Fuel Tank sub frame repair

Just purchased a 05 XB12R Firebolt, seems bike was dropped on side and punctured tank at one time, this was fixed but my fabricator friend wants to repair totally as there is small leak still . My problem is how do I get the tank sealant out with out damaging aluminum? I’ve asked around a lot and nobody seems to know! Were these Sub frames just replaced back in the day when damaged? Everyone I’ve found no matter price is damaged ( was going to buy one then fix it up for later swap) I’m up in BC Canada and parts seem rarer up here :upset: . Any help or advice on this would be great. I’m just looking ahead before I tear whole bike down for this, this coming winter.

Your post brings up more questions to me. Where is the leak how does he want to fix it? If it was from a tip over and the frame was even dented then it would be a total loss or a complete frame replacement. There are frames out there and even some bikes needing engines.
Post some pictures so we can see what’s going on.

If it was damaged significantly enough to leak gas, I wouldn't mess around and cheap out. I'd replace it. But then you have to deal with the VIN# is stamped on it as well:( The paperworks not fun but a fairly straight forward swap.

I've seen inside plenty of Buell frames and I'm not aware of any sealant inside a OE tank. Perhaps from a previous half-ass failed attempt? If it's meant to be submerged in gasoline and survive, I can't think of any way to remove it within reason.

To me the "subframe" is the part that is bolted on to the frame as a unit that holds the seat and battery tray.

Yea it looks bad..I picked away bondo from a previous fix it looks like. I’ll get pics up shortly, I was hoping for a remove the tank and aluminum weld to fix. But was told there is a liner inside because raw fuel would eat at the aluminum. I got bike relatively cheap and with only 8k on it. This is my only problem so I’m trying to come up with a solution. Sorry I call any half frame under a normal tank a subframe, this one just happens to be tank inside a frame…

The complete "foundation" of your XB consists of the main frame-subframe-swingarm.
And YES...the Italian manufacturer installed a sealant coating on the inside of all XB frames.

Intersting, I'm pulling another fuel pump soon. I guess I'll take a closer look. Aluminum doesn't react with gasoline, so if there is any coating inside, maybe it's a precaution for corrosion? Like in a boat? Plenty of raw aluminum tanks out there for racing and such and I've seen plenty of corrosion inside Buells:upset:

Still can't think of anyway to remove a coating. If you re determined to repair it, why not purge it and heli-arc the repair from the outside?

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Not sure if pic attached, but I found a solution after spending a hour at local Harley shop talking to couple of Buell racers..yes the tank is lined, yes I can weld it, no I cann’t take out inner liner, after I get work done on tank I’ll powder coat it which will burn out rest of liner in tank…yes it’s there for protecting the aluminum from corrosive gas…was told to just make sure tank is empty in off season and not have gas sitting in it for months on end. My quick fix for rest of summer will be to grind off all bondo and take out that plug (it’s not JB weld) I’ll JB weld every that looks like a leak, and enjoy bike till fall. Thanks everyone for the help! I’m sure I’ll have more questions down the road! Cheers!

After you weld it, you could just use gas tank epoxy and reline it. Good Luck

I once worked in an aircraft paint shop, that also involved coating removal in different forms. For tanks such as fuels and oils we had the option to submerge strip the tank in chemical baths. Paragon was the name of the worst I delt with, Diphase Carbon Removing Compound and Paint Stripper.......hideous stuff!! Extremely eco toxic, if splashed on your bare skin it would result in instant purple swollen chemical burns that left horrible scars, peeled skin and if it didn't make you instantly sterile, your off spring was guaranteed to look something like the orange 3 eyed fish from the Simpsons.
It cleaned up any tank linings...... especially good for motorcycle tanks before repairs!! REALLY REALLY good at removing carbon deposits from cylinder heads with out having to media blast or wire brush. I can't count the amount of engine blocks and NON aircraft parts I cleaned up for other work mates.