Bob Smith Industries Insta-Cure+ Gap Filling CA Glue, 2 oz Review (2026)

A gap-filling formula for imperfect fits

Insta-Cure+ is Bob Smith Industries' higher-viscosity cyanoacrylate, sold here in a 2 oz (56.8g) bottle, and it is positioned specifically for loose-fitting joints where the adhesive needs to bridge a gap rather than bond two flush surfaces. Metal and resin miniature parts, which do not always mate as cleanly as injection-molded plastic sprues, are a common use case for this thicker formula, since a thin, watery CA can run straight through a loose seam instead of filling it. BSI recommends laying down a serpentine bead with about an inch of separation on one surface before assembling parts, letting clamping pressure spread the glue through the joint.

Working time and cure speed

BSI's documentation for this glue calls for holding parts together for 5 to 15 seconds to reach an initial set, with full bonding strength reached after about three hours. That is a brief but real window compared with instant-grab thin CA glues, giving a painter just enough time to nudge a part into final position before the bond locks in place. For anyone converting or repositioning parts on a miniature, that small amount of working time can be the difference between a clean assembly and a part glued slightly off angle with no chance to correct it.

Bonding range and durability

Beyond miniature assembly, BSI lists this formula as effective on balsa and other soft woods as well as hard wood, glass, metal, fiberglass, ceramics, hard plastics, and rubber, reflecting its general-purpose hobby glue background from the radio-control and modeling world. Once cured, BSI states the bond remains stable across a wide temperature range, from -40 to 220 degrees Fahrenheit, which is well beyond anything a miniature would normally encounter but speaks to the adhesive's overall durability. The formula also pairs with BSI's Insta-Set accelerator for painters who want to speed up the cure time further on a given joint.

Handling a thicker CA glue

Because this is a gap-filling formula rather than a thin capillary glue, applying too much can leave a slight bulge or bead of cured glue at the seam if a joint does not actually need that much material to bridge, so painters working with tighter-fitting parts may prefer BSI's thinner Insta-Cure Super Thin formula instead. The bottle tip is also prone to clogging between uses, as with most CA glues, and BSI's own instructions note the value of clean nozzle care and refrigeration to extend shelf life. A pin or fine wire kept nearby for clearing the tip is a practical habit for anyone using this glue regularly. Wiping the nozzle after each use and storing the bottle upright helps keep it flowing smoothly between sessions.

Bottom line

This 2 oz Insta-Cure+ is built for the specific job of bridging gaps on loose-fitting metal or resin miniature joints, where a thinner CA would simply run through without holding, and its brief working window gives just enough time to align parts before the bond sets. It is not the ideal choice for tight, flush plastic joints where a thin capillary glue works cleaner, and careless application can leave visible glue bulges that need cleanup. For painters regularly assembling metal or resin kits with imperfect part fit, it is a practical, economical size to keep on the bench.

Frequently asked questions