Non Skid Aluminum Deck, epoxy/grip best options?

Hey,

new to the forum, happy to be here

Admiral Shellfish Company has a top water aquaculture farm on Fort Morgan, AL peninsula. As we expand our site deeper, we need a large sq foot area out at sea. I have two fiberglass pontoons with motor mounts on them. There are cross members across the span, and I have aluminum tread plate coming (5052-H32 TRD PLT .125" thick) and want to make a non slip coating and protect it

Ive seen duragrip, and adding extra grip. as well as epoxy and sand, but wondering exactly what epoxy. and Im curious if interprotect 2000e would be helpful to protect it but it is so pricey. Any advice would be appreciated!

 

Welcome to the Forum Admiral.

Re your two fibreglass pontoons, are you going to effectively create a catamaran hull form with them?
If so, what are the dimensions of the pontoons, and what will be the overall width of the catamaran that will be built?

Have you actually ordered the 1/8" thick treadplate already?
If you haven't, then in view of how you are going to paint it with non skid anyway, then you could perhaps just use 'ordinary' marine grade plate, rather than tread plate?
Bear in mind that it is 'only' 3 mm / 1/8" thick, and that it will need quite a lot of support underneath. What will the stiffener spacing underneath be?
Re painting aluminium with non skid, we have found that a 2 pack paint with sand works well, and is relatively cheap.

 

Thanks Bajan!

Yes all is ordered or onsite. it will be a catamaran, 28'X10' in the end. can displace like 12,000 pounds.

yea I as worried about the thickness, after talking to the aluminum fab who had some experience we settled on this size. under the deck, there will be C-channel that is a bit over a 2 inch on the topside, space every linear foot. so there is a ten inch span, 2 inches support, 10 inch span. with a 3 spots reinforced where we are going to put some components like cleats davits etc.

The "2 pack paint with sand works well, and is relatively cheap." sounds great. where can you get that? have a specific product in mind ?

 

Why would you want to paint anything? Tread plate is naturally non skid, that's what it's designed for, it does not need additional non skid. No paint will stick long on those diamonds anyway, to many sharp corners.
Aluminum has its own corrosion protection, just order the right alloy. If you want paint (for the smooth parts only), use a paint system specifically designed for Al, without the right primer it's not going to stick.

 

agree it provides some. At first it wasn’t going to at all. However there is a ton of mud, algae, fouling growth from gear and various other slippery things around, and lot of water of course. I want to add something extra for safety especially when carrying things etc

 

I concur with Rumars here, almost all of our workboats have had bare tread plate working decks. Two things to improve though; first your deck should have a slight radius, it clears the surface from water, and second: take a grinder with a coarse disc and just "roughen" the top surface of the diamonds. Do NOT cover the alu surface with anything!

 

I've covered entire pontoon boat decks with diamond plate, plus large section of several jet boats.

None of these needed any additional treatment to be more skid resistant. If oil or fuel is spilled it may become a bit slippery though.

Some plate comes with a polished finish, this can be a bit slippery at first, but it scuffs up quickly with traffic. Using mechanical abrasion will speed up the process and give high spots more grip.

 

Herculiner

 

I have had experience of bare aluminium treadplate decks, and also aluminium decks (no treadplate) painted with non skid, and I must admit that I do prefer the latter.
The ally deck on the cat in my avatar photo is simply painted with sand for non skid (on top of suitable primers) - it is now 21 years old, and I think it has been repainted a couple of times since it was built.
But this has been in the tropics, where there are bare feet on a wet deck, and the ally treadplate is definitely more slippery then.
I have been on unpainted treadplate decks with boots on, and they have been fine (although I would still prefer a painted non skid deck).
I note that Admiral is in Alabama, on the Gulf of Mexico, and I presume that summer temps can get pretty hot there.
If you have strict rules re PPE on your aquaculture farm, such as wearing boots even in hot weather, then you should be ok.

Admiral, re the photo in post#3, I think you mention that the channels have 2" wide flanges (but I am not sure) - if this is so, then it looks like they could be 4" x 2" channels? (Or maybe 6" x 2" at the most?)
How are they attached to the decks (fibreglass?) of the hulls?
If they are only 4" (or even 6") deep, I would be a tad concerned about the structure racking (twisting) while underway, especially when heavily laden, and if the sea is not calm.
Re the displacement of 12,000 lbs, is this the intended maximum design displacement when loaded?
Have you calculated the buoyancy available with these hulls at different drafts?
Do you have an estimate of the weight of the completed hulls without any cargo on them?
And what size O/B engines will you be installing on the pontoons?

 

I agree with both Baeckmo and Bajansailor.

But as Bj notes, we have similar experiences.
The tread plate is great stuff, but if constantly exposed to water, and if you don't have the correct footware, it can get/feel bit slippery. Hence sand painting them..
So it really depends how exposed the deck will be and as Bk notes, adding camber will help to mitigate this.

 

Thank you all for the advice an experience this forum is great, a lot of knowledge.
Yes PPE is a must boots etc .

the C channel is 4"X2". They are bolted to the aluminum lip on the pontoons (significant reinforced laminated on the lips) in 4 place. I am also worried about twisting and sea worthiness. This is a calm weather boat but like any captain knows you get stuck where you dont want to be sometimes.

With pontoons, deck, two 70-90HP four strokes, steering console, cleats, davit, racks for storage, and safety railing: something like 6,000 pounds. And add gear and men for working condition, add 1,500lb max.

I do not know how to do the buoyancy calculations but would be happy to try, i have the dimensions. Shipyard reports 18" draft at 15,000 pounds.
they are used for houseboats, and supposedly get decade out of them. For most of the year we are in the lee shore, and have a harbor yards away for weather. So the plan is calm weather work