LANDING GEAR MAINTENANCE, CORROSION, PAINT, DONUTS, ETC

[DCarlton]

Ideally, I'd like to have my landing gear disassembled, stripped and repainted with new hardware and the donuts replaced.  However, I'm concerned about opening an unnecessary can of worms to address surface corrosion that's currently only cosmetic.  A local paint shop has offered once before to strip and paint the gear on the airplane without disassembly.  What's the prevailing choice / recommendation?  Prep and paint the steel parts on the airplane or dissemble and coat / paint?  Any idea how many hours it takes to remove and reassemble the main landing gear and what's the risk of not getting it dialed back in correctly if a MSC does the work? Thanks.

[alextstone]

I just painted my nose gear truss in place... It was not that difficult.  Any decent paying shop skills be able to do it.  Make sure it's impeccably cleaned of grease and dirt first

 

Alex 

N1084U

[DCarlton]

57 minutes ago, alextstone said:

I just painted my nose gear truss in place... It was not that difficult.  Any decent paying shop skills be able to do it.  Make sure it's impeccably cleaned of grease and dirt first

 

Alex 

N1084U

Nice to hear from Hattiesburg.  Thanks.  My wife went to Southern.  

[47U]

4 hours ago, DCarlton said:

What's the prevailing choice / recommendation?  Prep and paint the steel parts on the airplane or dissemble and coat / paint?

On an airplane built in 1967, if the gear has never been apart I’d vote for disassemble, inspect, and replace any hardware (bolts and bushings) that show wear.  

An MSC would be expected to minimize the hours required (compared to my first-time experience).  There shouldn’t be any concern getting the gear reassembled and ‘dialed in’ back on the airplane.

I went through my nose gear and steering horn last summer.  It needed serious cosmetic attention.  LASAR rebuilt the steering horn (which was shot) and sold me a truss (‘STRUCTURE, Upper Gear’ in the IPC) and took my old one for a core.  It had some small dents, questionable if they were really out of limits, but for future resale now there’s no question on its serviceability.  I could have got a truss from Mooney (for more money), but I wanted the steering stops.  Your shock towers (RETAINER, Shock Disc) are probably corroded to the point you need to replace them.  I’ve never heard of one failing, but it could be a really bad day if it did fail, potentially enough damage to total the airplane, especially if it’s the nose gear that failed.  

My 2 cents… good luck.

 

[Falcon Man]

If you decide to have the noes gear rebuilt and painted, consider powder coat paint!

[N201MKTurbo]

The difference between changing the pucks and completely disassembling the gear isn’t that much. Stripping and painting is tedious but not difficult. I have done it like 5 times. Use paint stripper, then scrapers and wire wheels and finish in the blast cabinet. In the past I would just prime with zinc chromate, but those days are gone. So you will have to find a good paint system. Painting tubes is tedious too, but the results are awesome. Buy all new hardware and bushings and you will have essentially new gear.

[DCarlton]

7 hours ago, 47U said:

On an airplane built in 1967, if the gear has never been apart I’d vote for disassemble, inspect, and replace any hardware (bolts and bushings) that show wear.  

An MSC would be expected to minimize the hours required (compared to my first-time experience).  There shouldn’t be any concern getting the gear reassembled and ‘dialed in’ back on the airplane.

I went through my nose gear and steering horn last summer.  It needed serious cosmetic attention.  LASAR rebuilt the steering horn (which was shot) and sold me a truss (‘STRUCTURE, Upper Gear’ in the IPC) and took my old one for a core.  It had some small dents, questionable if they were really out of limits, but for future resale now there’s no question on its serviceability.  I could have got a truss from Mooney (for more money), but I wanted the steering stops.  Your shock towers (RETAINER, Shock Disc) are probably corroded to the point you need to replace them.  I’ve never heard of one failing, but it could be a really bad day if it did fail, potentially enough damage to total the airplane, especially if it’s the nose gear that failed.  

My 2 cents… good luck.

 

Nice looking nose gear!  Did you get a reasonable turn round time from LASAR?  

