Every RFQ that arrives at the workshop gets the same treatment: Clark reads the file, works through a fixed checklist, and answers within 24 hours on a working day. The answer is not a price alone. It is a short written read on whether the part can be moulded as drawn, and what would have to change if it cannot.
The six things on the checklist
1. Application and failure mode
What the part does decides which features are critical. A masking plug that has to survive a cure cycle and then be pulled off by a gloved hand has different priorities from a liner that folds thousands of times. If the application is not in the email, the review starts with a question rather than an answer.
2. Wall thickness and section change
Silicone shrinks as it cures, and thick sections shrink differently from thin ones. A wall that steps from 1.2 mm to 4 mm will pull a sink mark or a void at the junction. Where the step is unavoidable, we plan the cavity around it; where it is accidental, we say so on day one.
3. Undercuts and demoulding
Silicone is flexible, so modest undercuts can often be stripped off a core. "Often" is the word that gets projects into trouble. The review states which undercuts strip cleanly, which ones need a split cavity, and which ones will tear at the corner after a few thousand cycles.
4. Parting line placement
On a sealing face, the parting line is a leak path. On a visible consumer part, it is a cosmetic complaint. The line has to be placed where the flash can be trimmed without touching a functional surface, and that decision belongs in the drawing review, not in the first sample meeting.
5. Tolerance stack
A tolerance that is comfortable on a 20 mm plug may be unholdable on a 4 mm lip. We check the stack against the feature that actually mates with your assembly, and we say which dimensions we will measure at first article.
6. Documents and declarations
If the part needs a declaration, the review names it exactly. Food-contact obligations differ between a baking mat and a coating-line plug, and a declaration that arrives after tooling is a schedule problem, not a paperwork problem.
The 24-hour answer is a fit opinion, not a physical sample. It tells you where the risk sits before you spend money on a tool.
What the reply looks like
- Fit risks, ranked: what will fail, what might fail, what is worth watching.
- Open points, written as questions with a suggested default so the thread does not stall.
- Tooling basis: cavity count, parting line, expected sample date.
- Lead time that applies: 30 days to first article for a new tool, then ships in 10 working days once approved.
Light customization — colour, laser marking, durometer, packaging — is quoted in the same reply when the part already exists and only the variant is new. That path starts at 300 pieces per variant and adds three days.
What it cannot do
A fit review cannot replace a physical sample, and it cannot guarantee a tolerance that depends on how the part is installed. It is a filter, and a cheap one: the point is to spend the argument on paper, where a change costs an email, instead of on steel, where it costs a month.