How can these be removed without shattering the tank?
You are watching: How to remove rusted toilet tank bolts
I would try a Dremel type tool with an abrasive cutoff wheel. Of course you need to be careful of the porcelain. I"ve cut many screws and bolts this way.
If you can"t cut the bolt, you may be able to cut the nut, in the direction of the bolt"s axis, then pry the nut apart at the cut line.
A great tool for this purpose and any similar close work is a ultrasonic multitool such as a Fein, Rockwell etc. Lots of tool companies are making them now. the other tool would be a hacksaw blade holder. It is not a full framed hacksaw, rather a handle that holds the blade and can get into tight places. Remember, save yourself a lot of frustration and use a good quality sharp blade, not a dime store, discount blade.
See more: This File Does Not Belong To Any Project Target, Unable To Run Code On Clion On My Mac
I recommend an old-fashioned mechanic"s nutcracker. Search the net for "mechanics" nutcracker tool", AKA "Mechanics" Nut Splitter". Many tool vendors make these. These will split a seized nut across the flats, by hand tightening a screw that drives a hardened wedge gizmo. Works in places not accessible to other tools, like saws or grinders. It will destroy the nut, but sometimes releases the bolt without inflicting additional damage on the seized threads.
Then, if possible, replace with new nuts and bolts of solid brass or stainless steel. The additional cost is trivial. However, it is not easy to find solid brass or stainless steel bolts, to fit toilets. It"s a mystery to me, why toilet manufacturers continue to install and sell replacement hardware made of steel that is only brass PLATED, which will eventually rust up, leak, and seize. Possibly, to create work for plumbers. More likely, to sell more new toilets, when perfectly good but leaky toilets get broken in efforts to remove corroded bolts with hammer blows, hacksaws, electric vibrating saws, or electric grinding wheels. Doze strategies are just too risky!