Marine Ply Seal or Not?

[Screamin Semen]

I am replacing the floor in my 5.3m Ally C/C using 12mm marine ply for the job (got it cheap)....I have been reading alot of mixed reports on if you need to seal it or not :-? So my questions are:

Do I have to seal it?

If so then what product (name) should I be using?

I will be using sikaflex to glue carpet down

Thanks in advance ;)

[Dan5]

Definatly seal it with an exterior/marine sealer......everdure is good.....or monocel.
and i'd use contact adheasive over normal sika....something like parfix or sellys quick grip contact adheasive.

Marine ply has more laminates than structual so more lamenents means more glue but it still has to be protected.....marine ply alone untreated will rot.

Dan

[Screamin Semen]

Cheers for the reply Dan...

So I would need to buy the primer and activator and mix 1:1 ratio?

Would I need 500ml or 1L of each to do the trick on two 2400 X 1200 sheets both sides?

Cheers ;)

[sleepygreg]

Make sure you seal the edges....this is the critical area in ply...even marine ply. The difference between marine ply and other plys is that marine ply has no core gaps. They use tha same glue as the other ASA std CD,DD, and formplys. You must seal the edges...as its the timber that rots not the glue.

Greg

[rogerb]

I'm with Dan5 and sleepy greg. Definitely seal both sides and the edges, leave it untreated and it will rot.

Rog

[Dan5]

Cheers for the reply Dan...

So I would need to buy the primer and activator and mix 1:1 ratio?

Would I need 500ml or 1L of each to do the trick on two 2400 X 1200 sheets both sides?

Cheers ;)

No mate they are a 1 pot mix..(everdure....bondall monocel)....thin it down a bit for the first coat and it will penetrate right in then apply another 2 coats.......

Just buy 4lltrs from nubbings for around $70 of either.....should be heaps then.

Dan

[Screamin Semen]

Cheers Dan....these 2 products is what confused me....1 says primer and 1 said activator

https://www.whitworths.com.au/main_itemdetail.asp?item=60657&search123=everdure&intAbsolutePage=1

https://www.whitworths.com.au/main_itemdetail.asp?item=60616&search123=everdure&intAbsolutePage=1

I will try bunnings for a cheaper price :)

[Rhinoc]

Don't forget if you drill holes in the ply to fix it to the floor frames you will also need to seal these otherwise water will penetrate. Last time I did this on my old boat I used one of those syringe type things that come with the kids medicine and squirt the product into the holes after they're all pre-drilled. Let the product soak in and dry before fixing the floor down to the framework.

Definitely use contact adhesive to glue the carpet to the ply. I've got a compressor and spray gun that I used to spray both surfaces and let the glue go tacky/dry before gluing down. Ensure you overlap the side 50 to 100mm round the edges so the carpet wraps to the underside.

Rhino...

[deckie]

Cant sleep, too bloody hot n humid in Syd tonight. No idea how u sleep in nth qld this time of yr. Anyway maybe this will put me back to sleep.

The marine ply advantage/debate will go on forever but the thing to remember these days is the huge amount of crappy supposedly marine ply coming in from places like indonesia. Marine ply aint marine ply anymore coz u cant trust its heritage. The price differences are huge and i doubt there;s much trailerboatie advantage in it unless its the truly good stuff. There are varying grades of it and realistically if its low grade marine ply you may as well save money and get some decent CD ply which has the same waterproof glues as far as i know. Probably more a money making venture to call some of the stuff 'marine" ply making people think they're getting top shelf stuff ply. When u consider u need to seal any type to be used as decking, the cost savings can buy you the stuff to seal it..might even pay for a bit of carpet too if doing a full deck http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/Original%20Smilies/cool.gif.

Anyway...first thing i reckon is you're on absolute bare minimum with 12mm as decking. Been a lot of ply decking go down and great composite alternatives these days, but ply still lasts great IF SEALED PROPERLY and 15mm has been found the go/norm for a real solid feel underfoot...especially if a fair way between floor joists. But sounds like u got a good price on the 12mm so go with it she'll be fine. Saves a bit of weight/fuel anyway http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/Original%20Smilies/cool.gif.

Various ways to prep for a deck and stuff to use. All about $ and time and your choice how u go. As mentioned by Dan Greg and Rog its truly all about the edges if u want it to last. Plus of course the holes for fastenings being sealed well as u put it in.

