Griptex non skid, but in Gelcoat - Not Paint

[Scubaseas]

The bottom left is griptex - course & fine mixed with gelcoat & rolled on, mix of particles was just slightly over awl-grips recommended amount.

Unfortunately the particles aren't super evenly distributed the sheen in the light isn't so nice.

Use short knapp roller and mix really well or add a little griptex to gel, mix and a bit more gel, mix, add more griptex, stir, add more gel, mix etc. etc.

Top right is the distribution method. I've applied a layer of gelcoat & used a shaker to add the griptex. It needs another coat of gel on top of those particles, but I only did them this morning so I'm waiting for the gel to go off.

This method is fine as long as there is no wax in the first coat. If there is and you top coat with finish gelcoat which has wax in it you won't get a good bond between the layers. If you're mixed and catalyzed right you should be dry at about 20 to 35 minutes.

[Midday Gun]

Originally Posted by Scubaseas

Use short knapp roller and mix really well or add a little griptex to gel, mix and a bit more gel, mix, add more griptex, stir, add more gel, mix etc. etc.



This method is fine as long as there is no wax in the first coat. If there is and you top coat with finish gelcoat which has wax in it you won't get a good bond between the layers. If you're mixed and catalyzed right you should be dry at about 20 to 35 minutes.

I used a short nap roller. but maybe too short. It was very well stirred, but I poured it onto the piece & worked out with the roller, maybe I should have used a tray.

I've done it with waxed gelcoat as its all I have, hopefully the adhesion will be adequate for a test panel.

In terms of drying it takes a little longer, I catalysed at 3%, but this is the UK so my garage was only about 8 degrees (c) today, pretty chilly & damp. Plus with the coat being spread out it takes longer, I had other jobs to do so I figured to just leave it till tomorrow morning.

[Scubaseas]

If you can apply the top gel coat while the base coat is still wet or tacky it would work OK. Or spray the top coat it if you have a big enough tip. Don't try putting nonskid through the spray gun though, spray, sprinkle grit, top spray. The wax floats up to the top and keeps air off the gelcoat. Without a wax or other coating (like PVA or even plastic sheet) it will stay tacky. The difference between laminating resin and finish resin is the finish resin includes about 2% to 3% stearate wax. Can't help you with the cure times as I'm used to 34*C to 38*C temps. Part of my annual weight loss program is fixing boats in a Tyvek suit, in the Caribbean in September.


You can thin gel coat up to about 10% with acetone or styrene but it will make it kick quicker and have a bit less gloss. Styrene will tend to yellow it a bit also.


How old is your hardener? MEKP gets tired after about 4 months. 3% should be more than enough. 2% hardener should be ample.


20*C is about the lower limit I'd consider applying gelcoat. 24*C ideal. Anyway to heat the resin and or the substrate? Heat lamp etc?

[Midday Gun]

Temperatures aren't ideal, but it has been hardening, just taking a bit longer.
According to my datasheet I can catalyse up to 4% if required, the MEKP is still good, its no doubt long set, I'll check first thing.

These are just tests to get a feel for what might work and what won't, I'll wait for warmer weather before attempting anything on the boat itself.
I may give the spraying a go, I have an LVLP gun with a 1.8 tip that I use for epoxy primer on car panels, so it may work with a spray gelcoat.

(My supplier does a spray gelcoat, its a little thinner than the standard, but its measured in Poise which means nothing to me. )

[Yachtychuck]

Use LP it will flow better and stay cleaner longer. Gelcoat surface will oxidize fairly quick, and collect dirt.
I mix coarse Griptex stirring frequently and roll with foam roller. I do think a short nap roller would would be more durable.

[Exile]

The youTube channel 'Boatworks Today' has some most helpful videos on the topics discussed. One in particular uses a test panel showing the application of gelcoat and Softsand that would also likely work well with Griptex. A layer of non-waxed/laminating gelcoat is rolled on, and the grit is then applied extremely liberally by hand, covering the entire surface. Once this laminating coat tacks up the excess grit is simply brushed or vacuumed off. The goal here is to get as much grit as possible applied so clumps or gaps are not an issue. At this point a final coat of waxed/finish gelcoat is applied which cures it. There's no need to spray since the final surface is mostly the grit, with the gel simply sealing it all in and for color/tint.