[DCarlton]

6 hours ago, N201MKTurbo said:

The difference between changing the pucks and completely disassembling the gear isn’t that much. Stripping and painting is tedious but not difficult. I have done it like 5 times. Use paint stripper, then scrapers and wire wheels and finish in the blast cabinet. In the past I would just prime with zinc chromate, but those days are gone. So you will have to find a good paint system. Painting tubes is tedious too, but the results are awesome. Buy all new hardware and bushings and you will have essentially new gear.

Any idea how many hours you would guesstimate on the high side?  Disassembly would be great as long as Its low risk and we don’t create problems in the process.  

[DCarlton]

6 hours ago, Falcon Man said:

If you decide to have the noes gear rebuilt and painted, consider powder coat paint!

I like the idea of powder coat but years ago the Navy wouldn’t allow powder coat on exterior structural components because it’s somewhat porous.  They required epoxy primers and urethane top coats if I remember correctly.  Not sure what would be best for the landing gear.  Powder coat my be more durable?  

[N201MKTurbo]

1 hour ago, DCarlton said:

Any idea how many hours you would guesstimate on the high side?  Disassembly would be great as long as Its low risk and we don’t create problems in the process.  

An hour or two to disassemble all the gear. Two or three to put it all back together. About a week to strip and paint it all. 

[N201MKTurbo]

BTW, I had an FAA inspector say you cannot inspect powder coated assemblies for cracks. If there is an inspection requirement, he said the powder coating needs to be stripped and reapplied to do the inspection. 

[shawnd]

+1 When I bought my plane, I had Frank at Chandler AZ repaint my landing gear. He had also mentioned that powder coating is not a good idea as it can hide cracks and recommended urethane paint for resiliency. Worked well.

[A64Pilot]

13 hours ago, Falcon Man said:

If you decide to have the noes gear rebuilt and painted, consider powder coat paint!

Ref powder coating, Maule went to powder coating of the fuselage and motor mount a couple decades ago. The aircraft on floats in the Bahamas had serious airframe corrosion in 5 or 6 years before they did, once they were powder coated, then the corrosion pretty much stopped. Of course on a Maule the only way to get to the tubing is to remove the fabric, a really expensive proposition.

So I had Moultrie Manufacturing, the same guy who did Maule powder coat the Thrush fuselage, engine mounts and landing gear etc., and that also pretty much stopped steel corrosion on the Thrush.

‘As far as crack detection that’s incorrect, at least on the powder coat Moultrie Manufacturing uses, it’s a bright white “anti graffiti” powder coat meant apparently so that spray paint can easily be removed. In the event of a crack you will see a very obvious rust line on the bright white surface and on a Thrush you will most likely see linseed oil leak out. Cracks are more easily found than on the Navy Grey paint Thrush used to paint their fuselages.

If I had my gear off I’d certainly send it to Moultrie manufacturing and get the same powder coat used by Maule and I hope Thrush still. It’s good stuff.

Ref being porous, maybe it used to be or maybe this special anti graffiti powder coat isn’t where normal is, but I know it removed the yearly maintenance of cleaning rust spots off of the Thrush fuselage and repainting. The Thrush is unusual as all the skins on the fuselage are just Camloced on, so 10 min and you’re looking at the tube frame with the side skins removed. 

Edited March 30 by A64Pilot

[47U]

12 hours ago, DCarlton said:

Nice looking nose gear!  Did you get a reasonable turn round time from LASAR?  

It took LASAR a couple months to ship the upper structure.  They only do a handful of cores at a time and there was a wait list.  I got it into my head that I had made the list for one batch, but the sales dept. overruled the production dept. and I slipped to the next batch.  It’s involved, welding in new tubes, heat treating, painting, all done by subs.  I don’t think though that this effort got caught up in LASAR’s paperwork issues with their FSDO last year (speculation).  Back then I had to send the steering horn back for inspection and a signature, but since I was waiting on the upper structure it was a non issue for me.  LASAR’s communication with me was fine throughout.

