Re-Gelcoating Non-Skid & Deck Areas

Discussion in 'Fiberglass and Composite Boat Building' started by Midday Gun, Mar 21, 2019.

  1. Midday Gun
    Joined: Mar 2019
    Posts: 55
    Likes: 7, Points: 8
    Location: UK

    Midday Gun Junior Member

    Good afternoon.

    I'm looking to get some advice around renewing the gelcoat on the non skid of my deck also on the non skid areas around the cockpit / coaming etc.

    I've spent hours reading threads but I would still like some advice on the ways to go about this.

    She's an MGC 27 (sailing) built 1986.

    So really its a two prong question, I need advice with the non-skid areas and for the gloss coaming areas etc.

    Starting with the non-skid, a previous owner has done the non skid once before, and I believe that he used some sort of gelcoat / flowcoat with non skid particles added. (I've attached some photos) This has held up reasonably well, although its getting thin in places and I'm seeing some slight bleed through of the original colour, especially when the deck is wet.

    However I've removed some old deck hardware, filled some holes etc, so really to do the job properly I'd rather renew the lot. I can match the non skid pattern by taking a mould off the existing non-skid and using thickened gelcoat, which I'm happy with, but regarding covering the rest of the non skid, what's the best method?

    Add some non skid particles & roll it on? As its going over the top of the old pattern does it need thickening?

    Regarding the glossy areas, the old gelcoat was never particularly good, its worn almost through in places & has a lot of pin holding and crazing. (see photos)
    I've filled some hole from old instruments, removed deck hardware etc, the white gelcoat I've used to finish these repairs is way off in terms of a colour match. Plus the old gelcoat is so gone it simply won't buff back anymore.

    There seem to be all sorts of methods I'm reading about out there, but my tenative plan is to:
    - Sand with 80 grit.
    - Widen and fill crazing cracks
    - Making sure everything is filled & faired.
    - 3 coats gelcoat. The last one with a wax additive
    - Hours of work wetsanding & polishing

    Can I roll & tip the gelcoat? I'm not adverse to spraying, but I would have to go and buy the equipment for it.

    Any advice on how to go about this much appreciated.

    And please if your advice is to paint it, I realise that paint would probably be easier, and I've done it on previous boats. But this time around I want to avoid that and keep it gelcoat. I'm prepared to put in the extra work.

    Current gelcoat condition in cockpit. (Prior to reglassing holes)
    [​IMG]
    [​IMG]

    Current Non-Skid Photos:

    [​IMG]
    [​IMG]

    [​IMG]
     
    Last edited: Mar 21, 2019
  2. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    Welcome to the forum.

    Lots of non-skid techniques. Some easily done others not so.

    I have rolled many hundreds of gallons of gelcoat. My local air quality control board forbids spraying it. Rolling adds considerably more time and effort to the wet sanding and polishing phases. You won't sufficiently develop the tipping off skill in this project. I strongly suggest rolling three coats of gelcoat onto a full 4x8 sheet of plywood, sanding it smooth and polishing it before starting on your boat. Then decide if investing in spray equipment is warranted. If you do decide to spray, please use your 4x8 test panel. This panel is also useful to test non-skid techniques. It is not unreasonable for a newbie to use more material in testing and practicing than on the real project. Also, practice masking off boundaries for non-skid.

    I am alarmed by the adhesion failure of previous coating. It will continue to fail, causing your coats to come off with it. The only way to guarantee 100% adhesion of your new gelcoat is to remove 100% of the previous, exposing 100% of the original surface.

    Good luck
     
  3. Midday Gun
    Joined: Mar 2019
    Posts: 55
    Likes: 7, Points: 8
    Location: UK

    Midday Gun Junior Member

    Thanks for the advice. Definely a good idea to practice on some scrap first.
    I did try buying a premixed gelcoat nonskid, but I tried a test piece first and you could probably file a piece of metal with it as its so harsh.

    Regarding the adhesion failure, its only failed where he's gone over formally glossy areas with it and probably not keyed it correctly. Fortunately those areas are easy enough to sand back.

    Do you think unthickned gelcoat with say griptex added would work, rolled over the existing pattern, providing the surface was adequately keyed say using a fibre or wire wheel and then washed down with acetone?
     
  4. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    Are you 100% sure he thourally keyed 100% of the rest of the boat? That there is not another
    With enough coats, yes. The roughness of the existing non-skid will determine how thick the over coat needs to be. The rougher the non-skid the thicker the over coat. Sanding the surface smooth or thickening the coating will reduce the number of coats required.
     
