Preventing Hull Yellowing

[Fam-man]

I have a 98 Nautique with a white/green/gray colour scheme. Last year by the end of the season and again this year by the end of the season the white on the bottom of the hull turned yellow. I've got a hull cleaner that takes it back to white but its a harsh chemical and I'd rather not use it.

 

What might be causing the hull to go yellow? Is there any way to prevent it?

 

The boat is only in the water and sun when its being used. After use it is wiped down and parked in the garage.

 

Thanks

[paco]

My 1993 mc does the same thing. I heard scrubbing bubbles would remove the yellowing, but it didn't work in my case. As far as prevention, a good wax should at least slow it. It helps mine.

[Fam-man]

@paco I used a product called starbrite hull cleaner. Just wipe on, let sit for 30 seconds and rinse off, magically the hull was white as new. Tells me it is nasty stuff.

 

There's been some discussion about another product on this site, cannot remember what it was.

[ScottScott]

Itll happen from the water line down (your green/gray may disguise part of that on your boat.) I'm not sure there is a real way to prevent, a good coat of wax, and would probably still have to do a full wash every time you use the boat. I get it also, and am generally in a pretty clean lake. I use the starbrite, which I believe is marina safe. If I run out and don't want to wait to order/or go somewhere that carries the starbrite, atwood also makes a hull cleaner that is available at walmart, it may be a little harsher (but I think it works a little faster than the starbrite.)

[storm34]

We're in a mud bottom lake and everyone fights this problem. Cleaning with acid (Starbrite or The Works toilet bowl cleaner) followed by a coat of wax are good short term solutions. Haven't had any issues with using the acid but don't let it sit on other surfaces for long periods of time (trailer paint, concrete, running great etc).

 

The only way I've been able to keep boats clean of long periods of time is to buff the bottom. We use the following products in this order and it seems to last at least two summers.

 

3M Super Duty Compound on a 1" pile wool pad, 2x

3M Perfect-It II Compound on a 1.5" pile wool pad, 1x

3M Finesse-It II Finishing Material (this is a polish) on a wool/acrylic blend polishing pad, 2x

Collinites 925 wax, by hand with a microfiber cloth

 

It sure is a PITA to buff everything and give it a few coats of wax but you'll be skiing while all the neighbors are cleaning.

[sunvalleylaw]

@storm34 , I don't have the same mud issue as you, but have some left over stains on my new to me boat from the prior owner, just in the bunks area. Everything else has been buffed out. I plan on figuring a way to get the bottom up off the bunks, and do the StarBrite or Ez On Ez Off, then use some compound and polish as you suggest, and then finish off with Griot's Garage Poly rather than Collinites Wax. Saw a comparison of the Collinites and the Griot's poly on the Malibu forum and it looks like a decent option.

[gregy]

Hull cleaning Thread. I bought some of the hc-1 and it worked. There's a lot of info if you look through the thread.

[TallSkinnyGuy]

I wonder if a polymer sealant on the bottom would hold up better than traditional wax and therefore be better at preventing the yellowing?

[Dacon62]

On a muddy lake. Mix this at 3-4 tbsp per liter (1/4 gallon) spray bottle

Spray on and brown comes right out then spray off. No scrubbing required.

[sunvalleylaw]

@Dacon62 Is it acid based? Fumey? Ok if it is. Just want to know what to expect.

[thager]

Once clean hit it with Nu Finish. I no longer have to deal with the staining I once had with regular waxes. Been using on my boat for many years.

[TallSkinnyGuy]

Nu Finish is one of those Polymer sealants I mentioned.

[Dacon62]

@sunvalleylaw Would say fumey. Don't want to breathe in the mist when spraying. Acid based, don't know but works awesome.

[sunvalleylaw]

@Dacon62 Ok, sounds like acid. And from what I could tell from looking online, it appears that way. And that is fine, as long as you follow up with a sealant after, is what I come away with. Seems like people use StarBrite products, EZ ON EZ OFF, certain toilet bowl cleaners, etc. But they are all some form of acid. And yes, best not to breath it. And I sure don't want to get underneath the boat while applying. A garden sprayer with a wand seems like a good way to go. I am hoping to lift the back of the boat up off the bunks as that is where I need to do it. The rest of the hull is pristine. Then will hit with Griot's poly, which will also act as a sealer. We also have some Nu Finish in the garage I believe.