The Thing and Sandman would be duking it out on some mountainous area far far way from New York city to assure no meddling bastard heroes would interfere, then the FF would show up and mess it up.
The Thing still needs air to breath, Sand man controls all sand around him. Sandman can't be physically hurt, u blow him up with a punch or a bomb and he just recollects himself. Water is one of his major weaknesses. Spidey beat him with his brains. Thing may be just smart enough to think of a good idea. Thing has a big mouth. Sandman should win, but I'm sure the Thing would pull somethin outta his ass to win, cuz Thing is a class A hero with more experience, and sandman is a class B villian. Sandman actually became an avenger once.
Sandman once accidentally fused with Hydro man and they became mudman, lol. Spidey was actually trying to cancel the two out, cuz they are each other's weaknesses, but just made it worse. They later seperated and went their seperate ways.
Sandman
Height: 6 ft. 1 in.
Weight: 240 lbs. in human form, 450 lbs. at maximum density and normal mass
Powers: Sandman possesses the ability to transform his body into a malleable, sand-like substance that can be hardened, dispersed or shaped according to his will. Also, he is able to increase his size and mass to an unknown extent by incorporating nearby sand into his form.
Thing
Height: 6 ft.
Weight: 500 lbs.
Known Superhuman Powers: The Thing possesses superhuman strength, endurance, and durability. The mutagenic, specific-frequency cosmic ray bombardment caused his musculature, bone structure, internal organ composition, soft tissue structure, and skin to greatly increase in toughness and density. The Thing can exert himself at high levels for about an hour before the build-up of fatigue poisons in his blood impairs his strength. His reflexes have remained at their above average human levels despite his greater mass. The Thing's lungs are of greater volume and efficiency than a normal man's, enabling him to hold his breath underwater for up to nine minutes, The Thing's five senses can withstand greater amounts of sensory stimuli than he could when he was a normal human being, with no reduced sensitivity.
The Thing's body is able to withstand extremes of temperature from -75° to 800° Fahrenheit for up to an hour before exposure or heat prostration occurs. He can withstand the explosive effects of armor-piercing bazooka shells (15 pounds of high explosives) against his skin with no injury. He is still susceptible to colds, disease, and emotional stress.
Unlike in the case of the Hulk, the Thing has suffered no loss of intelligence or change in personality in his transformation into his monstrous form.
Abilities: The Thing is a brilliant pilot of aircraft. He has had a great deal of experience at hand-to-hand combat, and was a formidable opponent in physical combat even before becoming the Thing.
Sandman wins. He could just suffocate the Thing by filling his lungs with sand. Physical attacks are virtually useless against Sandman. Unless the Thing has some kind of anti-sand chemical, than Sandman takes it.