Griptex non skid, but in Gelcoat - Not Paint

[Midday Gun]

I've got on upcoming non-skid renewal on my boat that I've been putting off for a couple of years now.

My requirements for a non-skid deck are:
- Good traction
- Durable
- Easy to Clean
- Looks good.

I've spent a bit of time experimenting with panels off the boat using thickened gelcoat & a textured roller, but I haven't had much luck, not only does it not look great, if anyone fell on it they'd probably loose large amounts of skin!

Kiwi-Grip is nice for a month or so, but impossible to keep clean in our muddy estuary, single part paints never last long.

So really its down to either a 2 part poly or gelcoat with non-skid particles added. My thoughts are that Gelcoat should long outlast the paint, so I'm erring that way.
I've bought the Course & Fine griptex particles my plan being to mix them for the final finish. I've seen some photos of griptex in gelcoat decks that look good, but there's not much info on how its done, ratio's etc.

Is it best to do a light coat of gelcoat, wait for it to start getting tacky & broadcast the particles like you might with paint? Followed by a second coat.
Or mix in with gelcoat and roll out, or get a spray gelcoat and spray them mixed instead?

And ratio's, is it the same as paint? Awlgrip recommend 60-75g per 1 litre of paint, is this the same with gelcoat?


I realise that's a lot of questions, hopefully someone has gone through this whole process so I don't have to waste a load of material experimenting.

Cheers

[Chotu]

It’s a little off topic but I went with thickened 2-part polyurethane. It’s exactly like the griptex I remember from when I was younger. On skateboards. Exactly the same. It’s lasted 5 years so far with no change at all.

Just a data point for the thread. I don’t know the answers to how much griptex to mix into the gel coat. I am thinking gelcoat (polyester resin) adhesion might be suspect. What’s the substrate, exactly?

[Midday Gun]

The substrate is gelcoat.
My plan is to sand off the existing worn & discoloured pattern back to smooth gelcoat & then redo.

Adhesion should be fine if the prep is right, I've seen boats that have been re-gelcoated that are fine years later & non skid decks that have been rolled on with thickened gelcoat that hold up way longer than paint ever would.

[Chotu]

Originally Posted by Midday Gun

The substrate is gelcoat.
My plan is to sand of the existing worn & discoloured pattern back to smooth gelcoat & then redo.

Adhesion should be fine if the prep is right, I've seen boats that have been re-gelcoated that are fine years later & non skid decks that have been rolled on with thickened gelcoat that hold up way longer than paint ever would.

Ok. Good!

[s/v Jedi]

Not convinced on gelcoat... it’s too thick! I guess you can thin it?

You don’t want a thick coat with griptex suspended inside that coat... also, you don’t want to cover them with another coat that completely encapsulates it.

I think Awlgrip with Griptex can’t be beat in the tropics. Maybe use SoftSand instead of Griptex but I would use Awlgrip. Also, the 545 epoxy primer will do a great job after sanding down the old gelcoat anti skid.

[tkeithlu]

I'm with the Jedi Master, having used 2-part with grit on one boat, and Kiwi-Grip on another. This sounds much more like a job for sand, prime, paint than for trying to replace the gelcoat. Careful work with one of the modern versions of masking tape could make this job look really good without your fighting with gelcoat.

[s/v michaela]

Why not just use a less aggressive roller for your KiwiGrip.. It is so simple to apply. Anything you put on that has an aggressive surface will get dirty quickly.

[Scubaseas]

Have 3 dive boats that see high traffic and tanks banging around etc. and we use gelcoat with nonskid mixed in every 3 to 5 years on high traffic areas. Low traffic areas are now over 12 years old and fine. You definitely want to mix the particles in the gelcoat and keep gelcoat stirred when applying. Two people works best depending on how hot it is outside. Break it up into small areas, say about 40ft.sq or so until you get a feel of how much open time versus gee it's Jello. Have plenty of extra rollers ready to go and at hand. Prep work is key to good adhesion. 60 grit with surfaced dewaxed and washed BEFORE any sanding is done. Final clean with MEK or Acetone and then a light tack rag. How much particles and what size depends on you. 75g/L sounds about right for medium size nonskid. If you need more pot time ask your supplier to leave out or reduce the amount of Chromium in the gelcoat. Thinning gel coat with acetone can actually make it kick quicker and tends to make it "chalky". How fresh you gelcoat is makes a big difference in how long of a work time you have with it. Fresher being better. Don't forget you need stearate wax unless it's in the gelcoat already (most have it mixed in).

