EastCoastSail said..saltiest1 said..
Brake cleaner is your friend. We constantly use it on the windfarms for old and new grease removal and is very efficient.
I hope the wind turbines are epoxy resin and not cored. Both types of brake cleaner can damage cured polyester resin and, more seriously, core foam. How badly depends on which brake cleaner and which foam.
(from SDS data):
1. Non-chlorinated brake cleaner is mostly acetone (typically 70–90% acetone), with heptane, naphtha, and sometimes toluene, xylene or methanol, plus a CO₂ propellant.
2. Chlorinated brake cleaner uses perchloroethylene (tetrachloroethylene) as the main ingredient, and older/aggressive formulations may contain methylene chloride (the active in most paint strippers).
On polyester resin (cured GRP/gelcoat): Prolonged contact or pooling is a a problem. Acetone softens and crazes gelcoat and the resin surface, and chlorinated types (perc, and especially methylene chloride) are aggressive to cured polyester.
The real risk is you have foam core (less likely in the bilge):
PVC foam (Divinycell, Airex, Klegecell): attacked by acetone and by chlorinated solvents — softening, swelling or dissolution.
SAN foam (Corecell): styrene-based, so susceptible to aromatic solvents and ketones.
Polyurethane foam: particularly vulnerable to chlorinated solvents.
The common way to wreck a cored panel isn't the resin skin failing — it's solvent wicking through a fastener hole, hairline crack or thin/repaired skin into the core, where it quietly eats the foam without you seeing it (I did it once on a Taipan Cat 20 yrs ago)
Don't use brake cleaner on or near composite structure, repairs, or any exposed core. For degreasing, isopropyl alcohol (IPA) is far safer and won't touch the foam.
