What to do about old deck finish

[merlin]

I have a 1978 boat which is in generally good shape. I have noticed several patches on the deck and companionway hatches where the surface seems to have pinpricks in, some larger than others. The patches look like they have been there for some time and are the sort of thing that could have been caused by bubbles of some sort of impurity in the original gel coat that have worn across the top to reveal the space below.

A few other parts of the deck, usually corners around the cockpit or near the bow seem to have a darker patch starting to show from underneath which looks like it could be the gelcoat starting to wear thin over the dark fibreglass.

Does anyone know what the best solution is? I would guess painting but have heard that once this has been done once it needs redoing just about every year. Has anyone used any sort of coatings to cover patches of this sort?

Grateful for any advice from those with more experience.

Merlin



<hr width=100% size=1>

 

[JimMcMillan]

You have exactly the same problem as I have and all your surmises are correct.After taking some advice from various quarters I opted for gell coat which is a reasonable price and picked a piece I could remove and work on in heat.Gelcoat even with the additives supplied is hard but 'tacky'and is difficult to rub down to prepare for a further coat. Resin (not epoxy)is as easy to apply and can be rubbed down with dry paper. Both would require overpainting with a good 2 part paint. Pigment can be added to gel coat but is still quite transparent.A whole deck in gelcoat would in my opinion be a nightmare.

<hr width=100% size=1>

 

[merlin]

Oh bugger! Thanks for the info anyway. The boat in question has a light blue deck and as you can imagine after over 20 years the colour has faded to different shades in different places. The manufacterers can't be very precise about the colour and it wouldn't matter anyway since it's all been significantly weathered. Matching the colours will be difficult, there are already several areas where someone in the past has tried. I'll have to think a bit harder about this and count pennies.

<hr width=100% size=1>

 

[oldsaltoz]

G'day Merlin,

The voids you see are common in older boats, it was a problem in the old method of laying up, and the dark area is almost certainly thin gel-coat.

The best cure is not what you want to hear, it means a sanding the whole deck, filling the voids with epoxy resin and Micro-Balloons, sanding off and spaying on some primer; this will show all the nicks, chips and ding you missed, fix them, then apply a good quality 2 pot polyurethane finish.

This will last for many years and look fantastic. I have treated several older boats over the years and they still look great 8 years after they were done.

The worst one was a live-aboard that was not looked after very well at all and had a lot of use, but it still lasted 5 years, and only needed high traffic areas and fitting rubbing points touched up.

I hope this helps and Avagoodweekend.





<hr width=100% size=1> Old Salt Oz /forums/images/icons/cool.gif Growing old is unavoidable. However, growing up is still optional.

 

[Evadne]

I'd agree with this, we had a similar problem. If the voids are there for any length of time water gets between the gelcoat and grp, marine life takes root and causes it to bubble and lift. Scrape the gelcoat off with a 2-handed scraper (sandvik make a good one) and follow the epoxy & microballoons advice. If you're painting with non-slip deck paint then no need to put a gloss coat of 2-pack on first , though.

<hr width=100% size=1>

 

[AndrewB]

I'd agree too. It is true that paint won't last as well as the original gel-coat. The good news though that although its a lot of work the first time, thereaftersanding down and putting on an additional coat of two-part polyurethane every three years or so is comparatively easy. With a little practice a very good looking DIY finish can be achieved, if not quite the show-room gleam of the professional spray job. But that shows more on the hull than the deck.

The main problem, as you suggest, is that two-part polyurethane will give a smooth, slippery and unsafe surface on deck. Deck paint can be used, but is soft and wears quite fast, so in areas of heavy wear I would apply Treadmaster or similar once the new paint is fully cured (at least a month).

<hr width=100% size=1>

 

[merlin]

Thanks very much for the professional sounding advice. As you say, not what I wanted to hear but at least now I know the score and won't waste time mucking about looking for other solutions.

Time soon to sharpen that scraper and get on with it! Luckily we do liveaboard so we have a bit more time - just as well since it sounds like we'll need it!

Regards,

Merlin

<hr width=100% size=1>

 

[merlin]

Good idea - the existing 'non-slip' is a bit glass like after all those years!

<hr width=100% size=1>