powder coating masts

[luso]

Hello! We have two masts that were inodized about 15-20 years ago so even though the masts are still in good shape the inodize is not. My wife and I were thinking of taking the old inodize off via sanding and then painting them. After going to the boat show we found a company that would actually inodize the masts professionally and then they suggested to powder coat on top. My question is would the powder coat stick to the inodize? I would really appreciate any input/advise from you guys. Thank you, Luso

[alaskatrawler]

I would repaint the mast. The trouble with powder coat is once it gets chipped it is hard to repair to look good. I would sand the mast down to bare aluminum and re anodize it, then refinish with a quality polyurethane.

Dan

[t_birder]

Hey there Luso,
I realize this is an older post, but I just joined today. I don't know much about sailing masts, but we have had quite a few folks use a chemical called Sharkhide to seal them with apperant good results.
Hope this helps,
Clint

[tootallsailor]

Hello Loso
I would agree with Alaskatrawler, I have not done powder coating to masts, put on all other types of ironwork I have. When it fails you will probably have to sand and paint it or strip it down and re powder coat it. I have had powder coating on aluminum fail weeks after it was done!

[Jack D Davis]

Tootallsailor. Under what conditions did your powder coating on aluminum fail? How did it fail? How was it prepared? I built a 15' driveway gate for a customer. He had it powder coated professionally. It's been about a year now and so far, so good.

[tootallsailor]

Hello Jack,
We built 5 prop guards for altralite aircraft. The powder coating was done professionally and it was within the first week that the powder coating on one of the guards started to fail. Within 3 weeks all five were sowing signs of cracking and chipping. The altralites were flown an average of three hours a day. All were x-rayed to see if the failing was in the aluminum, but it was not. The prop guards are still in use today (five years later)

[Jack D Davis]

Wow! Quick reply. Thanks. My best guess would be preparation. I don't know how the driveway gate was prepared, but I suspect it was blasted, probably with beads rather than sand. That's only a guess, though. I think I'll go by and check to see how it's holding up.

[tootallsailor]

I think with any finish it is the steps you take to prepare the surface before the finishing. I believe the prop guards were acid etched.

[Thunderhead19]

Bubba thinks that aluminium is affected in three ways that inevitably caused the powdercoat to fail. He says that the powdercoating was good and thick, and the Aluminum's modulous of elasticity exceeds that of the powder coating. He also says that that stuff is baked on, so that it solidified when the aluminum was thermally expanded, then went outside where the alli shrank "like a dick in the pool". The other thing he said was that anything mounted in the immediate vicinity of a prop or a motor will tend to vibrate and he thinks that that caused shear between the coating and the substrate. At least I think thats what he meant.. he tends to point and grunt instead of using multi-syllable words.