  5. Midday Gun
    Joined: Mar 2019
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    Location: UK

    Midday Gun Junior Member

    It seems to have adhered well to the existing non-skid. The only areas it hasn't have been where a self tacking track was removed. As well as the shiny gelcoat, its possible that there was silicone or some other form of sealant still on from when the self tacker was present.

    I guess the trick is adding enough to make it work, but not so much that all the gaps are filled in? (between the non-skid pattern)

    Finally, masking, does it need come off between every coat before it sets, or can I leave it till the final coat?
     
  6. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    I usually plan on a whole new non-skid. Gelcoat should be applied over ten times thicker than typical paints. This usually obliterates at least some of the previous non-skid.

    Any masking is left inplace when the gelcoat cures will be extremely difficult to remove. I keep any masking paper or film about 1cm from the critical edge. This can often remain in place for much of the process. The final cm is covered by tape which I remove and change with each coat. Occasionally, I will lay several layers before starting to gelcoat. I can then remove them one layer at a time with out risking smudging soft gelcoat.

    I don't mean to imply that you can't over coat the previous work. Only wish to state the dangers of doing so. If you are comfortable with the existing adhesion, then by all means carry on.
     
  7. Midday Gun
    Joined: Mar 2019
    Posts: 55
    Likes: 7, Points: 8
    Location: UK

    Midday Gun Junior Member

    Thanks for the help.

    I'm currently experimenting off the boat with bits of plywood and a couple of non important boat bits to see what actually works.
     
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  8. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    It is great to hear that you are actually practicing. Most people want to immediately jump into their project. Then are disappointed with the results.

    Please keep us posted as you make progress.
     
    Midday Gun likes this.
  9. Midday Gun
    Joined: Mar 2019
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    Location: UK

    Midday Gun Junior Member

    Well I've completed the coach roof, overall I'm quite happy however one thing that didn't show up on the smaller sample pieces was the glossiness of the gelcoat. The reflection from the deck is a little on the bright side. Can I add something to the gelcoat (talc?) to try and reduce the gloss a little bit without compromising the gelcoat itself?
     
  10. Zippydoodah
    Joined: Jun 2019
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    Location: Christopher, IL

    Zippydoodah Junior Member

    Just saw your thread. Looks like the non skid was added on aftermarket. Peeling because it wasnt sanded good enough. Have you repaired it? If ya havent heres what I would do. We used to take "star board" and make a wedge out a it. And hit all questionable parts. Looking for cracks and what not. Even scraping it against the no skid. Router bit all around the edge so its angles a bit. Even if you get into the gelcoat below or glass, it's ok. Not taking too much off tho. Flat areas we dabbed the catalyzed gelcoat in to fill up the area completely, even humping up a lil bit is what ya reall want because gelcoat shrinks as it dries. When your done doin that let it cure completely. Naturally, dont use a heat gun or anything on it.
    After its curved, wipe sthe stickiness away with acetone.
    Check to see how much it shrank and sand flat accordingly with 400. Keep the sander flat and concentrate on the repaired area. Going into the other non skid is ok. Not too much tho. Now wipe clean with acetone. Get some catalyzed gelcoat and a bit of cheese cloth. Dab the cloth in the gelcoat, then dab on repaired area. Dab until it looks close to matching. Dont worry if you have high points, like from lifting up the cheese cloth and the gelcot pulls with it cause the ne thing you will do it hit it lightly to get rid of all those after you DAB acetone one it again to become the stickiness. HANDSAND lightly to make it.like the original. Lightly buck tofinish. If you want to fix those side pieces, lemme know. I've built over 100,000 boats in my career. If ya already did the repairs , can I see them? Thanks and Be Safe
     
  11. Midday Gun
    Joined: Mar 2019
    Posts: 55
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    Location: UK

    Midday Gun Junior Member

    I did one coat of rolled flow coat with the international non skid additive added. It seems to match what was on previously, however I found it a bit too glossy for my liking which I didn't pick up on the test piece.

    Since then I've decided to fix some bits of core so I'm probably going to redo the whole lot again. This time I'll do some experiments with thickned gelcoat laid on with a notched trowel and then rolled over.
    I've got an old Kiwi Grip roller so I'll try that first (hopefully it doesn't melt from the solvent) and I'll get a selection of other rollers to try.

    I'll put it on uncatalysed to experiment with the texures I can achieve.
     
  12. Blueknarr
    Joined: Aug 2017
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    Blueknarr Senior Member

    One problem. Catalyzed doesn't behave the same as uncatalyzed.
    It is more of a timing thing. Early and it lays back down. Late and it won't lift into peaks. Time it right and perfect peaks.
     

  13. Midday Gun
    Joined: Mar 2019
    Posts: 55
    Likes: 7, Points: 8
    Location: UK

    Midday Gun Junior Member

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