Interior gelcoat with patchy yellow stains

[fruityloop8]

Hi,
Firstly - first post of many to come from me!

I am about to put an offer in for a Bavaria 38, boat is in great condition except for one thing... the headliner (in this boat not fabric, just the glass & gelcoat in white) has ugly yellow patches all over the interior.

Current owner doesn't know what it is, was like that when he bought it. The original owner was a live aboard and heavy smoker (boat doesn't smell like an ashtray), so it could be that. Current owner has tried to clean (don't know with what) with no success.

Anyone have any ideas what it may be?

And I guess my 2 options would be:
1. Try bleach / gelcoat white cleaner products
2. Repaint in white. I'm not against doing this, but the headliner has a textured pattern to it. If I have to sand back the gelcoat for the primer/paint, I run the risk of making the texture somewhat distorted and ugly...

Many thanks for the help!
Cheers

[zemurray]

Is that a separate headliner that comes out, or is it the actual fiberglass cabin top? Is it possible that core has gotten wet and stained through the gel coat?

It sort of looks like some adhesive was used in the past to glue something on. I would try a couple of solvents to see if it does any good. I’ve used acetone to clean varnish stains off gel coat and it worked. Be very careful and test a small area first. There was also a recent article in practice sailor regarding the best solvents to use for various boat clean up jobs. Give it a look.

[coopec43]

I have no idea but have you considered oxalic acid?


https://www.doityourself.com/stry/4-...or-oxalic-acid


https://hurricleanlouisville.com/rus...louisville-ky/

[fruityloop8]

Thanks for the response. Its the fibreglass cabin top so not removable. I hadn't thought about that, I would be surprised if it was wet core because the exterior of the cabin top is in great condition, and this staining is all over the interior of the boat (would be a very soggy core). But curious if other people think the same, maybe it would need need a deeper look!

Can adhesive absorb into the gel coat? I felt the stains with my hands and there was nothing external to the surface, or sticky residue...

[fruityloop8]

Originally Posted by coopec43

I have no idea but have you considered oxalic acid?


https://www.doityourself.com/stry/4-...or-oxalic-acid


https://hurricleanlouisville.com/rus...louisville-ky/

Thanks, Oxalic would be one of my attempts when I can get my hands on the boat! Just not sure how big of a job im up for...

[Uncle Bob]

Originally Posted by fruityloop8

Thanks, Oxalic would be one of my attempts when I can get my hands on the boat! Just not sure how big of a job im up for...

Huge job, will take days of labour, ..............Now about that price you wanted for the boat......
Use the defect to your advantage.

[coopec43]

Originally Posted by Uncle Bob

Huge job, will take days of labour, ..............Now about that price you wanted for the boat......
Use the defect to your advantage.

OMG How embarrassing!


Fruitiloop not all Australians have Uncle Bob's attitude: It's just the Sydney-ites We in the West call them ESBs

[UFO]

Always had great results for surface based stains with Grunt - Phosphoric acid based i think


https://www.whitworths.com.au/grunt-...-remover-500ml

[Uncle Bob]

Originally Posted by coopec43

OMG How embarrassing!


Fruitiloop not all Australians have Uncle Bob's attitude: It's just the Sydney-ites We in the West call them ESBs

Why thank you coop, it appears that a humorous lighthearted suggestion that the OP use this as a bargaining point has gone straight over your head, here's hoping that Fruitiloop is a little more perceptive.

[fruityloop8]

Thanks for all the comments.

Bob - yes I already discussed with the owner that this is something I would need to fix so will take it into account of my offer.

Some good suggestions of products to try. Is anyone familiar with what the stain may be? Anyone bought a boat from a heavy smoker previously?

[boatbroke]

Hi Fruityloop8,

Most probably just mould!

Being fibreglass can it should wipe off with a damp rag, bleach or the acids as previously mentioned. A weak HCL can often work.

Trouble with all the acids upside down making a mess, maybe try a bit of cutting polish by hand may work.

Betting it will come off easy as no matter what you try with it.

Good luck!

[Uncle Bob]

Originally Posted by fruityloop8

Thanks for all the comments.

Bob - yes I already discussed with the owner that this is something I would need to fix so will take it into account of my offer.

Some good suggestions of products to try. Is anyone familiar with what the stain may be? Anyone bought a boat from a heavy smoker previously?

[Pete7]

We have a similar patch about the size of a dinner plate on our ceiling. However, it is vinyl on ply boarding. No ordinary cleaning materials will remove it and I suspect anything really strong will "bleach the patch" and leave the rest looking odd. We think the paraffin lamp we found on board when we bought her 12 years ago was the culprit.

Any chance of getting back on board with some wet wipes, wet cloth with bleach and finally a dab of Oxalic to see what happens? If it comes off and would mean a days work scrubbing so that's one thing. If nothing touches it, then its a problem and whilst probably cosmetic you will constantly notice it, so I would want a few $$$ off the price as would anyone else buying it.

Pete

[Trwl36]

Hi,

Before you do anything drastic, try bleach/cleaner. It looks from the streaks in the stains that someone tried to clean it off ineffectively.

I once bought a house that had a den I thought was painted with a ugly peach color. Turned out that the walls were coated with cigarette smoke by products, underneath was an off white paint.

[Howler]

Originally Posted by fruityloop8

Thanks for all the comments.

Bob - yes I already discussed with the owner that this is something I would need to fix so will take it into account of my offer.

Some good suggestions of products to try. Is anyone familiar with what the stain may be? Anyone bought a boat from a heavy smoker previously?

Some inverse logic... my previous boat had similar stains but I know the prior owners were NOT smokers. So while it doesn’t rule out smoke, it suggests other causes may be possible. Also, I would guess smoke stains would be more uniformly spread whereas your photos suggest very localized stains.