- that's a very neat mod
- just as you said - a real tight fit, but very careful shaving did the job!
. I used Quicksilver fuel line, the same stuff that's used for the main fuel line betwixt t'tank and t'engine. I chose this as it was recommended in this thread, but also after I checked it was a homogeneous material; one solid 'plastic' throughout its wall. Obviously if the inside can cope with petrol flowing through it, so can the outside with being immersed!
( Mercury/Mariner Quicksilver Outboard Petrol Fuel Line 8mm ID 5/16" Sold by M | eBay
It was 8mm I/D and fitted nicely tight on the ~8.5mm fitting spigot (I warmed the pipe gently first). Ok, the threaded hole in the Barrus tank was ~15mm I/D, so with the considerable wall thickness of the pipe once fitted over the spigot it just wasn't going to go back through! It almost
did, and I managed to get half-way through by 'screwing' it all back in, so that the fuel pipe had a thread grooved in to it. But that only got me part way, even with using silicone grease!
So, very careful whittling with a sharp craft knife got the diameter down to a snug fit, and I then successfully managed to screw the fitting + pipe back in to the tank.
There was plenty of wall thickness left - the vast majority - so I have no concerns about weakness there. I only pared off a half mm or so all around.
Job done - tanks with a new lease of life!
(In case if it's of interest, I also refurbished the two Barrus caps as the air vent inserts had rusted and seized - one had completely broken away. I also found that one of the rubber seal rings on the cap was completely perished, and the other was missing. Guess what fixed all this? A fab adhesive product called 'StixAll' by Everbuild.
This is amazing stuff, which sets to a very tough rubbery compound. It'll stick almost anything to almost anything! It is also incredibly inert, and a test dollop had no reaction to being immersed in petrol even though the stuff was straight out of the tube and hadn't even set. Ok, I need a long-term test on it being petrol resistant, but so far so very good.
Ok, two repairs here: the first was the air vent screw. I removed the brass vent screw and the steel sleeve it sat in. Clamped in vice, and managed to unscrew them apart. Cleaned up both with taps and dies, and gave it a smear of copper-ease. All very free and easy to use. I then refitted the parts, the sleeve from the inside and the brass screw from outside, and did them up so the sleeve was held firmly in the correct place. (I had removed all the badly rusted bits of the sleeve which were inside the cap - fortunately the actual sleeve part was intact.)
I then simply injected (it comes in a large cartridge which you use with a 'skeleton gun') the StixAll all around the sleeve and completely filled that central recessed area of the cap. Smoothed it off, left it out in the sun for a couple of days (quite a depth of StixAll!) and the air-vent fixing is now fully air tight in the cap and also fully secure.
I then cleaned up the groove where the O ring used to sit, injected a bead of StixAll all around this, and then ran a little metal former I'd trimmed out of thin sheet all around the stuff. Did this a few times, removing excess StixAll each time, until I was left with a raised, flat-topped 'O' ring literally moulded in place. (The former I used was simply a thin piece of scrap metal sheet (less than half-mill thick) cut with shears to an easy-to-hold size (around 50mm x 10mm) with the required 'O' ring shape cut out from one corner. This was approx 6mm wide x 1mm high. When I ran that shape around the cap insides, it left that raised 6mm wide x 1mm high 'rubber' StixAll band. (The actual
formed 'band' is deeper than 1mm as there was also a ~3mm deep recess for it to sit in. So the whole formed StixAll band is approx 6mm wide and 4mm deep in total - and it's adhered
to the cap, so shouldn't go anywhere!)
Allowed to fully set (it's really tough stuff) and then a goodly smear of silicone grease (completely inert lubricant) all over everything to protect it further, and to make actual use that much smoother and easier.
The cap has never been easier to use, and the tank is completely air tight when it's on.
A lot of work? Not at all. What possessed me to even try? Simple - new replacement caps are nearly £40 each... )