There are several types of epoxy cements that can take anywhere from 5 minutes to several hours to cure partially or fully.
Holding the cemented pieces by hand waiting the duration of the cure time is not practical or accurate. This lesson illustrates a 5-minute workable time epoxy behavior (see video below) and further down, we illustrate the different methods that can be used for keeping cemented pieces in place until the epoxy cures enough.
The video below is taken at a 75 degree F room temperature. The whole process will be slower at lower room temperatures way we expedite the process is by placing the epoxy cartridge in a 140 degree F wax warmer and than place the cemented object in a heated box that is also set to 140 degree F reducing cure time dramatically.
140 degree oven for reducing cure time
140 degree wax warmer for reducing cure time
Keeping Cemented Pieces in Place Until Epoxy
Cures at Room Temperature of 75 Degree F
Gravity is your best friend: In most cases, we use container with PVC pellets to hold broken segments in place to positioning the pieces using gravity where no temporary bonding is require
Resin / PVC pellets seem to work the best for us. One can use rice or sand.
For the pellets, search web for "Resin pellets". The sharp edges type (as shown above) work better than the totally round pellets
Dry run proper placement of the two parts needing cementing
When it stands on it own, place the epoxy on
Temporary bonding methods: At times, using gravity alone to secure broken segments in place may not work. Few temporary bonding techniques are shown below (tape, clay, glue-gun)
If you are unsure it will stay, you always add tape
Often we use clay as shown here or below
There are cases that it is difficult or impossible to place balanced using gravity.
In such case, we use clay to keep the parts matched until the epoxy cures
If clay is not available, tape can be used
Glue gun is also an option although it is a bit harder to remove once the epoxy cures
Filling Large Gap or Missing Piece on Ceramic, Pottery or Sculpture
Small pieces do not hold well on the resin pellets. This example shows how we use clay to position the segments on clay
Segment A is oriented anchored on the clay until segment B can stand on it's own in the correct location
Some more examples of keeping pieces in place
In this example, we use both, clamps and pellets
In this example, we are using double jointed vice to place the plate in the proper orientation - see vice on left
Clamp swivel vise
With heavy and large items, we use, ropes and winches