Heaps of ways to go for sealing but if u want it to last u must do it. Especially knowing 12mm will flex a bit more i;d be making absolute sure the first coat of anything soaks into the ply..or maybe even 2 thin coats soaks in especially at edges. Even good epoxy will crack thru under constant flexing and then its not exactly the w/proofing u had in mind for the $..if the stuff has an initial coat underneath thats really sucked into the ply it makes common sense you'll be fine long term. So basically i;d be either slightly thinning down whatever u use for a first coat or use an already thinned product like everdure which is pretty much just thin epoxy and been around forever under different names. Works.

In terms of what to use to seal it there's lots but some things are proven. Dont use things like bondcrete, varnish or enamel paint type stuff no matter what people say...it can actually work out more expensive anyway for less quality sealing.

Everdure is still great stuff but they charge like a wounded bull for it...its a great consistency for ply coz fairly thin and soaks in for the first layer or two, but beware to do a job that'll last you need multiple coats and it takes a bit more time to cure ...all adds time...and beware something the size of a deck needing a few layers can be expensive...the top option though esp for thinner ply and esp if u havent worked with evil epoxy resins n stuff much before. Wear protection for breathing and skin. For something like decking you'd be looking at bare minimum 2 on flat parts but more like 3-4 coats on edges and as long as u measured up fine (and allowed for the carpet..do a trial fit before sealing the ply) it'll last longer than you. Whilst we know epoxy is definitely far more w/proof than poly resin, if u glass the upper side using cheaper poly resin and light cloth i'd be surprised if the pendulum didnt swing the other way and it was MORE w/proof. Take about the same time and less $ too...just round the edges off a bit and take the cloth around and under. I'd suspect its an even better way to go for 12mm as decking especially if a fair way between supports. Very easy to do even if u've never glassed anything before.

An alternative a bit cheaper (not quite as good as epoxy of course but still better than 95% of things about) and just as importantly FAST...is to wander down and get some polyester resin which is far cheaper. At a place like FGI u just ask for something called "styrene monomer" as well which u will use to thin it a fraction and is cheap as chips. (Dont use acetone to thin resin more than about 5-10% coz it weakens it). They'll give u some catalyst which u simply use a disposable syringe to pop about 1.5% by volume into a normal resin. Just mix roughly 30% styrene monomer to 70% poly resin (dont need to be accurate except with the catalyst) and take the catalyst up to about 2-3%...u get a nice thin mix and just slap it on with disposable brushes and old ice cream containers. make sure its all coated but get right into the edges. You can try to clean decent brushes with acetone or just throw away $2 disposables as u go..works out about the same $. This time of yr will only take about 20-30 mins to start to cure and good to whack on another coat almost immediately within an hr. Add a second coat all over thats got a bit less "thinner" in it. Then just do the edges with a final 100% resin (roughly 1.5% catalyst) and it'll last. NOT as good as epoxy but this WILL last very well and save $. Great base for flowcoating but also for carpet...just run your palm over the surface and sand off any spikey bits or lumps that will wear up thru carpet. Its FAST too, dries very fast this time of year (sometimes way too fast) and ready to get on with the carpet. BTW round off and tidy up the edges of the ply a bit slapping it on. You should notice the first coat especially soak the hell right in..its the porous edges u kinda want to fill up with the stuff.

If you're laying carpet i;d go with the other guys and use some sort of contact adhesive rather than the evil white gunk..which will just end up in your hair, up ya nose and even find its way onto the lounge room carpet somehow http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/Original%20Smilies/grin.gif. That kwik grip tis good and bostik make a contact bond that sticks like shit to a blanket just follow directions. In many ways u dont want to use too much coz u may want to get the carpet off one day so go easy. There are flooring adhesives u can get as well that might be cheaper to roll on and just as good...they use it to lay outdoor caprepts and astroturf type stuff. Just remember to seal well any holes u drill for fastenings which is where that evil white gunk really comes to the party.

Sorry if a ramble... probably repeated myself a dozen times..back to sleep with me.

[Screamin Semen]

Deckie mate thanks for your post, very good read..I think I will fork out the dollars and get a big tub of everdure and do 3-4 coats as I would like it to last. Few questions:

After pre drilling the holes for the screws would dipping each screw in the everdure before screwing them in be good enough?

