All Aircraft: Where and When to Use Aircraft Solvents

BLUF: Use MIL-PRF-680 and Navsolve (MIL-PRF-32295) per guidance when cleaning aircraft components.
 

Photo by Staff Sgt. Austin Berner
 

This article initially appeared in PS 776 (Jul 17), p. 52-53.
 
For many years, MIL-PRF-680 type II was the approved cleaner for Army aviation components. It was intended mostly as an immersion cleaner but could also be used as a hand wipe cleaner.

But environmental regulations is some areas require a solvent with a volatile organic compound limit (VOC) or less than or equal to 25 grams/liter (g/l). Navsolve (MIL-PRF-32295) was developed as that alternative. Both MIL-PRF-680 and Navsolve are free of hazardous air pollutants (HAPs).

Below are the applications and restrictions for using MIL-PRF-680 and Navsolve. Use this list for guidance on Army Aircraft.

 

Spec	VOC (g/l)	NSN 6850-	Size	Comments
MIL-PRF-680 Type 1	+/- 750	01-474-3202 01-474-3209 01-474-2313	1 gal 5 gal 55 gal	Used to clean parts contaminated wit light dirt, oil, and grease.
MIL-PRF-680 Type II	+/- 750	01-474-2319 01-474-2317 01-378-0698 01-474-2316	1 gal 5 gal 15 gal 55 gal	Most commonly used solvent used to clean Army aviation components for many years.
MIL-PRF-680 Type III	+/- 830	01-474-2318 01-474-2321 01-474-2321	1 gal 5 gal 55 gal	Used when a higher flash point is required.
MIL-PRF-680 Type IV	+/- 750	NA	NA	Not approved for Army aviation equipment. It contains D-limonene which may cause corrosion on flight critical parts.
MIL-PRF-680 Type IV	≤25	NA	NA	Not approved for Army aviation equipment, though approval could be pursued if requested. More expensive than MIL-PRF-32295.
MIL-PRF-32295 Type II NAVSOLVE	≤25	01-606-8356 01-606-8357 01-606-3293 01-606-8358	4 gal 5 gal 15 gal 55 gal	Approved as an alternative to MIL-PRF-680 Type II. The preferred alternative when environmental regulations require ≤25 VOC g/l. Flash point is lower than MIL-PRF-680 Type III. Local safety office must approve NAVSOLVE as an alternative to MIL-PRF-680 Type III before use.