The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Richard A on 02.06. 2017 19:04
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Bike, just about to go back on the road after rebuild and find petrol now leaks from tank seam. Most frustrating.
Question is do I get the seams re-welded, or do I go for one of those seal repair kits. The weld will likely cause problems with the paintwork
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As far as I'm concerned, tank liners/sealants are junk.
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My own experience is that sealants work with isolated pin holes but will not cure split seams or cracks or holes or perforations.
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I had the (freshly painted) plunger tank leaking at the bottom seam. A mate, who is a professional welder, silver soldered it. It only required a (very) minor paint touch-up to have it as new again.
To be on the safe side, I sealed the inside but I have a feeling that wasn't really necessary.
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Check carefully which kit you choose. On other fora there are tales of freshly lined tanks failing, the lining coming off or turning to sludge. I had a leaky seam on my Velo tank which I repaired successfully with solder after the previous owner's attempt to line it failed.
Incidentally, I too have a leaky Star Twin tank - can't find the precise point it is leaking - but my bike is currently sporting a Gold Flash tank suitably painted. I like the 4 1/4 gallon capacity.
(See same reply on BSA Owners forum).
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I have just restored a suzuki x7 ( sorry guys) ,the fuel tank leaked in many places ,tried to tig weld it but it was just too thin ,like a couple of other post have said ,i found that silver solder was the only real repair option .
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I think this has come up before in other threads, my tank leaked from the front top and I used a small blow torch and soft solder to fix it, it's ok years later. The method is to get as thick as possible layer of solder stuck on over the leak, which means heating the tank and solder only just enough so the solder does not get too molten.
I did the same on the seam at the bottom of the oil tank, tho I had to redo that after a couple of years.
The damage to paint was minimal but could not be avoided....
There is a 2 pack epoxy glass fibre type product that might work....if it's out of sight. See:
http://www.selleys.co.nz/trade/specialist-products/epoxy-adhesives-fillers/knead-it-multi-purpose/
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I've used 'Liquid Steel' on a couple of leaks- one on the bottom of my Hilux tank, and the Beeza tank where the tap 'boss' cracked, and also some kinda hairline crack on my Gutzzi tank, which I almost forgot about.
I think it's also a Selley Product
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I have used Caswell Plating (two part epoxy) very successfully over the last 15 years. The Super Rocket has held up that entire time, even with ethanol laced fuel in it at all times!
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Step one needs to be identifying the failure mode. Is it rusted inside? Was it running without the strap tying the two halves together on the bottom side? (don't know that to call it). Until the root cause is addressed, I think you'll likely see it fail again in the future.
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+1 for the Caswell. I've had good/fair results with POR15 but just did a carbon fiber "Duck" tank and it looks the goods.
Cheers
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I use "Red-Kote" Fuel Tank Liner, works OK for me but the tank must be clean and dry, it took over a week to dry out so as no moisture could be seen seeping up from the seams.
Peter
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Tank 'liners' as they call them seem to work for some, but not for others. But when a chemical sealer fails you're left with an almost impossible problem of stripping it out.
-Silver solder, and bigger holes can be patched with copper sheet silver soldered on.
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Soldering (preferably soft) is my preferred option, but I did another bike with POR 15 and I have to say it's really good.
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Same here, POR15 was the first liner I had success with and still holding fuel
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Same here, POR15 was the first liner I had success with and still holding fuel
I used it to seal rust in my tank. All good so far.
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Another "+1" for Caswells. I just went to the garage to poke at it to be sure I wasn't kidding myself. Still solid after about 10 years with fuel in the tank. After loose flakes of rust are shaken out the Caswells encapsulates all remaining rust residue making it irrelevant. I don't believe you should ruin your paint job trying to get it welded or soldered (which may or may not work) versus using Caswell's. Still, just an opinion, but I seem to be in good company.
Richad L.
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I just looked up the Caswell product because I've been holding off lining my tank because of indecision (I'm sure it will leak when I finally get around to it because the chroming left it very thin on the sides after getting rid of the dents and external rust, and the bottom just looks "fragile"!) Based on the feedback here and my review of the product on line, it would seem that it works very well immediately and over time, and is relatively easily applied.....any additional thoughts before I purchase would be appreciated, thanks *help*
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Just follow the instructions to the letter!
I'll be using it in the Cafe's fiberglass tank soon.
Let's put a container of fuel over a heat generating plant. Then put it between our legs *eek*. Now shake the container *sarcastic*
Cheers
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Oooh but just don't live long enough that you have to strip the shite out!!! (because it WILL need it one day!)
(Leave that to your kids). *razz*
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I think I have mentioned this before.
I watched a guy at a bike show soldering old two piece harley tanks.
He had a old wood stump with MAP gas torches stuck in it.
He would start heating the bottom seam of the tank, then he would pour some type of flux into there and get that moving around and hot.
Then a big handful of solder pellets and he would keep heating and swirling the tank through the torch flames. It was like a circus act watching this guy do this, really entertaining.