Roughly how long between the everdure coats? 24h?

How bad is this stuff? Will a proper mask be required or just big open space and some gloves?

Cheers.

[deckie]

Nahhh nowhere near that coz from memory with the everdure you need to apply each coat when the previous one is still a bit tacky to get it to work right. Havent used it for awhile but i;ve got some in the garage so ill check. The poly resin solution isnt really much quicker to apply i guess but full cure this time of yr is damn quick if you're in a hurry.
Might as well stay up now but gimme a hr or so coz there are these dirty great big spiders that have been weaving webs between me and the garage lately and scare the shit outta me...went thru a web a week ago and spent an hr brushing off imaginary spiders. Gimme the eebie jeebies..big girl yeah i know. Sun will be up soon :D Might be time for bacon and eggs anyway;D.

The stuff aint cheap so beware. I'd say u could easy do 3 coats during the day no trouble but i'll check the label. Like all epoxies they have a shelf life too so the stuff i've got leftover is probably already half useless...i wouldnt buy extra thinking it'll be handy one day.
I'd just soak a bit of it into each hole ...i.e. fill the holes and let it cure a bit then screw in...alternatively just use sika in the hole and on the screw then whack in.

The stuff smells like u definitely NEED a mask and gloves..being epoxy u would anyway. Gimme a bit and i;ll check the label and be back.

[maimai]

Make sure you seal the edges....this is the critical area in ply...even marine ply. The difference between marine ply and other plys is that marine ply has no core gaps. They use tha same glue as the other ASA std CD,DD, and formplys. You must seal the edges...as its the timber that rots not the glue.

Greg
No. the glue is not the same

Cut and past from a woodwork forum



From Professor Gene Wengert, Sawing and Drying forum technical advisor



There are two adhesives, interior (which does not stand up to wetting) and exterior (which is not affected by long term wetting and would be called waterproof). Marine grade uses exterior adhesive, which is the same adhesive as used in the cheap CD-X plywood or any other exterior grade or "interior grade with exterior glue" plywood. With marine grade, the lowest grade veneer is "B", which means that there will be no serious voids on the surface and interior plies. It is the voids that cause poor adhesion! So, marine grade will have good adhesion throughout the lamination. Also, marine grade can be cut without getting a void in one laminate on a freshly cut edge. The edges will be totally solid. The two species used for marine grade are Douglas fir and western larch, although I have seen keruing and other species used in a product called marine grade. You can get the same performance from panels such as exterior AC in most cases.

[deckie]

Ok here we go...yepp u apply each coat whilst the other is tacky so its pretty quick to whack on..stays workable for hours after mixing too so that helps putting maybe 2 coats on with each mix... might even get 3 coats per mix. Doesnt say how long for full cure before putting anything over it but i'd guess maybe 24hrs minimum but u'll just need to wait and see on that one till goes hard. So maybe even 1-2 hrs tops then whack on another coat.

Good news is that u MIGHT be able to get away with 1 lt of each part a and b. Dont know but at least they make small tins if u get caught short. They base coverage on 5 coats which sounds a bit of overkill to me, but u definitely want 3 ...coverage rate (undiluted) says is 12-16 sqm/litre which i assume is a combo of a+b making up 2litres. Work out your area..double it for top and bottom and i'd go 2 underneath and 3 coats on top...any spare just keep whacking on the edges. After finishing check for bad drips under the edges to save on sanding. Give the edges a sand/tidy and round off a bit before using it. You'll find the flat surfaces set like resin (shiney smooth) after maybe 2 coats but the edges just keep soaking it up which is what u want..depends how much u sand the edges before applying.

DEFINTELY wear safety gear coz its thin and splashes a bit...plus you'll be working fast with the brush and it'll spatter. You dont want this crap in your eyes nor breathing in too much.

Actually when u think of it places like Bunnings sell only 2l or 4l of all sorts of stuff and having to buy a big tin of whatever will set u back about the same probably. May not work out as expensive as i thought.

