Semlos Heat Blocking Putty Jar 12 oz — Moldable Heat Insulation Clay for Valves, Sight Glasses & Welding

Overview

Semlos Heat Blocking Putty Jar is a compact 12 oz moldable insulation clay designed to stand up to high heat and keep critical surfaces protected during soldering, brazing, and welding tasks. The formulation blends a natural, non-toxic hydrogel-ceramic composite containing silicon, aluminum, and sodium, delivering reliable performance without harmful additives. The texture feels clean and pliable, accommodating a wide range of shapes and joints, while remaining usable across multiple projects with proper care.

Key benefits

• Safe, non-toxic composition with no harmful additives.
• Excellent heat resistance to minimize heat transfer to surfaces and components.
• Malleable texture that adheres well and molds around valves, sight glasses, and fittings.
• Reusable for up to a year with proper care, reducing replacement waste.
• Drip-free, mess-free handling that cleans up quickly after use.

Why it matters for your projects

When soldering, brazing, or performing fusion welding, protecting sight glasses, TXV valves, and other heat-sensitive parts can influence joint quality and equipment performance. This putty acts as a portable heat barrier, letting you shape a custom shield around edges, threads, and connections in seconds. It can be removed without leaving residue, so you’re ready to tackle the next task with minimal downtime.

Common use scenarios

• Sight glass installations: shield delicate glass from radiant heat during sealant curing or welding.
• Valve protection: cover TXV valves and directional valves to limit thermal exposure.
• Line components: insulate liquid line filter driers, ball valves, and fixtures to preserve performance.
• Welding prep: create a temporary heat barrier around joints and outlets for added protection.
• General reuse: reshape and reuse across multiple projects over months to a year with care.

Tips for best results: store in a cool, dry place and away from direct flames. Re-soften the clay by kneading until it returns to a pliable texture before reuse.