Guitar Prop-Jack tool Brace Repair Jack top Crack Repair Tools acoustic making instrument luthier tools (Short)

The Prop-Jack is a purpose-built spring-loaded brace jack engineered for luthiers who need to re-glue loose or cracked guitar braces and soundboards without removing the top. Turned from tough, low-friction POM, each jack expands from a compressed length to a fully extended position and locks under spring tension, exerting constant, even pressure while the adhesive cures. A cross-cut saddle on one end bites into the brace to prevent side-slip, while the opposite magnetic tip pairs with any steel caul or rare-earth magnet placed on the exterior, letting you locate hairline cracks and clamp them dead-center. Available in three overlapping lengths, the tapered body offers a positive grip for fine-tuning compression inside dreadnoughts, OM, parlor or classical bodies alike

• 【Dual-Tip Design】Cross-notched cradle grips the brace; rare-earth magnetic tip aligns perfectly with external magnets for crack repair
• 【Constant Spring Pressure】Internal spring keeps steady, uniform force during glue-up, eliminating the need for bulky external clamps
• 【Expandable Range】Short (68–78 mm), Medium (89–102 mm) and Long (102–128 mm) models cover every common acoustic body depth
• 【Precision-Machined POM Body】Low-friction, non-marring material resists glue squeeze-out and withstands years of shop use
• 【Ergonomic Tapered Shaft】Rounded, ribbed profile gives fingertip control when compressing the spring inside tight sound chambers