Interior gelcoat with patchy yellow stains

[Rendova]

My boat has a couple off color spots as your photos show. I believe what caused mine was the use of flying bug spray. I am thinking an old can where the contents sputter out. I grabbed a paper towel and some Awesome cleaner and it wiped off easily. I am sure there are other methods to clean these areas.

[walkerwork]

Hi,

I watched a boat restoration video and the boat had the same stain. The person restoring the boat used toilet bowel cleaner for removing rust stains. They started at the bottom of the wall and worked their way up the wall to make sure they did not have streaks of clean and not cleaned areas. Worked great. To clean the ceiling they used paper towels coated in the cleaner to keep the liquid applied longer to the surface. The applied the paper towels like wall paper and kept spraying the paper towel with the liquid, so i would have longer to clean the surface. When they were done everything was white again and it looked great.

Good Luck

David

[frankstar]

You can also try cleaners that are made to delete nicotine stains. They are similar to the stains on your upholstery.

Take a look at:

ProRestore Unsmoke Wall Wash with BioSolv



Krud Kutter KR01



or Savogran 10632 Liquid TSP

[svamnesty]

@fruityloop8

I’m reviving a 3 year old thread to see what you ended up doing (if anything) and what worked. I also have a Bavaria 38 and we have the same patchy yellow stains on the inside.

Before reading this thread, I have tried multiple products to no avail including just yesterday oxalic acid since I had purchased some to remove some rust stains on the outside fiberglass. It worked on the rust stains but had no effect on the inside yellow stains.

I’m inclined to agree with @CF32907 assessment of the issue and am adding painting the white headboard with a 2-part polyurethane paint during our haulout this fall. Unless you found something else to work on your boat since we both have Bavaria’s.

[Captain Puget]

Use a heavy stain blocking primer before painting … 2 coats if the first does not cover the stain up

[Dehler 25]

I have Hunter, but apparently they used the same materials. When I was buying I noticed that some had the discoloration and some didn't, mine didn't but it did discolor the trim around windows. I removed those and painted and they look good two years out.

[svamnesty]

Originally Posted by Captain Puget

Use a heavy stain blocking primer before painting … 2 coats if the first does not cover the stain up

Thanks for the tip!

[svamnesty]

Originally Posted by Dehler 25

I have Hunter, but apparently they used the same materials. When I was buying I noticed that some had the discoloration and some didn't, mine didn't but it did discolor the trim around windows. I removed those and painted and they look good two years out.

Thanks for sharing. Now I know that painting will work!