Old fuel?

[ReinkeFandS]

So I decided to completely restore the Homelite Super XL I recently bought and when taking the gas tank apart this brown coating is all over the inside of the tank. The thicker areas peal off but where it's thinner it is a pain to remove. I was thinking it is where mixed fuel was and the gas evaporated.Has anyone else seen this and what works well to remove it?

[petefrom bearswamp]

We used to call that varnish and it was common in tanks where the gas had long ago evaporated.
Probably lacquer thinner will remove it.

[Ox]

If that don't get it, a little sandblasting will.  Just don't linger too long in a single spot, it'll eat through the aluminum.  And don't hit the mating surfaces.  Just put some electrical tape over them or be very careful.

I seems I ran across some of that years ago and nothing I had would dissolve it so I just left it there and I don't remember anything bad ever happening.

Homelite Super XL is one of my favorite chainsaws.  I cut mass amounts of firewood and sugarwood with one years and years ago.  Never die, always start, not picky, heavy, awkward, slow, loud.  They're the army truck of the chainsaw world.  Love em.  Don't forget to give a squirt of oil with your thumb in big cuts.  It's fun to listen to the revs pick up when you do.  Have fun!

[ReinkeFandS]

Thanks guys, I'm going to scape as much out with a plastic scraper, see what some carb cleaner does and anything left that wont disolve will be left in there (I don't have a sand blaster).
Ox- it has the auto oiler, but I do remember that from some of my dad's oil pioneer saws

[Texas-Jim]

Soak it couple days in charcoal light fluid. then carb cleaner blow it right off.

[jwilly3879]

Denatured alcohol will dissolve the varnish.