I got a quote for 3-4 weeks lead time from Top Gun for a factory upper structure, but (I think) it was about 40% more the money, and I wanted the steering stops.  Maybe I should have called around to other MSC’s to get a quote, each sets their own markup on factory parts.  

With any paint job, preparation of parts is key.  I took the box of parts to a local place the bead blasts and powder coats.  It was .1 amu to bead blast, which I think was worth my time and no aggravation.  I did remove the grime off the parts first with the heated parts washer at the Beale auto hobby shop.  I used a ‘zinc chromate’ (according to the MSD) primer from Amazon.  But, it’s not in listed in my purchase history, so maybe the EPA caught up with them and it’s not available anymore.  The 2k topcoat was also from Amazon, ‘Samurai’ for marine applications.  

Edited March 30 by 47U
Corrected the cost for the factory upper structure.

[DCarlton]

10 hours ago, N201MKTurbo said:

An hour or two to disassemble all the gear. Two or three to put it all back together. About a week to strip and paint it all. 

Want to do it 6 times?  :>  

[DavePage]

10 hours ago, N201MKTurbo said:

BTW, I had an FAA inspector say you cannot inspect powder coated assemblies for cracks. If there is an inspection requirement, he said the powder coating needs to be stripped and reapplied to do the inspection. 

Also, rust can progress underneath powder coat, as opposed to paint, it shows through.

[DavePage]

1 hour ago, 47U said:

 I used a ‘zinc chromate’ (according to the MSD) primer from Amazon.  But, it’s not in listed in my purchase history, so maybe the EPA caught up with them and it’s not available anymore.  The 2k topcoat was also from Amazon, ‘Samurai’ for marine applications.  

I wouldn't be surprised.   We sprayed quite a bit of that back in the 80's, only to find out later that it and imron should be used with a full body protection.

[Kelpro999]

 If you do remove the gear just be prepared to have it on jacks for some time. In the hanger not so bad but outside like I did can be a little unnerving at times.

[Pinecone]

On 3/30/2025 at 1:01 PM, Coachella Bravo said:

I wouldn't be surprised.   We sprayed quite a bit of that back in the 80's, only to find out later that it and imron should be used with a full body protection.

The big thing with all polyurethane paints is that you should be using supplied air respiratory protection.  The catalyst is not stopped by any air purifying respirator.

[A64Pilot]

On 3/30/2025 at 12:51 PM, Coachella Bravo said:

Also, rust can progress underneath powder coat, as opposed to paint, it shows through.

No, if there is rust under powder coat it will bubble up just like it does paint, I think your thinking of primer when you say it shows through.

Thats why it’s important to bead blast just before you paint or powder coat. Ideally you go from one directly to the other.

Now I’ve never lived in the rust belt, but bet money people that do know exactly what rust under paint looks like.

[A64Pilot]

3 hours ago, Pinecone said:

The big thing with all polyurethane paints is that you should be using supplied air respiratory protection.  The catalyst is not stopped by any air purifying respirator.

ALL of the kids in the paint shop around 1983 or so at Hunter Army Airfield failed their Liver function tests, because they had been painting Imron on landing gear for Army fixed wing aircraft with only dust masks and eye protection. I say kids because they were in their 20’s.

 

[akb3]

Mooney experts, what am I dealing with here. Painted over dirt, or corrosion? Thanks. 

Edited April 20 by akb3
Spelling

[N201MKTurbo]

6 minutes ago, akb3 said:

Mooney experts, what am I dealing with here. Painted over dirt, or corrosion? Thanks. 

A poor stripper job and repainted over the residue. You should scrub it off till you get to good paint or metal to be sure.

[akb3]

Okay. I’m trying to become a part of the Mooney family and don’t want to dive off into a money pit. Thank you. 

[Fly Boomer]

16 hours ago, akb3 said:

Okay. I’m trying to become a part of the Mooney family and don’t want to dive off into a money pit. Thank you. 

Too late!  Once you own an airplane, it's game over.  Any airplane.