Advice on Re-Gelcoating Topsides of a 30' hull

[nickhughes]

I purchased an old 30' compass last year that had been sitting neglected in the tropical sun for the last ten years and the gelcoat on the topsides was very chalky and in very poor shape.

As part of a refit I performed an extensive wet sand, cut and polish of the topsides. Unfortunately there were a large number of patches where the gelcoat was wearing through and blue colour was becoming visible so I was unable to be as thorough as I would have liked. I did some small patches with flowcoat and although the colour match was pretty good, 6 months later the there is a marked contrast between the old degraded gelcoat and the new patches.

Given the thin layer of remaining gelcoat I am considering recoating the entire topsides with new gelcoat and would welcome advice from anyone with experience in large gelcoating jobs like this.

In particular:
- Recommended method of application. I have read up on spraying but would prefer to roll or paint on if good results are achievable.
- Surface preparation
- Number of coats, both of standard gelcoat and the final sealing (layer / layers)
- Recommended products/thinners/catalysts to use
- An understanding of how big a job this is likely to be. I am happy to spend a couple of days sanding and then performing another cut and polish but I would prefer it not to take weeks.

Note, I am aware of the one and two part paint options and although they can give good results I am looking for a solution that will last well in a harsh environment.

By the same token I would prefer to steer clear of Duratec as it appears to significantly compromise the gelcoat.

Thanks,

Nick

[mitiempo]

Gelcoat is designed to be sprayed in a mold, taking its smooth surface from the polished surface of the mold.
It is used in touch up but to my knowledge it is not ever used as a whole boat finish like you want.
Gelcoat is not formulated to produce a smooth surface - it doesn't flow like paint.

Paint is the way to go. Interlux Perfection, Awlgrip, or Alexseal.

[SloopJonB]

Actually, re-gelcoating is possible - I have seen it done with beautiful results. A boat refinisher that I spoke to briefly said there were gel products available now that flowed well and did not orange peel badly as they did in the past.

I'm afraid I don't have any specifics but I'm sure you can track them down at any good fiberglass supplier or refinisher.

The first job I saw done this way was a 28ish foot power cruiser. Coincidentally, at the same time in the same yard a 40 foot sailboat was being refinished with Awlgrip. In my opinion the powerboat ended up looking better. The white gelcoat had a pearlescent quality to its gloss - a lower sheen while the Awlgrip had the usual mirror finish.

On the stands the Awlgrip looked better - like a show car but in the water the gelcoat looked better. The mirror finish of the Awlgrip reflected the surface ripples of the water so well that the boats finish looked wavy while the gelcoat looked the same in or out of the water.

[nickhughes]

Hi Sloop,

Yep, this matches my understanding that it is possible and if done right can achieve great durable results.
The key I believe is to minimise 'orangepeeling' otherwise the sanding can turn into a huge job...

Will keep looking for info on how to best achieve this over a large are.

Cheers,

Nick

[eherlihy]

treilley (a sailnet username) had an Ericson 35 that was painted with Imron - and she looked great! If you consider Awlgrip, I would also look at Imron.

[eherlihy]

Here is a pic from treilley's website:


(I hope you don't mind.)

[sailingfool]

Plan to paint the boat, I haven't seen or heard of a boat having new gelcoat applied to the hull in 15 years or more...One reason being that your would need to strip all the existing gelcoat first, an expensive job in itself.

[nickhughes]

Hmm.. the plan was to key the outer layer of the current gelcoat and then add a fresh layer on top (20-30 mils thick), which I would then sand smooth and cut and polish.
Not sure why the current gelcoat need to be totally removed...

[mike dryver]

Hello Nick there is a yard here in Northern Mass. that actually tells you you are better off re-gel coating. it cost about the same as a paint job, but the paint does not usually last more than 10 yrs (I know there are exceptions), where as gel coat that is waxed regularly will last over twice that. our boat comes to mind 32 yrs young and still looking good. hull sides have a high gloss when clean, and i just compounded topsides. we've had boat for 5 yrs and prev. owner wasn't much on maint. so after 5 yrs of trying to revive gelcoat with waxing i gave up and did what should have been done when we bought her. does she look new no, but now i can get to getting a better gloss. you do not have to remove old gel coat as long as it is in decent shape. they do a boat every couple of yrs. yards don't like to do it because not many yards know how to work with product. the other caveat is they do it inside. this is not a big yard a small private owned yard that came from the school of hard knocks, but figuring out how to do it right. no disparagement ment to anyone

[jrd22]

I have had parts of two boats re-gelcoated with excellent results. I did not do it myself though. There is a guy that has been doing fiberglas for a long time in town and he sprayed the new gelcoat over the old and then wet sanded it and it looks like new. We had the wheelhouse sides done on our crab boat and we had the new decks and house sides done on the sailboat. I would recommend finding someone that does it and maybe they can give you some pointers on how to go about it, especially if you are not going to spray it.