Syndicate Anodized Aluminum fin block corroding ... WHY ?!

[Glydon]

Ok so I am not a metallurgist by any means however I was under the impression that anodizing aluminum was done to 1) make aluminum parts "pretty" and 2) make them less susceptible to corrosion . I unlike most on this forum do not have the luxury of skiing in fresh water , I ski in brackish water (fresh water river running into salt water tidal estuary) . I have always rinsed my gear after every ride and never had an issue with aluminum until NOW. I LOVE my HO A2 and treat it like a baby , my concern is after just one season in salt water corrosion has started to appear on the fin block and will only get worse. I am looking for advice on how to prevent it without harming the ski (is there anything I can spray on it other than water to counteract the salt without damage to the ski's finish? @savaiusini ) I am afraid it will not look "pretty" for

long. For comparison my natural aluminum fin block on my old Iconn ski still looks as new. PLEASE HELP!

 

[eleeski]

I am not qualified to answer your question regarding appearances - because performance is what matters!

 

As one who skis in salt a lot and brackish water mostly, there are things you must do to keep parts functioning. Anti seize is magic. Purchase it from the auto parts store. Remove every screw (one at a time if you don't want to readjust) and liberally coat with anti seize. Get a toothpick and work some into the hole. Also treat inserts in the ski as well as the fin hardware. Every machine screw. (Note, don't anti seize sheet metal screws - the pointy ones with coarse threads - nothing much helps there. When those fail, epoxy install inserts and anti seize those threads.)

 

When I kept my boat in salt water, I sprayed the engine with WD40. I didn't always rinse but it always got the WD40. Held up reasonably well.

 

Regarding the aluminum, I've had some parts hold up well and some corrode quickly. Anodized and raw. All suffer a bit of corrosion. ACF50 is a corrosion inhibitor for aluminum aircraft that works well and didn't eat the paint or plastic on my plane. Get it at Aircraft Spruce or your local pilot supply store.

 

Finally, if the ski works well for you, enjoy it for how it skis - not how it looks. Fin blocks can be replaced, awesome days on the water can't.

 

Eric

[DW]

@Glydon : unfortunately the anodizing process for your particular fin block is suspect, probably the part was not perfectly clean when dunked in the fluid, similar to fish eyes when painting or it got nicked off during use. You could have it redone, perhaps it can be done on warranty for that part. Zinc chromate primer / paint would protect the surface, but would certainly lack in appearance.

 

[Horton]

If you ski in brackish water and your ski is a number of years old and the fin block, fin and inserts are not completely destroyed I would say you're doing everything you can to preserve it.

[Glydon]

@DW I doubt HO will warranty it is now with the release of the 2018's 6 model years old. @Horton this is the first season of use with only about 10 sets on it in salt water , my old Iconn Sonic C-6 held up to over 10 seasons and no issues . My fins and inserts never corrode, so this was the first time I had seen corrosion on any component. Hence the reason for the surprise , I will continue to use the fresh water rinsing and hope it does not get worse. Thanks to you both.

[MarcusBrown]

@Glydon I have a newer fin block and fin blade I can send you. Shoot me a DM with your details and I'll ship it out asap! Not sure why that is happening on this particular fin block, but lets get you sorted sooner rather than later.

 

MB

[Glydon]

@MarcusBrown you are the coolest ! Thanks man.

 

[Bainesster]

Same thing happened to my fin block on my a3, as a result of skiing 100+sets in salt water per winter

[Glydon]

@Bainesster 100 + sets I could maybe live with , this has had 10 ... I have snowmobiles with anodized aluminum that are towed on open trailers , the anodization looks like new , road salt is FAR harsher. It's ok though I hope the fix is in!