Danger:
Always consult the safety data sheet (SDS) from the solvent supplier as the primary source of information for safety, usage, and storage.
WHITE PAPER
Best practices for washing prints
Best practices for washing prints
Follow Formlabs best practices to achieve the cleanest parts:
- Dedicate a wash bucket to each resin to avoid resin discoloration, depending on which resin type.
- Rinse parts in multiple stages and regularly replace used solvent to achieve cleaner part surfaces that feel less tacky or waxy, depending on the solvent used.
- Consider part size and geometry when washing with the Form Wash and Form Wash L to safely and effectively remove liquid resin from prints.
Notice:
Wear gloves when handling printed parts and surfaces that are contaminated with solvent or liquid resin to prevent skin contact.
Separate wash buckets (optional)
When using a single wash bucket, residue from previously washed parts deposits on part surfaces. If washing materials like Black Resin or Castable Wax Resin in the same wash bucket as White Resin or Clear Resin, some color transfer may occur.
When washing multiple resins in a single wash bucket, replace the solvent more frequently to maintain surface quality. To preserve the best possible surface finish, maintain separate wash buckets for each resin type or for similar colors.
Use a dedicated wash bucket for the following resins:
- Castable Wax Resin (to avoid color transfer)
- Castable Resin (to avoid color transfer)
- Rigid Resin (to prevent glass particles adhering to parts printed with other resins)
- Ceramic Resin (to prevent ceramic particles adhering to parts printed with other resins)
Notice:
Third-party solutions are not certified for use with Formlabs resins for biocompatible applications. To comply with biocompatibility requirements, only use the Form Wash, Form Wash L, Finish Kit, Form Cure and Form Cure L with the following resins:
- BioMed Amber Resin
- BioMed Black Resin
- BioMed Clear Resin
- BioMed Durable Resin
- BioMed Elastic 50A Resin
- BioMed Flex 80A Resin
- BioMed White Resin
- Dental LT Clear Resin
- Dental LT Comfort Resin
- Dental SG Resin
- Digital Dentures Resins
- IBT Flex Resin
- IBT Resin
- Permanent Crown Resin
- Premium Teeth Resin
- Surgical Guide Resin
- Temporary CB Resin
Rinsing parts in stages (optional)
Revise the workflow to prolong the lifetime of the solvent bath or the amount of use before the solvent needs to be replaced. Consider rinsing parts with a small volume of solvent before inserting printed parts in the wash bucket. The preliminary rinse option will remove most of the resin and keep the solvent in the wash bucket cleaner.
Multi-step process with IPA
When washing prints in IPA, a layer of resin diluted in IPA coats the surfaces of printed parts after washing. As the parts dry, the IPA evaporates but the resin does not, causing the surfaces of the part to feel tacky.
If printed parts feel tacky after the first wash in IPA, rewash the parts in clean IPA. Start the second wash immediately after to prevent residual resin from curing in ambient light.
Multi-step process with TPM and IPA, or TPM and water
TPM does not evaporate readily, and leaves a waxy surface texture on some resins after washing. After the first wash, let the prints drip dry thoroughly before starting the second wash with water or clean IPA to remove the remaining TPM.
Using IPA for the second wash helps remove the waxy surface texture. Using water for the second wash will yield different results depending on the resin used.
Tip:
Consider using fresh solvent in a squirt bottle, like the type included with the Finish Kit, to gently rinse the outer surface of parts and hard-to-reach details. The "squirt bottle method" conserves solvent and can be used after washing parts in a bath.
Increasing the wash time
Tip:
Take care not to exceed the recommended wash times for some Formlabs resins. Read individual material articles for specific wash instructions and always consult the support article Form Wash time settings as the primary source of information for up-to-date wash times.
Recommendations for hollow, concave, large, or long parts and internal channels
Inspect all parts after printing to determine the best washing process. Very small parts may pass through the wash basket and impede the impeller. Larger prints may not fit in certain orientations or may cause the wash bucket to overflow.
Hollows, concavities, internal chambers, and internal channels hold solvent, air, or uncured resin inside.
Take care when removing these parts from the wash bucket to avoid spills. Modify the washing process for parts that are large or long, or have concave surfaces.
| Part geometry | Recommendation |
|---|---|
| Hollow parts |
Design hollow parts with drain holes for successful printing. During the washing process, drain holes allow the solvent to flow inside and clean internal surfaces. Take care when removing hollow parts from the wash bucket. Ensure that the solvent drains out of the part and into the wash bucket before transferring the part to another surface. |
| Internal channels |
Narrow channels, such as those used in micro-fluidic designs, may not drain entirely on their own. Use a syringe filled with clean solvent to flush out internal channels. |
| Concave surfaces, printed and washed on the build platform |
Some parts printed directly on the build platform can trap resin and solvent inside during the wash cycle. Consider removing these parts from the build platform and washing them in the wash basket, or add a second wash cycle after removing parts from the build platform to ensure no solvent or liquid resin is trapped inside. |
| Long parts |
Parts move around with the circulation of the solvent in the wash bucket. Long parts that hang outside the wash basket perimeter may dislodge the machine's inner lid. Check the path of the wash basket and the inner lid to ensure that parts do not obstruct the inner lid when the wash cycle completes and the wash basket raises. |
| Large parts |
Whether washing on the build platform or using the wash basket, consider the maximum capacity of your part washing unit:
Also consider solvent displacement and the enclosed volume of your printed parts. Remove some solvent from the wash bucket with the siphon pump before washing a print larger than these limits:
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