How to get the best from your impregnation plant

Testing with US MIL-I-17563C Test Rings

If possible, first weigh the test ring to 0.1g precision and record.
Secure the ring to a component about to go through your plant.
Carry out a normal impregnation cycle, washing and curing.
Remove ring and re-weigh and record. Well applied high quality impregnant will increase the weight of the ring by as much as 1 gram.
Clamp into pressure test fixture and apply air pressure of approx 3.5 bar. DO NOT SUBMERGE IN WATER AT THIS STAGE.
Observe the ring when pressure is applied and note if anything exudes – this is likely to be uncured sealant.
If there is no such exudation, immerse in water and observe any leakage.
If the part should leak:
1. Compare rate of leakage with the leakage chart shown below and record.
2. Return the leaking ring to the plant and carry out one further impregnation, test and observe again as above.

In accordance with the US MIL-I-17563C approval, the ring should be sealed completely. The US MIL spec allows for a second impregnation to seal. A second impregnation should only be necessary where the component is of a poor grade or the system is failing. If the sealant is of good quality and the process is correct, you should get a seal from one impregnation.

Leakage Chart

	0: High Quality Seal		1: Good Quality Seal
	2: Medium Quality Seal		3: Medium/Poor Quality Seal
	4: Poor Quality Seal		5: As If Not Impregnated

Note: Even high quality sealants will fail if the method of processing does not meet the laid down specification.

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