Polishing

[Stemar]

The topsides and cockpit are grubby after a winter of work and grubby paws (mine), and it isn't washing off easily. What do you use to get your boat clean and shiny?

Nothing with a "Marine Quality, Sir" price tag, please. I haven't got a polisher, just an angle grinder, which I would think too fast for polish, or an cordless drill with a rubber disk and a wool bonnet

 

[Rappey]

I used t-cut and a proper polisher. Was cheap and took all the scratches out of my 4x4.
Would guess you might have to wax it afterwards on a boat.
I used 380 rpm with the bonnet I had. Faster was troublesome for me.

 

[johnalison]

I wash down with gelcoat cleaner, currently International first, occasionally using a Y10-type product if I have been to the Netherlands recently. My white topsides then only need a wax but the HR blue line needs buffing with a cutting compound and polish. The coachroof is treated similarly to the topsides but I now tend to use polish rather than just wax. A few areas that are most exposed, including the stern, need a bit more attention, for which I start with Starbright Colour Restorer Polish, which works well, though I follow it with wax. In all cases I finish with International Wax Sealant which keeps the shine a bit longer and is quick and easy to apply. All except the blue line cutting I do by hand.

 

[oldharry]

For oily fingerprints I found ordinary kitchen cream cleaner works just as well at a fraction of the price of the Marine equivalent. Don't use the gritty type, or you will end up with a matt finish gelcoat! Cream cleaner works a bit like TCut but not so harsh. The clear liquid variants tend not to work so well. Like most cleaners, it will take off the wax coat though, so you will have to repolish afterwards. It has the advantage you can use it in the galley afterwards too! Sparkling hull, sparkling galley all in one bottle!

None of these will work on the yellow staining older hulls get along the waterline though. That needs to be treated chemically with something like Y10.

 

[Concerto]

Any boat cleaner should take off the grime. If the gel coat has degraded, then more action would be required in the form of removing the top surface of the gel coat. How bad and how much you need to do is very subjective. You no doubt have seen my PowerPoint presentation on gel coat repair which has lots of information, only linked again as new boat owners may not have seen it.
https://wiki.westerly-owners.co.uk/images/8/86/Gel_coat_renovation_19May2020.pdf

As to polishing I was recommended by my local glassfibre repair man to use Meguiar's flagship premium marine wax. This is easy to apply and remove by hand. He recommends a minimum of 3 coats.of wax. One bottle should be sufficient for your catamaran as it goes a long way.

 

[ithet]

I used t-cut

I had always thought that T-cut could stain fibreglass? I have no direct evidence so that might just be folk law.