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AC Discharge Stain Solution

Posted: March 21st, 2024, 6:34 am
by Midnightsun
Most here know the fibreglass around the AC discharge normally gets stained from the water running/trickling over it. I guess if the pressure is on the high side it may shoot out far enough that this is not an issue for some however on Midnight Sun this is not the case therefor each spring the resulting stain/discoloration is removed however it does require some really intense work to get the area back to new condition.

I have 3 AC outlets, the front is at the water line below the antifouling paint and the rear is under the swim platform once again just above the water line into the antifouling paint and both of these are not an issue. It is the central AC discharge located midship about a foot or so above the water line which is staining the white fibreglass.

Last year my wax guy mentioned some boaters have started to install transparent PPF (paint protection film) just around the affected area. Has anyone here done this and if so what is the outcome. Going to try it this spring after cleanup just before launch.

Are there any other solutions that you know of or have heard about?

Will post some pictures on this thread once PPF is installed unless someone can point me to a better solution.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 8:29 am
by KyleR
:popcorn:

Preach it brother! I'm cleaning that area often too!! :banghead:

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 8:38 am
by Viper
Have you looked into dripless thru-hulls? Technically they're not dripless but they have a collar that protrudes further out which is designed to divert drips away from the hull. Seachioce has a line called "Mega-Flow", there may be others. Don't know how effective they would be for your application but worth looking into. Some boat manufacturers are using this design exclusively now for all their discharge thru-hull installations.

Here is an example on Amazon...
https://www.amazon.ca/SEACHOICE-Mega-Flow-Dripless-Stainless-Streaking/dp/B07CT9L8YH

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 8:57 am
by Midnightsun
Did not know those existed, thanks. Looks similar to dripless condiment bottle configuration. Will take a peak at how difficult it will be to access and remove the existing unit. May choose to go with one of those and do PPF.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 9:05 am
by Viper
Why don't you try 3D printing something you can glue onto your current fitting to see if it would do the trick? I've also seen guys stick thin walled tubes into the fitting's opening to extend the discharge out further. It would reduce the size of the opening but whether that would affect the efficiency of the AC unit or not is something you'd have to assess during operation, it may not affect operation that much.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 9:21 am
by tomschauer
if you spray Starbrite rust stain remover on the stain, it disappears in about 4 minutes.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 9:41 am
by Midnightsun
Viper wrote:Source of the post Why don't you try 3D printing something you can glue onto your current fitting to see if it would do the trick? I've also seen guys stick thin walled tubes into the fitting's opening to extend the discharge out further. It would reduce the size of the opening but whether that would affect the efficiency of the AC unit or not is something you'd have to assess during operation, it may not affect operation that much.


Not a bad idea, could make it tight enough to press fit it in, just a sleeve with a dripless lip on the other end.

Need to see what I am faced with on the boat first which is going to be a few weeks away at best. If the existing thru hull is of the straight variety as opposed to a 90 degree bend then the off the shelf solution you pointed to will be the easiest and most professional way to go and that's also assuming easy access.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 9:45 am
by Midnightsun
tomschauer wrote:Source of the post if you spray Starbrite rust stain remover on the stain, it disappears in about 4 minutes.


It's not just the stain, the fibreglass turns mat like which is the difficult part to bring back.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 11:15 am
by tomschauer
Midnightsun wrote:Source of the post It's not just the stain, the fibreglass turns mat like which is the difficult part to bring back.

I have the staining problem, but not a fiberglass matting problem.

Re: AC Discharge Stain Solution

Posted: March 21st, 2024, 11:18 am
by Midnightsun
tomschauer wrote:Source of the post I have the staining problem, but not a fiberglass matting problem.


I will take a picture of it when I eventually get to the boat so you will see what I am talking about. This only occurs around the AC outlet in question.