You did not know if he was going to launch the tank and dent it all up, or start his pony tail on fire first. *ex*
When he was done the entire bottom of the inside seam was soldered up beautifully and he still had hair!
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now THAT would be sight to see, sounds like a great outcome though, I wonder how long it took to perfect the process!
Its a bit like watching the old guy beat the dents out of the tank, how they manage to get right into the front where the fork tubes punch into it and beat out the dents to a metal finish.....amazing craftsmanship *yeah* *yeah*
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Oooh but just don't live long enough that you have to strip the shite out!!! (because it WILL need it one day!)
(Leave that to your kids). *razz*
Jools,
I would think that after 10 years, if it was going to happen, the Caswell's would be showing some signs of breaking down. As far as I can tell, it is not. Now, can a tank with Caswell's on the inside be chromed on the outside? Don't know. Caswell's is a two-part, epoxy-type, material, stripping it out would probably mean splitting the tank and blasting because no solvent is likely to affect it, but I'm not a chemical engineer. Maybe some acid would work. I believe it will be quite some time before you cannot get a bashed-in tank to restore if you are bent on splitting one open.
OK, I'm done trying to defend my decision to use Caswell's. So, I will keep fingers and toes crossed that I am right. *smile*
Richard L.
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I can report that having a tank powder coated is an amusing way of removing a liner. I did this unknowingly on a T3 I had, and I guess the heat in the powder coat process was too much for the liner (whatever it was). I ended up with what looked like a whole bunch of loose uncooked prawn crackers in there. Unfortunately the filler had an ‘anti-surge’ tube in it so I had to rig up some garden hose to a vacuum cleaner and then suck the crackers out one at a time.
I guess if you are going with a liner it would need to be at least 10% ethanol proof. Here in the UK the max is currently 5%, but I dare say that will change … for the worse. Allegedly a lot of high octane c. 97 is ethanol free and I use that for preference in all my bikes. But I’ve heard horror stories of tankers just being topped off with ethanol before leaving the refinery, and with a bad mix you could end up with 30% ethanol, but can that be true?
I was talking to an air brush artiste at an HD meet up just last week and I was asking what lacquer they use on tanks to proof them, and she said they pretty much acknowledge that nothing is ethanol proof, you mostly have to limit exposure; from leakages and seepages I suppose.
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Hmmm, I think the Caswell product seems to have the best rep and its local, if I got 10 yrs plus, that cant be a bad thing! Yep it becomes my kids issue then too *evil* *evil*, so while I don't actually know whether it leaks or not, there is no question in my mind that after the bashing it has had (getting bent and then repaired ie x2 at least!), then the liner becomes good insurance I think....thanks all.
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Please may I ask, being not familiar with the sealing products.....
In the petrol cock area, do I presume blanking the threads with a BSP plug is required before pouring and swilling around? Is it possible in this area there is a possibility that it is not 100% sealed and petrol/ethanol/water can track between metal and sealant? Likewise around the filler cap area. Does the Caswell product include a rust treatment chemical, or, just "smothers" the existing rust preventing further rusting?
All the best....
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Here is the link to the Caswell's product including instructions. http://www.caswellplating.com/epoxy-gas-tank-sealer.html
Petcock holes get filled with "putty or Play-Doh". The filler neck gets covered with plastic wrap held on by a rubber band. I found it interesting that there are specific instructions for removing failed Kreem or Por-15.
Richad L.
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When I did my tank I put polythene over the petrol tap bosses held in place with elastic bands. This meant the threads got filled with sealer so I bought a suitable thread tap and cleared the threads.
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Many thanks Richard and Greybeard for your informative replies.....
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No, sorry; memory playing tricks! I did use a couple of BSP plugs that I bought but I still needed to clear some of the thread with a thread tap.
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BSARGS650,
PM sent
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My personal opinion, for whats its worth, is always going to be solder, silver solder or weld.
I dont trust the sealers and altho I have not tried the one you are talking about I have tried a few others and never had much joy at all.
Yes it ruins your paint but at least its done and dusted
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The only tank sealer I have never heard one good thing about is "kreem".
From what I've heard is it doesn't work at all,
Then you get to try to get that crap back out.
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Ha, I found a way to remove Kreem. Methanol eats it! I used it to seal my alloy oil tank on the racer. The methanol blow by the rings mixed with the oil and started on the tank. A big flap of Kreem covered the outlet and starved the motor. As the oil pressure dropped I stopped the motor. Couldn't find anything wrong and started with full pressure. A few minutes (half a lap) later no oil pressure. Found it by chance. Jammed a spring in the outlet fitting to hold off the Kreem and kept racing.
When I got home I filled the tank with 99.9% racing methanol. 2 days the Kreem was gone.
Cheers
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Heeheeheeeheeee!
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I cleaned out my tank with Evaporust which was useless only removed a small amount of rust . I then cleaned with water and a final swirl with petrol and oil . The bottom of the tank looks ok but when I put a finger inside around the filler hole a brown sludge is there which is likely flash rust and keeps coming back .
The POR 15 website instructions say only do as a last resort ! I wonder does using these chemicals have a long term effect on the metal .