A7 ST petrol tank leak - weld or tank sealer?

[Greybeard]

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.

[RichardL]

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.

[Jules]

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 

[muskrat]

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  . Now shake the container 
Cheers

[Joolstacho]

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).

[coater87]

 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.

 When he was done the entire bottom of the inside seam was soldered up beautifully and he still had hair!

[Jules]

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 

[RichardL]

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).

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. 

Richard L.

[Butch (cb)]

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.

[Jules]

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  , 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.

[BSARGS650]

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....

[RichardL]

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.

[Greybeard]

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.

[BSARGS650]

Many thanks Richard and Greybeard for your informative replies.....

[Greybeard]

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.