[Screamin Semen]

thanks for the info Deckie your a great help...just abit confused on whether or not I am buying 2 seperate tins and mixing or buying a 1 pot mix as dan said earlier? I figured 1 of each of the following links? Or no?

https://www.whitworths.com.au/main_i...AbsolutePage=1 (https://www.whitworths.com.au/main_itemdetail.asp?item=60657&search123=everdure&intAbsolutePage=1)

https://www.whitworths.com.au/main_i...AbsolutePage=1 (https://www.whitworths.com.au/main_itemdetail.asp?item=60616&search123=everdure&intAbsolutePage=1)


Cheers. :)

[nigelr]

Norseal to seal then Botecote epoxy or Northane 2 pac marine poly on top.
Both these last two products contain UV inhibitors.
Not cheap or quick-drying but great Aussie products.
Using a decent face mask cartridge respirator is essential, especially with the 2 pac.
Not gluing the carpet down makes it easy to remove and clean.......done this with mine (5.3 runabout) and am happy with the result, I've been suprised (and delighted) with how little the carpet moves.

[deckie]

Mine are two tins part a and part b (activator) Mix equal quantities and stays good to use for maybe 5-6 hrs from memory.

if you;re predrilling the holes thats even better coz as u apply it'll soak into those too and seal the holes...just fill em up and watch out for drips underneath. You could dip the screws in some and put in or just use sika when u go to do the screws...at least the ply is presealed and this deck will likely last longer than you. Worth $ and peace of mind to any buyer if u want to sell one day..maybe take a piccy.

Yeah from that Whitworths i'd start with 1 litre of A plus 1 litre of B. Probably start by mixing about 250ml of each together and see how far that first batch gets you. If you think you;re right for quantity u could probably mix enough together to finish the job and apply another coat every hr or two till either the everdure is gone or the beer runs out....must reapply when still tacky tho. It'll last a good 20 yrs with a bit of care i reckon...and resusable/easy recovered as long as u dont overlaod with carpet glue that wont let go ;D

[sleepygreg]

MAIMAI.....if you would kindly review what you have posted as being an extract from a so called 'expert'.....you would be able to see that he is saying EXACTLY what I have posted. Though the language may be different, the principle is the same. The key is the core gaps. And the glue IS the same. FFS I have been using and selling this stuff for 35 years....i think i might know what I am talking about.

Sorry

rant over

PS.....please refer to ASA rather than overseas ratings....which some people tend to ignore when referring to things posted on the almighty 'net'.

[maimai]

MAIMAI.....if you would kindly review what you have posted as being an extract from a so called 'expert'.....you would be able to see that he is saying EXACTLY what I have posted. Though the language may be different, the principle is the same. The key is the core gaps. And the glue IS the same. FFS I have been using and selling this stuff for 35 years....i think i might know what I am talking about.

Sorry

rant over

PS.....please refer to ASA rather than overseas ratings....which some people tend to ignore when referring to things posted on the almighty 'net'.

and i also see guys selling boats for years and they also have NFI on what they talk about ::)

[oldboot]

There are two types of "marine ply" commonly sold in Australia.

Australian Standard Marine ply is quite expensive, but if it has the australian standard mark on it you know what you are getting.

The British Standard Marine ply, sorced from asia, is generaly not sold as marine here, but as exteriour grade...if ya get the better stuff it isn't bad, just not AS marine.

there are two types of glue commonly used in ply "A" bond which is "Resourcinol" and is long term waterproof and "b" bond which from memory is "urea formaldahide" which is not long tern waterproof...... but ya wont find too much "B" bond arround these days unless it is some sort of decorative interior veneered ply.

From what I see there are two schools of thaught in the wooden boat community.... the timber preservative school this is the everdure crowd, and the epoxy school.
They both have strong views, and the opinions you will hear are pretty polerised.

I tend to take the epoxy side......the modern marine epoxies are pretty damn good and they seal up timber and ply exceptionaly well...and do a whole pile of other jobs very well.

My preference is "boat coat", you can buy this direct from "boat craft pacific".

this is a new generation epoxy and is far less nocious that some of the previous stuff.

any of these products you need to apply at least 3 coats for a proper seal........but if it is done properly the new deck will outlast the boat...it will certainly outlast the carpet.

Yeh put the carpet down with spray glue, if ya must glue it down.....ya will need to get it up at some time.

.

cheers

[Roughasguts]

I would be using S/S press studs to hold the carpet in seems to work on my boat.
Doesn't slip and the carpet can be taken out rolled up, and soaked in a big bucket with Nappy San to keep it clean and kill the smells.

