| Requirement | Epoxy submission | Vinyl ester submission |
|---|---|---|
| System identity | Resin and hardener grades; prescribed mix ratio | Resin grade and prescribed cure package |
| Process fit | Viscosity, working window and cure schedule | Viscosity, gel window and cure schedule |
| Chemical service | Grade-specific recommendation for exposure | Grade-specific recommendation for exposure |
| Construction | Reinforcement, bond interfaces and cure evidence | Reinforcement, corrosion barrier and cure evidence |
| Release evidence | Approved laminate tests and batch documents | Approved laminate tests and batch documents |
Specify the exposure as an operating envelope
Provide the fluid composition, concentration range, normal and upset temperatures, cleaning cycle and expected contact duration. The Derakane selection guide distinguishes resin grades and chemical-service conditions. Use such a guide as a screening reference, then obtain a current written recommendation for the actual duty and laminate. Do not transfer a chart entry to an unspecified resin from another manufacturer.
Qualify the process as well as the chemistry
Ask the fabricator to describe how mixing, reinforcement wet-out, cure and any post-cure will be controlled. Record storage limits and the manufacturer's instructions for the complete system. Agree which production records and acceptance measurements must accompany each batch. Substitution of a hardener, accelerator, filler or reinforcement requires review of the approved construction.
Keep trial approval tied to the offered grade
Review representative laminates or parts made with the proposed production method. Separate appearance and dimensional approval from the required chemical, mechanical or bond evidence. The purchase order should identify the approved system and notification requirements for changes. If the evidence does not cover a controlling condition, record that gap and obtain the necessary technical evaluation before approval.
Sources and scope
These references support the stated technical context. The purchasing checklists are GetFRP recommendations. Manufacturer documents do not certify other suppliers' products.
- Derakane: resin selection guide for chemical resistance
Grade- and exposure-specific selection context; current manufacturer confirmation remains necessary.
