Tank Repairs

[RichardL]

So, the dip is not standard, then, I take it. I had assumed not, but it’s so uniform The tank had a big dent at the lower front, so maybe that’s when the upward force was applied.

[muskrat]

G'day Richard.
As it's a tube I'd exert pressure from the bottom with heat around the top.
Cheers

[trevinoz]

That looks like someone has pressurised the tank trying to push the dent out.

[RichardL]

Well, Trev, you’re making me worry that I may have done it when pressurizing to find leaks while using leak detector fluid. Though, my clay plug for the filler hole tended to pop out pretty easy with much less pressure than I envision for bulging the tank.

Anyway, guys, if I heat the top while pushing from the back (a feat unto itself), should I push on the backside of the rubber landing, or on the recessed circumference around that landing? It would help to know how the tank is constructed so I don’t cause a separation. You are more than familiar, but I’ve attached a picture of the backside of the rubber landing, anyway. (There is an old repair there, too.)


Richard L.

[limeyrob]

Before doing anything I think Trev has raised an important point.  There are two ways this dent could have happened:

1 the tank was forced up while bolts down by the centre bolt and the tube has been pulled down.
2 someone pressurized the tank, perhaps to remove a dent, and the top has gone up.

The fix to both could be very similar but the shape you are aiming for, or get, could be different.  I would try to get it alongside a known good tank and try to work out exactly what the difference is.  In case 1 you want to push the tube up so that both the top and bottom of the tank change. In case 2 you want to press the top around the tube down without disturbing anything else.

How does it look from the front?  I've seen tanks that have been over pressurized try to open out a bit so the bottom of the sides are further apart.

[muskrat]

G'day Richard.
Does the underside look/feel like it's proud (pushed down)? If not Trevor's pressurization theory has merit.
Cheers

[trevinoz]

I think that to repair that you would have to completely dismantle the tank and beat/shrink it back into shape.
I have seen my friend do it but it is a hell of a lot of work.
You could also fill it with bog.

[limeyrob]

What does it owe you in $?
The more I look at the photo the more it looks like over pressure.  I wonder if you could pull a vacuum while heating that area?
What could possibly go wrong...

[berger]

fill it , become a lead burner

[RichardL]

I owe a bunch of replies for all good advice. Just a bit tired right not for a re-evaluation. Probably tomorrow.

Thanks,

Richard L.

[limeyrob]

I appreciate you are in the US, but I've posted a link to a tank on UK e-bay because there are a lot of photos and especially one of the top looking side on.
I think your best strategy is to look for another tank and come back to the dented one later.  They seem to be quite common and there must be a lot in the US.
https://www.ebay.co.uk/itm/166956003762?_skw=bsa+petrol+tank&itmmeta=01J7ZGEZED0YEM2RTC1GE9YR9N&hash=item26df5a71b2:g:9jcAAOSwvIZm2b5d&itmprp=enc%3AAQAJAAAA0HoV3kP08IDx%2BKZ9MfhVJKkHjMCdyXMpxmE%2BHTj8vyFXnP6ZVVAj0vz2dSS43OfWq%2BNcWq7Bkqi3bZXR7iWoy6ndIAOcUbWBTY2K9gWx%2FwncjmfmS7rddjfRDhigL%2B60Kvx49CTLMz%2BIBvy89XFyRekIxaoL0B%2FT%2FX%2FUf2rGOgzWQdd7GDWYYgmSGxP2l5vDbU8CtZlZn5jLwJzpeDV58z13QnXhHnDUw4ArPdo0xQUoYOkfS8etrJpNYjc0j%2FSMNS38c33Rq9cnr51HFBbuXG8%3D%7Ctkp%3ABk9SR6b3u_C_ZA&edge=0