As for using gelcoat vs. LP for nonskid, the consensus seems to be that gel is more durable, so may be the better choice. There's also none of the usual buffing/polishing/maintenance chores since oxidation/chalking isn't much of an issue with the entire surface covered with nonskid. I think gel vs. LP is a much closer call with smooth parts of decks and cabin houses, however, with probably most opting for LP for reasons already discussed. Definitely more prep involved but if you get it right you can probably expect zero maintenance for 10 or more years. The one caveat is it can be a lot harder to fix the inevitable chips and dings. But I've just now completed rolling gel on the smooth parts of my deck and have to say that all the sanding is itself a great argument for using paint instead! Lots of work and, as pointed out, will still need to hit it with my buffer once or twice a year.

Btw, I'm no pro with any of this. Only a DIY boat owner who often finds himself well over his head. Any critiques/comments welcomed and appreciated.

[Midday Gun]

I think I've watched probably every video regarding non skid & gelcoat on youtube, and read every thread here & on the Hull Truth!

I've completed the broadcast with gelcoat method sample, but its raining incessantly & has been for the last 2 days so I need to wait for a window to show it in natural light.

[clockwork orange]

Having been a boatbuilder for decades i have used all the usual suspects and we pretty much use Griptex in one of the Awlgrip paints at work, when it comes to my own boats i like to try new products ( otherwise you never learn anything.) On my current boat the molded nonskid was still excellent as far as grip was concerned it was oxidized and washing off over my new windows so i did a test to see if just sealing it with a coat of awlcraft would be the easy button but it killed the non skid properties so i just scrubbed the nonskid and applied the fine Softsand in Awlcraft with a couple of sealer coats. It was much easier than grinding off the existing non skid and it has proven to be exceptional grip. I used the broadcast method but to be sure it is totally even i completely covered it, like sand on a beach and then vacuumed it off the next day before the sealer coats. You can reuse what you vacuumed up.

[Exile]

Originally Posted by clockwork orange

. . . so i just scrubbed the nonskid and applied the fine Softsand in Awlcraft with a couple of sealer coats. It was much easier than grinding off the existing non skid and it has proven to be exceptional grip. . . .

I was wondering myself whether grinding the original molded nonskid off was really necessary given all the texture you'd be applying on top of it. My original molded nonskid is pretty thin/shallow as it is. So you're saying it wasn't necessary in your case, assuming proper prep is done?

[clockwork orange]

Originally Posted by Exile

I was wondering myself whether grinding the original molded nonskid off was really necessary given all the texture you'd be applying on top of it. My original molded nonskid is pretty thin/shallow as it is. So you're saying it wasn't necessary in your case, assuming proper prep is done?

Correct, think about it, when your gelcoat has oxidize to the point where it comes off when it rains it is perfectly prepped for paint already, you just need to scrub it with a stiff brush, rinse it and let it dry. International paints sells an abrasive liquid for prepping non skid for paint but when its oxidized it has no gloss left to need it. I used the finest Softsand and it is very grippy but it still just looks like the original molded pattern. My son and his girlfriend just finished doing the nonskid on their 42ft cat with medium Softsand and Alexseal and it looks fantastic, they did remove the original because its a custom boat and the old stuff was not molded.

[Uncle Bob]

Originally Posted by Midday Gun

Okay, so I made a test panel yesterday.


Top left is gelcoat thickened with Collidial Silica. Ratio is around 150ml of gelcoat to 5 flat scoops of silica, I used an old kiwi-grip roller. The texture is to put it bluntly, brutal. It might even be safer to fall overboard then land on that!

The bottom left is griptex - course & fine mixed with gelcoat & rolled on, mix of particles was just slightly over awl-grips recommended amount.

Unfortunately the particles aren't super evenly distributed the sheen in the light isn't so nice.

Top right is the distribution method. I've applied a layer of gelcoat & used a shaker to add the griptex. It needs another coat of gel ontop of those particles, but I only did them this morning so I'm waiting for the gel to go off.

Bottom right will be for paint instead of gelcoat, but I haven't made it that far.

The second photo is an old piece of plywood I coated with the remenants of the griptex gelcoat, you can see the uneven distribution of particles. Despite making efforts to stir regularly.



I'm wondering if I bought a spray gelcoat (so much thinner than the standard flowcoat) I could mix the particles in but to a much lesser amount & simply go over the old molded non skid, this might restore the colour and also add traction, while keeping the original 'look'?

