Use the hydrometer to check the isopropyl alcohol (IPA) resin concentration between cleaning cycles, and replace IPA as needed for the cleanest parts. For a smooth, clean surface finish, replace IPA when the O-ring on the hydrometer’s stem rises above the float’s tall wings.
Use the following supplies to replace the IPA in Form Wash:
- Siphon pump, included with Form Wash
- Empty container, suitable for storing up to 8.6 L IPA
- 8.6 L of fresh IPA
Always consult the safety data sheet (SDS) from your isopropyl alcohol (IPA) supplier as the primary source of information for storage, handling, and disposal. For handling Formlabs materials, reference the SDS provided by Formlabs. Combinations of resin and IPA should be handled according to the restrictions of both. For questions, consult the appropriate SDS(s).
About the Siphon Pump
The siphon pump uses gravity to transfer liquid between containers. For optimal flow, elevate the source above the receiving container. Place the rigid tube in the source container and the flexible tube in the receiving container. To initiate flow, squeeze the siphon pump handle several times, then hold. Gradually release the handle when liquid begins flowing automatically.
To assemble the siphon pump, screw the handle (A) into the rigid tube (B) of the siphon pump.
Use the siphon pump to avoid overfilling or spilling IPA. The siphon pump is designed to transfer liquid without splashing. This includes transferring used IPA into empty containers and fresh IPA into the wash bucket.
WARNING: Watch the siphon pump after initiating flow. The flow will continue automatically as long as the source container’s fill level remains elevated above the receiving container.
Changing the IPA
Follow these steps to transfer IPA from the Form Wash into a chemical resistant container that is safely designated for highly-resin-concentrated IPA and to refill the wash bucket with fresh IPA.
1. Remove the wash bucket and inner lid
Start with the outer lid open, the platform mount raised, and the basket removed. Lift the wash bucket forward and upward to remove it from the base. Set the wash bucket on a clean, stable surface, then lift to remove the inner lid.
2. Use the siphon pump
With the wash bucket elevated, insert the rigid tube into the used IPA and the flexible tube into your used IPA storage vessel. Squeeze the siphon pump’s handle several times. Hold and gradually release the pump when IPA begins moving through the pump.
3. Clean the wash bucket – optional
For the cleanest wash, rinse the wash bucket with IPA and wipe with a paper towel, if needed.
TIP: Use separate wash buckets to preserve part color and quality. Maintain separate equipment to meet biocompatibility requirements.
4. Refill with fresh IPA
Use the siphon pump or pour from a container of fresh IPA to refill the wash bucket between the minimum and maximum fill lines.
5. Install the inner lid
Align the front edge of the inner lid with the wash bucket’s edge, then lower the lid directly onto the top of the bucket.
Disposing of Used IPA
Formlabs encourages safe and responsible management of materials and equipment, including IPA. Always consult the safety data sheet (SDS) from your IPA supplier as the primary source of information for storage and handling. Research local laws and options for recycling and disposing of IPA that is used and combined with photopolymer resin.