Powder Coat

[jmvolpp]

I've lately been considering a Piper Pacer (in Florida) as an addition to, or replacement for, N44305. The asking price is about 2/3 of what one might expect, relative to the original logs having been stolen, and some fixin' to be done. It's estimated to have about 2000 TT, the 0-290 400 SMOH, and was recovered about 15 years ago, at which time the fuselage was powder coated. Several past threads on the subject say nothing good about powder coating airframes and, should one be so inclined to do so, removal and refinish would not be for the faint of heart. Am I correct in thinking the powder coat to be the kiss of death to this project?

Mike V.

[crispy critter]

Re: Powder Coat

I'm not the foremost expert on powder coating but I do have a small machine and like to use it. I'm going by memory but I think it mostly depends on the type of powder coating they used on the pacer. Some folks early on used a type of ceramic or hard shell powder coating,that is the stuff you want to be affraid of because it is hard to remove and if it has cracked or managed to get moisture inside of it somewhere the tubing will actually rust under the powder coat layer. Very few airplanes that I know of was done with this process so that's a good thing. The best thing to hope for is that someone done it right and used a urathane based powdercoat(that's what I put on crispy),it can be removed with paint stripper and MEK will soften it enough to do repair work if you just need to strip a small area. It also seals the exterior of the tubing just like a urathane based paint. They also used an epoxy based powder coat that was pretty popular and still is. It is not as good as the urathane because it is much more difficult to remove however it bonds to the metal and seals it very well. If it is put on too thick it can crack in places but nothing like the first mentioned process. All in all theres nothing wrong with powder coating if its done correctly and if done correctly it will preserve the steel tubing for a long,long time. Of course a lot of your epoxy and urathane primers and paints now days are just as good and maybe better in some cases but the cost,extra labor,and mess is 10 times more then the powder coating process. Just make sure to inspect it really well. Look for cracks,chips,and peeling in the powder coating. If it is very hard and brittle with areas of cracking and peeling then you might want to rethink it but if there is no rust present under the cracked or peeled areas then you might be okay but you will want to strip it off and have it redone. The fact that it is in florida is reason to be cautious and look closely for corrosion over then entire airframe. Hope this helps.

[N96337]

Re: Powder Coat

Am I correct in thinking the powder coat to be the kiss of death to this project?

Mike V.

As far as I'm concerned, you're exactly right there!! No powdercoat gets through this shop, since I found a tube completely corroded through on a Super Cub, and no flaw in the powdercoat to indicate it. That's some great, tough finish, but as far as I'm concerned, I wouldn't use it on a lawnmower, nonetheless on any airplane that I need to inspect for damage or cracks. The FSDO here shares the same view, and are cracking down on alot of airframes that were done and are now showing problems. Just ask the AirTractor guys (owners and mechanics) how much they like it....but be ready to duck! We did some brake parts on a Goose years ago, and they were a total disaster with corrosion.
Somebody may have good to say about it, but I sure don't. I'd say check with the local FSDO before getting too carried away.
John

[freightpilot27]

Re: Powder Coat

doesn't Maule Aircraft still use powder coat on the fuselage frame?

[crispy critter]

Re: Powder Coat

Yes I believe Maule does use it and I think they still use it on the husky's & super cubs too(unless they have changed processes that I haven't heard about). I totally agree that if its the old stuff you want to stay away from it,but if they used a urathane base powder coat it's no different then using urathane primer/paint. It is just in a powder form when applied and baked on for a quicker and faster finish. It is just as flexible as the something like ranthane or aerothane and pretty much the same stuff but it is just a little more scratch resistant and carries the same chemical resistance. Also the epoxy based is not too bad either but that old hard shell plastic or ceramic type stuff is bad news....I've seen that stuff crack and peel it like a hard boiled egg shell to find nasty rusted tubing under it and until you start to peel it you would never know there was anything wrong under it. The problem is that older stuff did not bond or stick to the steel,it simply dried around it and unless it bonds to the steel it will not protect it. I would find someone who knows what they are looking at with the powder coat to inspect it closely before I bought it.

[jmvolpp]

Re: Powder Coat

Thanks, guys, for all the input. I've since learned that a PA20 and a PA22/20 may soon be available locally, but haven't completely closed the door on the FL PA20 yet. Just in case it can be determined, is there a particular brand name for the not-recommended, older dry-around-the-metal powder coat and the maybe-recommended, newer dry-onto-the metal type?

Mike V.

[astjp2]

Re: Powder Coat

Powdercoat is the least of your problems, That o-290 is a boat anchor. They should pay you to take that O-290 from them. If it was an O-235 or O-320, then its an ok project. Try and buy rings or bearing for that engine will cost the same as a completed O-320 from ECI. Tim

[wlas]

Re: Powder Coat

Almost every airframe from airframes Inc. gets powder coated. I've been having them done for the last twelve years and most of the struts,jury struts,gear legs, etc, never ever have I had a problem.

[jdoran]

Re: Powder Coat

Our company does a lot of powder coating.

Remember that powder coating is only as good as the surface underneath it. If it's not clean when the powder goes on, it is merely window dressing over corrosion.

I think a lot of tubing failures happen from inside out-when airframes get water inside. Again, the powder coat surface is not doing anything to prevent that.

The upside is that powder is a much tougher finish than paint, but that is also it's downside on aircraft tubing because it hides all of the visual signs that we would look for to indicate corrosion (bubbles under paint, etc)

I think that powder coating an airframe when it is brand new is better than one that is being re-done because it is easier to know and control the underlying conditions of the steel. However, remember that you must be extra vigilant in looking for corrosion under a powder coated surface.

[N96337]

Re: Powder Coat

The upside is that powder is a much tougher finish than paint, but that is also it's downside on aircraft tubing because it hides all of the visual signs that we would look for to indicate corrosion (bubbles under paint, etc)

That's what I was trying to get across, John. Well said!
John