GelCoat Yellowing

[TrenchFisherman]

So I have a 2006 Pro-Line 21 sport that I bought brand new a few years back. I take extremely good care of the boat with waxing twice a year and cleaning it after every trip but this year i started noticing yellowing on the gunwales. Its only on one edge and it spans approximately halfway across. It seems to be like a straight line. I called pro line and they said its probably some kind of wax of lubricant they used on the mold that is seeping to the surface so i should just use some fine grit sand paper and rub it out. Does this happen often and should i really be sanding my semi newer boat this early? Is this a manufacturers defect? Thanks in advance guys!

 

[crazy charlie]

Re: GelCoat Yellowing

The first thing I would do is use either FSR (fiberglass stain remover) comes in a blue gel in a jar $15 or some on-off Marykate also about $15 or some liquid or gel toilet bowl cleaner $1.Any of these will get out an organic hull stain.If this does not work then I would try a rubbig or polishing compound before something like wet sanding.It would be highly unlikley to need something that aggressive.Charlie

 

[ondarvr]

Re: GelCoat Yellowing

It's not wax or anything like that, the main cause of a yellowing radius is thick gel coat, or I should say thicker than the surrounding area.

Thick gel coat will yellow faster than thin gel coat, this is due to more styrene and base resin being near the mold surface, these are the products in gel coat that turn yellow.
This is very common and can be found on many boats if you look for it. Over the years as the gel coat begins to chalk this layer sluffs off and when the boats get buffed and waxed it looks good again.

Typically when the boat is newer this yellowed layer will be too thick to remove with a buffer, but try that method first. The normal solution is to wet sand with fine paper first, then buff.

 

[TheWoodCrafter]

Re: GelCoat Yellowing

I am still amazed at the wealth of knowledge on this forum.

A great explanation. Thanks for sharing.