rig a fuse and set it alight, after the recent injury to my arm I wasn't feeling that brave, another possible is to displace the fumes with exhaust fumes or Inert welding gas, I'm not keen on that because I can't actually see if the gas / exhaust fumes are still in the tank after filling or leaking away.
To be honest, there is no guaranteed safe way for a home repairer, but working on the fact that the less area inside the tank that can hold fumes and potentially explode the better I opted for simply blanking the sender hole, sealing the tank filler and filling it with water. No void should really mean no fumes and no explosion.
One root run, two welds to the sides of that, and one bloody big weave weld over the top meant a big weld but saw it nicely sealed at the first attempt, and no one is going to tear it out again in a hurry.
Dried it out for another couple of hours with compressed air, put it back on the car and sighed with relief that my fingers / eyes and other extremities were all still intact.
Three gallon of nice fresh unleaded and she's bumbling about quite nicely with no signs of anything nasty at the filter.
Right, I know I've been a big girl keep going on about the risk, but I was confident enough with my method, I've spent a large part of my working life round flame, welders and explosive risks so was happy enough if a little wary, but, I haven't wanted to understate the risk, which was still present if reduced substantially by doing it the way I did simply because I don't want anyone to just take a heat source to something like this without serious consideration first.
Teaching granny to suck eggs regarding danger in most cases I know, and others probably wouldn't condone even what I did, but its done dusted, back on and good to go