Priming the Engine mount

[mgregory176]

I requested that my finish kit be shipped with a non-powder coated engine mount. After reading some reports of cracks and looking at standard practices used by the rest of GA I am confused why Vans powder coats them in the first place.

Anyway, Does anyone have any experience with the PTI line of products? The PTI sales rep suggested Polyamide solvent primer or a Water reducible epoxy primer. According to the spec sheet both seem suitable for an engine mount application. Just looking for opinions/suggestions.

Thanks,

-Mike

[SHIPCHIEF]

I'm converting my RV-8 to an O-360 with a conical mount. These are made nearby in Tacoma, so I can pick it up about 2 weeks sooner than waiting for it to pass thru VANs and get powder coated.
I'm planning to give it an acid wash and prime it with PPG DP epoxy primer, in whatever color I have left over from building the plane.
That stuff is awsome in it's toughness.
Yes, it takes more work than some other systems. For me, it's worth it.

[JonJay]

I do not know the product you are contemplating using. I will second the PPG DP product although it is not as good as the old stuff the EPA or whomever wouldn't allow anymore.
While Acid Etching is going to clean and prep, PPG DP doesn't need anything other than a clean surface. I would scuff it up to promote adhesion and use a good cleaner wax/degreaser. PPG's DX330 is a very good product but expensive. I use Kleen Strip Prep-All with good results.
The bottom line, make sure it is clean...
Regardless, it will not be as durable as Powder Coating. It is still plenty tuff once it is fully cured though.

[David Paule]

I have a powder-coated engine mount on my Cessna 180 and right now it has just over 600 hours since it was powder-coated.

The paint has been damaged by the heat in the engine compartment, even with heat shields appropriately placed. The damage is significant discoloration. It hasn't cracked yet.

As a result of this experience, I'm not going to repeat this on my RV-3B. I'll use a decent high-temp engine paint for that.

I also had the baffles powder-coated white. They get dirt that's nearly impossible to wash off. In a couple small areas the paint's cracked and peeled away from the baffle. Don't think I'll do that again either.

Dave

[flyingriki]

Just finished putting LPS3 in my tubes and plugging them with drive pins. Then touched up each screw head with clear to seal them. Am I the only one fussy enough to do this?

[SHIPCHIEF]

Rik;
I can't answer your question, but I do know most of the engines in my life spew so much oil nothing could rust in their proximity
Maybe, just maybe this time things will be different....
I don't like oil on the cockpit floor!

[GLPalinkas]

Originally Posted by SHIPCHIEF

I'm planning to give it an acid wash and prime it with PPG DP epoxy primer, in whatever color I have left over from building the plane.
That stuff is awsome in it's toughness.
Yes, it takes more work than some other systems. For me, it's worth it.

+3 on what everyone has said about PPG epoxy primer. My build was early enough that Van's didn't supply powder coated engine mounts. I wouldn't use one if I was to build now for all the reasons cited here on VAF.