To date, the most successful method of creating synthetic mechanosensitive polymers that undergo liquid-to-solid transition is by inserting weak bonds, "mechanophores," within polymer chains that are converted to an active intermediate in response to force, capable of strengthening the material . This work , in contrast, uses the shielding group concept, starting with uncrosslinked, shielded polymers that can undergo a rapid liquid-to-solid transition upon application of force. To accomplish this, graft polymers bearing reactive epoxide groups are mixed with small molecule amine/thiol crosslinkers. Ultrasonic irradiation is used to apply high strain rates to the shielded polymers. Straining of the graft polymers overcomes their steric barrier to interaction with the small molecule crosslinkers, facilitating a reaction, that rapidly strengthens the material. The resultant materials achieve elastic modulus values comparable to ultra hard commercial epoxy coatings. We anticipate that these shielded polymers will be useful as extremely hard and solvent-resistant coatings and as adhesives that can be cured by focusing ultrasound through the surfaces the adhesive is bound to.