Check Your Lag Bolts And Engine Mounts

[a64pilot]

If you have bolts and nut plates and are concerned about possible loosening, then put a slippage mark between the bolt head and the mount, it’s just a paint stripe although there is a special “anti sabotage lacquer” you can buy, simple red fingernail polish or your favorite color works just as well, fingernail polish as it dries fast and thick and comes in a small bottle complete with a brush.
You’ll know at a glance if a bolt has loosened as the paint mark will be broken or misaligned.

[maxingout]

I probed the lag bolt holes with a fine pick, and the wood seems in good condition. No mushy wood or rot discovered. For that I am grateful.

[a64pilot]

I’d still be tempted to thin some epoxy and let it soak into the wood, cure and drill it out, just to waterproof the wood for the future.
Model airplane builders use what they call 20 min epoxy for fuel proofing firewalls etc. it’s very thin almost as thin as water and soaks in really well and is slow cure.
Probably blasphemy, but is have thinned epoxy with 90% isopropanol alcohol before with success.

Or maybe let it soak a while but shoot the lag bolts in with the epoxy wet? Just use good SS bolts?

[wsmurdoch]

In December I had all four of my engine mounts replaced. Of the eight lag screws attaching the mounts to the engine beds, one was corroded away. The maker of this screw was not proud enough of his work to place his name on the bolt head nor was he helpful enough to indicate the alloy. All of my replacement screws are marked.