Help with chalk like residue on isinglass

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ragin cajun

Senior Member
Joined
Dec 2, 2014
Messages
350
Location
USA
Vessel Name
presently boatless
I have fiberglass hard tops on fly bridge and sundeck. After a rain or washing of boat a chalk residue streaks down from hard tops on isinglass leaving a rather hard cleaning job after.
What can I do to either seal the hard tops or do I need to just paint the tops. If painting what should I use. Thanks for the help.
 
Greetings,
Mr. rc. Yup, either your gel coat or paint is chalking up. A buff and polish may delay reformation of the chalk layer but ya gotta keep on it. If gel coat, and in good shape other than the chalking you are probably further ahead to wax. If you do repaint, you may run into the same problem down the road.
 
The surface is rather rough on top. I would think compound and wax would not do a proper seal. I wash the tops with woody wax but it doesn't last for very long. I was thinking of a thicker sealing agent for fiberglass might do the trick just not sure of what product.
 
As RTF says, the gelcoat is chalking (a natural phenomenon, it all does it) so you need to protect it from the elements. The typical treatment is to use a mild rubbing compound, color restorer, etc to remove the chalk. Then give the surface a good coat of quality wax.

There are products that purport to seal the gelcoat but anything out in the weather and UV light will eventually sucumb to this kind of deterioration.

It's part of the fun of owning a boat.....
 
Heron, I kinda like your idea but the thought of blotches after a while doesn't seem the way to go. I'll pick a nice weekend and compound away then apply wax as suggested. Maybe I can get a grandkid up there with me for cheap labor!
 
Heron, I kinda like your idea but the thought of blotches after a while doesn't seem the way to go. I'll pick a nice weekend and compound away then apply wax as suggested. Maybe I can get a grandkid up there with me for cheap labor!

I have no idea how long ago this was done...It could have been 10+ years as I don't see any references in the logs I have going back to 2006.. Site says it needs to be refreshed periodically...dunno. I do know it does not come off easily, so likely if done correctly and maintained it might be a viable solution. Like you, I need to try some compounding and waxing before I decide which way to go..
 
Use a sealer like Rejex(my favorite) or Zaino or Starbright Polish with PTEF after proper compounding. Apply properly and those will outlast wax and avoid the blotching or worse Poliglow is infamous for.
 
If it's as bad as you say and has a rough nonskid finish you'd be better off painting it and getting it over with.

Once a flat surface like that that gets lots of sun goes chalky it is hard to bring it back without wet sanding and compounding. And since you said it has a texture to it that will not be possible.
 
Last edited:
Greetings,
Mr. rc. IF you're going to proceed as Mr. 11 suggests do NOT attempt to wax and buff. You will want the surface as wax free as possible for maximum adhesion.
 
Since its the roof, why not put a nonskid coating on. If you repaint you won't want to walk on it if it's remotely wet.
 

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