This seems to be a controversial topic for some reason. How do y’all feel about powdercoated engine mounts? I used to work for a Caravan engine conversion company and we powdercoated all our engine mounts, and they were linseeded, and sealed. Never had an issue seeing rust or cracks.

I had the engine mount for my Stinson powdercoated and caught a lot of backlash on it. What do y’all think?




Sent from my iPhone using Tapatalk

For me the only issue with powder coating is its tendency to hide corrosion until it’s well advanced. I’m specifically referring to surface corrosion underneath the coating, all it takes is a tiny microscopic hole or crack to allow moisture in. In the seaplane world we’ve seen this many times over the years. In dryer climes this is obviously less of a concern.

I think it looks great. Same argument can be made about paint and a pin hole.

Where did you catch crap for the powder coat? ISC forum?

Powder coating is a hard and durable paint but a good urethane can accomplish the same thing.
As far as rust under the paint, same thing can be said for a good urethane.

There is a preference among some for white over black as it's claimed cracks can be more quickly identified but a serious inspection with a bright light will expose cracks on any color.

Ford vs Chevy

I think that a freshly powdercoated mount that that had been stripped and cleaned well enough to powdercoat, and even superficially inspected while bare metal, would be way less likely to fail in the next 15 years than a whole lot of the sixty year old mounts belonging to a lot of the guys who will happily tell you what a fool you are for powdercoating one.

Not all powdercoat is created equal. If the people that powder coated your mount know what they are doing and correctly prepared the metal then it's fine.

I've also gotten hell for building a 100% electric airplane. I think people just like to force their opinion on others. As far as I'm concerned they can keep their vacuum gauges.

I believe the issue is the old powder coat systems... I am sure most of the “na sayers” have seen rusting due to the old powder coat systems that have a tendency to crack and flake off... The newer materials are far more superior in coverage and durability... The company I use applies a high zinc primer first before the color coat...

Brian


Sent from my iPhone using Tapatalk

I have painted a lot of things over the years, the preparation is 80% of painting anything. A good powdercoater that is familiar with airplane parts or specific instructions to the powder coater will get a part that is not only airworthy but will outlast most peoples spray on applications.
Most people do not get the paint when conventional spray equipment is used into the hard to reach places. Then sooner rather than later rust develops.

If I can powder coat something I will do it. I do use white on my engine mounts for the reason stated already but for years I used black. If it is already black I would not change it. I love powder coating, drop something off and get it back done for less than I can paint something if you count your time worth anything. The cost of good quality epoxy primer and a urethane top coat are going to be close to the cost you pay for a bunch of powder coated parts.

I see parts painted by people and they usually look subpar unless you know what you are doing.

I just finished welding on the fuselage of my ag plane, had to replaced some tubing that was completely rusted out from the inside. I’ve steam washed and hit that joint with a pick many times, but it finally blew out without any notice. It was thickly painted, no signs of rust until the damage was done.

I like how your powder coating looks, thinner than paint and should be easy to inspect. I’d rather have a properly done powdercoating than thick paint slathered on any day.

As I understand powder coating, the part must be heated to around 450 degrees F to cure the coating.

Anybody out there know if this temperature will affect the yield strength, and ultimate strength of the alloys used in engine mounts?

Perhaps is improves part quality by relieving stresses near weld joints?

The dwell time at high temperature, and the cooling rate could also affect part strength.

Thoughts?

450 is not going to normalize 4130

Frankly, it’s none of my business how you cost YOUR engine mount. You like powder coating? Good for you, go for it.

And I’ll do whatever is legal and appeals to me on mine. Your rig looks good to me, but I’m not the one you need to please....if you’re happy, you’re good.

There’s too much undocumented BS out there as it is. Make yourself happy.

MTV

That looks very nice.

Thanks y’all. Yeah, the way I see it, it’s my airplane that I fly so really it’s my ass if something fails. I figure no ones had an engine mount fail because of powdercoat. If it fails, I’ll eat my words lol.


Sent from my iPhone using Tapatalk

My 2007 National 30 ton truck crane, that I bought slightly used 4 years ago, used powder coating in many areas. It came from Appleton Wisconsin FWIW, and was kept inside when not in use. The powder coating is flaking off, showing established rust underneath. It looks especially bad when viewed from the rear, and it bugs me no end to see my company name on a (partial) rust bucket, that people trust their lives too. No one else has ever commented on this, and I am probably over sensitive. But, I have a friend with a commercial sandblasting biz, and I am going to have him blast the PC off, and I will build it back up with brush applied coat/coats of....wait for it.....good old Rustoleum! Available anywhere, the "rusty metal primer" is great stuff, and all my metal hand rails on my decks are finished in 2 coats of that, NO finish paint, 12 years later it looks like the day i painted it.

Hand painting a steel tube fuselage is THE most onerous job of building, and if I was to build again, I would for sure powder coat it, after reaming out the applicators on exactly how it and when it would be applied, and yes, it would be a light color. I too have heard the process has advanced in recent years, inexpertly prepped and applied it sucks over time, done right it's a huge time saver.

-0-

Dogpilot, solid info. You and I could be friends I bet


Sent from my iPhone using Tapatalk

10 years ago I used powder coating material listed in section 20-76 on page 20.18 of:
https://robinsonheli.com/wp-content/uploads/2017/04/r66_mm_20.pdf
on my engine mount. I like the white topcoat from an inspection perspective, and it still looks great.

As previously stated, successfully coating anything is dependent on proper prep work, to include using the specified zinc-rich, epoxy-powder base coat.