Hi, the panel done with the old kiwi grip roller that you describe as brutal, you could try sanding the peaks off and then overcoating with the spray gelcoat. Basically that is the way I have done it but with cork in resin, sanded to reduce the harshness then overcoated with more resin, was a long time ago but it worked and looked the part.

[Exile]

Originally Posted by clockwork orange

Correct, think about it, when your gelcoat has oxidize to the point where it comes off when it rains it is perfectly prepped for paint already, you just need to scrub it with a stiff brush, rinse it and let it dry. International paints sells an abrasive liquid for prepping non skid for paint but when its oxidized it has no gloss left to need it. I used the finest Softsand and it is very grippy but it still just looks like the original molded pattern. My son and his girlfriend just finished doing the nonskid on their 42ft cat with medium Softsand and Alexseal and it looks fantastic, they did remove the original because its a custom boat and the old stuff was not molded.

Thanks for responding, esp. since I'm a bit new to this area of boat refurbishing. From what you describe, my original nonskid is probably in better shape than yours was, although I can't say it was ever glossy. Correct me if I'm wrong, but I gather you're speaking to the adhesion issue, whereas I was thinking more about whether the old molded surface would "print through" the new overcoat if not first sanded smooth. In my case I can't imagine it would with a couple of coats of paint or gelcoat on top of a layer of Softsand or Griptex, etc. But perhaps it would be prudent to sand mine smooth in any event to insure proper adhesion.

[Exile]

Originally Posted by Midday Gun

I think I've watched probably every video regarding non skid & gelcoat on youtube, and read every thread here & on the Hull Truth!

I've completed the broadcast with gelcoat method sample, but its raining incessantly & has been for the last 2 days so I need to wait for a window to show it in natural light.

I'd be most interested in some photos if you're able to post.

[clockwork orange]

Originally Posted by Exile

Thanks for responding, esp. since I'm a bit new to this area of boat refurbishing. From what you describe, my original nonskid is probably in better shape than yours was, although I can't say it was ever glossy. Correct me if I'm wrong, but I gather you're speaking to the adhesion issue, whereas I was thinking more about whether the old molded surface would "print through" the new overcoat if not first sanded smooth. In my case I can't imagine it would with a couple of coats of paint or gelcoat on top of a layer of Softsand or Griptex, etc. But perhaps it would be prudent to sand mine smooth in any event to insure proper adhesion.

I think we may have different goals, in my case the molded nonskid was not worn away at all and was performing its job just fine, probably better than when it was new, the only issue being the oxidization where every time it rained white powder would wash down from the cabin top over the new windows. I was not looking to prevent the original non skid from printing through, ie, not trying to hide the pattern, just trying to freshen it up as i had just repainted the smooths as well as seal the oxidation without losing the non skid properties. I first did a test on the anchor locker lid just sealing it with Awlcraft but that made it too slick so the alternatives were to grind all the molded non skid off and start afresh which i felt was a lot of uneccesary effort for no gain so i just scrubbed the existing non skid with a stiff nylon brush an a bit of soft scrub and plenty of running water. Most people seem to use the medium Softsand but i chose to use the fine as i already had functional non skid. It is excellent and you only notice it if you are up close, The original non skid pattern dominates visually which is what i was after. If you are trying to hide the old non skid you need to remove it, its a lot of nasty work. On a different note, regardless of what you are using for grit coarser does not mean less slippery. We just got done with winter haulout and I was involved in taking down the rig of an Olson 40 which we had painted, including the non skid a number of years ago, all Awlgrip products and the non skid was done with coarse Griptex because these boats have a lot of deck camber and a few of the guys from the shop have raced on the boat and bitched about the non skid drawing blood and wearing out clothing and yet its not that grippy, certainly not as good as the fine Softsand/Awlcraft i used. I think I would have used medium if i was starting from scratch though and that's what my son and his girlfriend used on their cat and it looks great.

[Exile]

OK, understood. And thanks for taking the time to reply. Also interesting about the non-slip characteristics of the different grits. I was inclined towards the finer ones based mainly on personal aesthetics, so good to know they also provide plenty of grip. Fwiw, and based on videos I've seen, it looks like Griptex is quite a bit finer overall than Softsand, with the coarse Griptex actually looking quite a bit finer than the medium Softsand.