SonexBuilders.net

Today I spotted what looks like cracks the engine mount. I'm not yet 100% sure, yet, that it's not just a scratch in the powder coat. This makes me think of all sort of questions for the collective group (those with experience anyway).

-Short of pulling the engine and removing the powder coat how can I tell this is not a scratch in the powder coat?
-How do I know if my mount is thin or upgraded thick wall?
-Is this horizonal (almost) X-brace under the back of the engine (V-dub) an area of historical cracks?
-If a new mount is in my future, I'd be tempted to install a ULPower and sell my FWF. How has it gone for folks with the ULP in the Sonex-A's?

Brock
If im looking at it correctly, i don't think a crack can migrate across a weld.

How about torque seal across the suspected crack?

You could use a Die penetrant kit that will help determine if it is or isn't a crack, a cheap and non destructive test.

looks like scratches to me.

I tend to agree...it looks like simple scratches in the coating to me as well. Can you catch the scratch/crack with a fingernail? You may be able to use an emery cloth or some fine sandpaper to sand down the scratch and see if it disappears, and if you get to the metal, prime and paint that spot for rust protection.

The one in the first picture looks like it could be more than a scratch to me. At the very least, I'd carefully grind off the coating on either side of that enough to tell for sure.

It's not the usual place they crack but that doesn't mean you can't be first. I agree with Murray; buy a die penetrant kit. Even if you rub the powder coating back you might hide a crack with debris. Small cracks in steel can be hard to spot.

Peter

I saw several reports via web search that Permatex Gasket Remover does a number on powder coat. Bought some on the way to the hangar today but it was in a small enviromental looking spay pump not the traditional aerosol can. It did a nice job cleaning the surface of the powder coat. Wasted $20. I really don't want to use abrasive if I don't have too. Tempted to use a small butane torch.

I believe I still have a can of dye penetrant and developer on the shelf some place. Once step at a time.

Too bad I didn't spot this last week before my failed attemp at fixing an oil leak.

I had found a crack on my mount last August during my annual. Prior to that I was flying and was wondering why I could not hold my altitude. Thought it was slack in the flight controls until I pulled the cowling and found this.


Ended up pulling it apart and did the Fix which turned out great.