1 Gram Measuring Cup: Accurate Small Epoxy Batches for Rockets

By High Power Model Rocketry | Published: 2026-11-04

Category: 技巧與保養

Learn how a 1 gram measuring cup helps you mix small epoxy batches accurately for rocket builds, with a step-by-step process and common mistakes to avoid.

Quick answer

Use a 1 gram measuring cup to portion each component of your epoxy by weight, then mix thoroughly. This gives you repeatable small batches without guessing, which is critical for reliable rocket assemblies.

Why small batches need a different approach

When you mix epoxy for rocket builds, small batches leave little room for error. A few extra grams of hardener or resin can throw off the ratio and weaken the cure. A 1 gram measuring cup lets you measure each part by weight in consistent increments, so you can scale down a batch without losing accuracy.

Many builders reach for a gram scale epoxy ratio, but not every scale resolves single grams reliably. The 1 gram measuring cup from Public Missiles is designed for measuring black powder ejection charges, yet its 1 gram increments make it a practical tool for small epoxy portions too. It is compact enough for field or workshop use, so you can keep it with your build supplies.

When this method works best—and when it doesn't

This approach shines for batches under about 20 grams total, such as fillets on small fins, tacking centering rings, or attaching launch lugs. For larger structural bonds, a dedicated gram scale with finer resolution is usually more practical because you will be measuring bigger quantities.

Also note that the cup measures volume marked in grams for black powder, not weight for epoxy. You must confirm your epoxy's mix ratio by weight and use the cup only as a consistent scoop, not as a calibrated scale. If your epoxy specifies a volume ratio, weigh a test batch first to establish the correct fill levels.

Step-by-step: mixing small epoxy batches with a 1 gram cup

Check your epoxy's mix ratio by weight: Read the manufacturer's instructions to find the exact ratio (e.g., 1:1, 2:1, or 5:1 by weight). If only a volume ratio is given, weigh a small test batch on a gram scale to determine the correct cup levels for each part. Never assume the cup's gram markings equal grams of epoxy; confirm with a test batch.
Set up a clean, level workspace: Place a disposable cup on a level surface and keep the 1 gram measuring cup, mixing sticks, and epoxy containers within reach. Use a dedicated cup for each component to avoid cross-contamination. Label cups 'resin' and 'hardener' before you start pouring.
Measure the resin first using the cup: Fill the 1 gram measuring cup to the level you determined for the resin, then transfer it to your mixing cup. Tap the cup gently to level the material and avoid air pockets. Do not pack or heap the cup; a level fill keeps your ratio consistent.
Measure the hardener with a separate cup: Using a second 1 gram measuring cup (or a clean one), measure the hardener to its correct level. Add it to the resin in the mixing cup. Using the same unwashed cup for both parts can skew the ratio—keep them separate.
Mix thoroughly for at least the recommended time: Stir slowly for the full mixing time specified by the epoxy manufacturer, scraping the sides and bottom of the cup. Avoid whipping in air, which creates bubbles that weaken the bond. Set a timer; under-mixing is a common cause of tacky or weak cured epoxy.
Apply within the working time: Use the mixed epoxy immediately for your rocket assembly, whether you are bonding fins, centering rings, or launch lugs. Discard any leftover epoxy after the working time has passed. Mix only as much as you can apply within the working time to avoid waste.

Product facts

1 Gram Measuring Cup: Measures 1 gram increments for black powder ejection charges. These same 1 gram increments let you portion small epoxy batches consistently, though you must verify your epoxy's ratio by weight.
1 Gram Measuring Cup