[Cheechako]

I dont see a reason to grind off the old non skid...? With 2 part paint leaving it may work well.
Gel coat worries me as it lumps up a bit and can be brittle. If it doesn't adhere well... will it chip and loosen? But I will say, I had one boat spray gel coated professionally on the cabin + trunk, and it came out well and seemed to last.

Not a huge fan of Kiwi Grip either, although it can be quick and dirty to do. I think you have to just commit to doing it over every couple of years.

[Midday Gun]

Thanks for the suggestions of paint / kiwi-grip, if I go down that route (paint, won't bother with Kiwi-Grip after my last experience) then there's tons of videos & write ups on.

However I want to avoid getting into the paint cycle if at all possible, which is why I'm looking for experience & tips on gelcoat, I've seen photos of it done & boats on which it has been done, but very little info on the process.


@Cheechako, the old non skid was provided by the shape of the surface, this has worn down over 35 years of use & is looking a bit discoloured in places, since the non skid will come from the particles I'm adding, for a uniform finish I want to start from a flat surface.



@Scubaseas, cheers! The boat is only 28 foot, so by the time I've split the side decks, coach roof & cockpit it should be quite manageable. I'll be working in around 12-15 degrees (Celsius) so should have plenty of time.
Do you roll or Spray? (I can get gelcoat that comes already in the correct viscosity for spraying from my supplier)
And how many coats?


(Soft sand rubber isn't available here in the UK without waiting for it to be shipped then getting smashed on VAT @ 20% + import duty + shipping)

[Scubaseas]

Done both roll and spray. Roll is faster (no over spray worries) and much easier cleanup.

[CaptainLen]

We tried Griptex beads with gelcoat a few years ago. It was fine at first but quickly wore away so it lost everything we'd gained. After investigating all non-skid options we settled on Awlgrip (rolled) with soft sand (medium grit). We broadcast the soft sand then sealed with three coats of whisper grey. Three are needed to get the uniform color, so you need the medium grit particles to maintain good non-skid properties after three coats of awl grip. Roll it and spread it well so you apply only a "thin" coat.
We're very happy with the result. Cannot yet attest to durability as we only did it summer of 2019 (in New England) so we're only one summer into it at this time.

[psk125]

We painted with 2-part Interlux poly about 15 years ago and went with Awlgrip this spring. The old paint simply wore off in spots that got a lot of use or chafe. After 15 or so years it was starting to look a bit shabby. We sanded everything down, primed, and topcoated, following Awlgrip's detailed instructions on solvent washing too. We rolled Griptex into our topcoats this time using felt rollers. They hold up MUCH better than any foam roller - several hours, rather than just a batch or two of paint. Despite Awlgrip's cautions about the difficulty of getting uniform coating with a roller, we mixed the Griptex into the paint and found it worked much better than the "sprinkling" we tried the first time. We thought that with the flattening agent we used for the deck and the short-nap felt roller that tipping with a brush on the non-nonskid was not necessary either, though your opinion may differ.
Would think it would be difficult to maintain an even thickness of gelcoat, making it problematic, especially with particles embedded.

[Midday Gun]

So I've attached an example of what I'm after.



The photo is of a J/92s, the decks are original gelcoat, but the non skid is of the particle type rather than the molded pattern style, I don't know if they sprinkled the aggregate into the mold first or if they did it afterwards, but that's the sort of finish I'd like to achieve.

[psk125]

Originally Posted by Midday Gun

So I've attached an example of what I'm after.



The photo is of a J/92s, the decks are original gelcoat, but the non skid is of the particle type rather than the molded pattern style, I don't know if they sprinkled the aggregate into the mold first or if they did it afterwards, but that's the sort of finish I'd like to achieve.

I would use the coarse aggregate then, at the max suggested ratio.