Cheers.

[oldboot]

I have to agree that I'm not keen on having permanently mounted carpet.

When I pulled the carpet out of my boat the amount of sand in and under the carpet was phenominal.

And no amount of vacuming of hosing will get it out while it is in place........I am firmly convinced that there is no such thing as clean carpet.

Even strung up on the line, I keep beating and the sand keep comming out.

These days both in boats and in buildings carpet is used because it provides an illusion and cover all the uggly things......when in truth it is one of the filthiest and uggliest things known to man.

Don't forget for best life you want to store your boat as clean & dry as you can, the moisture and filth just keeps hanging arround in the carpet.

cheers

[deckie]

I would be using S/S press studs to hold the carpet in seems to work on my boat.
Doesn't slip and the carpet can be taken out rolled up, and soaked in a big bucket with Nappy San to keep it clean and kill the smells.

Cheers.
yeah agreed the press studs are the way to go...but i have to ask ..

What sort of bucket have u got thats big enough to fit sections of marine carpet to soak with the nappisan ? Thats one big bucket alright

[oldboot]

Ya got a bath ? just don't tell the Mrs:-X

Smaller pieces will go in the laundry tubs.

I got a big plastic tub from bunnings for $50 that I use to flush the outboard......I recon you could get som big stuff in that.

cheers

[Roughasguts]

yeah agreed the press studs are the way to go...but i have to ask ..

What sort of bucket have u got thats big enough to fit sections of marine carpet to soak with the nappisan ? Thats one big bucket alright

Hey Deckie, my carpet is in 3 long sections down the guts of the boat so it will roll up and fit in one of those big plastic buckets with lids, only about 2/3 at a time but just turn the carpet roll around after a good soak to do the other end.

I use the ones builders use for tile cement or even the Maccas dill pickle buckets.

But a wheelie bin will do it and clean the bin at the same time.

Cheers.

[danners]

for the guys using s/s press studs, how are you securing them to the carpet and ply?

sorry for hijack
Dan

[Roughasguts]

for the guys using s/s press studs, how are you securing them to the carpet and ply?

sorry for hijack
Dan

Using a deep S/S screw, which reminds me to pull them out to seal them up properly, I bet Haines didn't!!!!.

Cheers.

[GLXMAN]

FWIW,
For structural work, that is bulkheads etc, marine ply is the way to go,

For non-structural work, like a floor, (cabin sole), for example, top grade exterior ply is sufficient,

In my last two yachts, 28ft and 34ft, that is what I used for all non structural work

As for sealing, I always used West Epoxy, why West Epoxy, well it cost more but was always reliable, and in addition, it can be mixed with a range of gluing modifiers etc

Seals against all water ingress, but it must be protected from UV, (the sun),
This just requires a coat of paint

Regards,
Gary

[Screamin Semen]

Cheers for the feedback guys much appreciated....quick question....will this stuff do the job for gluing carpet to ply?

http://www.parfix.com.au/products/live/114/24.asp

Cheers SS

[Screamin Semen]

Will this glue be strong enough to glue the carpet to the ply but will let go to be able to replace the carpet few years down the track?

http://www.parfix.com.au/products/live/114/24.asp

Cheers SS

[oldboot]

The last thing you need to be using to glue carpet down is anything in a tube....especially the crap from the building industry.....the liquid nails type producst are realy very ordinary adhesives.

You need to be looking at brushable/sprayable contact cement.

Put it on over the whole area with a brush or better still spray it with a normal spray gun.

If you are going to paint or seal your deck first.....you will need to sand it to provide a key.

very few glues will stick well to a glossy surface.

the press studds are certainly the best option if you are properly sealing the deck.

keep the boat properly covered and buy a good quality marine carpet and you will probaly never need to replace it.

with the press studs you will be able to get the stuff out and clean it properly...which is a real issue.

cheers

[deckie]

It'd work yeah but maybe a little too well.

If glueing many have found the contact adhesives in a can to be the go, coz they're cheap/water resistant and dont seem to break down in the heat. Plus you can put it on thin/sparsely with an cheapo brush.

I guess the moral of the story is to think when putting the carpet on that nicely preserved new deck, that it will likely need to come off one day. You dont need great quantities of any glue to fix it securely nor does it need to be tough stuff or anything fancy.