Boat False Floor...Help?

[Yoodles82]

I'm putting in a little false floor in my 3 1/2 meter tinnie.

I have the carpet and some aluminium framework to weld on (with the help of my bro)...but have a few simple q's.

What sought of plywood should i get?? Where from?

And what do i glue the carpet on with?

Has anyone had any problems doing this that they anticipate i will have???

Cheers

Nat

[thousandyards]

marine ply.....seal it to be safe. might be worth another visit to whitworths or somewhere to hit them up for some advice. make sure you're using the right screws too - if you get the wrong ones and it sets up electrolysis in your boat it'll stuff it.

otherwise, i'll ask my old man - he's put floors in a few of his boats without any followup hassles.

[uglyfish]

marine ply for sure mate,i used liquid nails to glue my carpet down...worked a treat..no need to worry bout screw holes starting the rotting prosses or electrolises...

[shortie]

always seal your ply. I generally just give mine a good coat of paint.

For sticking on the carpet i use contact adhesive. Spray it on if you have the capabilities and facilities.

[Bri The Pom]

Nat

make sure you use plenty of supports for the ply and that the ply is thick enough.also make sure you screw it to the framework as much as you can because over time the weight and jumping around, the floor could start to sink and warp.

I had to replace my floor and i used 19mm formply.

Just a thought i put a hinged part of the floor for storage under the floor.try and think ahead will this be of use to you if so do it now,i can photograph mine if you wish or have a look.

Bri.

[AZZA]

You will proberly fall down when you find out the price of marine ply. as the ply wont be imersed in water continuously if you use a good quailty structual ply it will be a lot cheaper, just be sure to seal it. I would use a latex based water proofing product as it will be flexable and if you can keep the interior of the boat dry when out of the water even better.

PS what barra stick did you end up getting?

[Yoodles82]

Yeah, i don't expect to get the floor that wet, but you never know

Az, i ended up getting the cheap abu garcia overhead in the bcf catalogue...i'll start with that and once i get the hang of it, i'll move up the ranks :cheer:

Try and get myself sorted this weekend, with a bit of training from my brother.

Although, i was thinking of going back and getting the shimano sahara combo too...i'll eat rice and bbq sauce this week to afford it;)

What thickness ply do you reckon??

[AZZA]

I would go 16mm to keep wieght down but that would depend on frame spacing

[bigtez]

Forget marine ply, only difference is in the finish and unless you are going to polish it up or varnish it there is no point in spending the extra $$$$$$$$$$'s. Sealed structural ply (15mm is what most of the tinnies I have seen come with)will do the same job at half the price.

Use a latex backed carpet and some contact adhesive to stick it down.

Terry

[AZZA]

There is also some board products made from recycled plastic ( you know how us city folk like to think we are green:P ) that would not need any treatment one type iswww.plaspanel.com.aunot sure on cost these days

[Yoodles82]

There is also some board products made from recycled plastic ( you know how us city folk like to think we are green )

Hahaha, i was wondering when i would get a bite from that one:laugh:

No one responded...i was so disappointed!!

That's actually not a bad idea though...you might even be able to forget the carpet then.

[bigtez]

Just be careful with some of the plastic 'ply replacements' available. We have seen a few that don't stand up to our harsh sun and UV. If you can check, what applications are covered under warranty, with the manufacturer/distributor.

[AZZA]

You would need to get a textured one as I have some on the back of my boat and it can get a bit slippery when wet so it has carpet fitted with press studs , makes it easy to remove for cleaning. My last boat was blue carpet over form ply , it could get realy hot under foot till you found yourself pouring buckets of water on the floor, also the type of carpet was as hard as buggery to clean as every thing would stick in it. Now the carpet I have is easly removed and hung on the fence to be cleaned with my tank water.

[rayke1938]

I do not glue my carpet down . I cut it a bit oversize so that sinkers and prawns/small fish cannot fall through to bottom of boat. When i am prawning or castnetting in water with a lot of debris and mud is is simple to grab the edge of the carpet and drop it over the side and give it a quick rinse.

I use an indoor/outdoor carpet that is self draining and just hang it on the fence and give it a good rinse with the hose and all the mud and gunk runs out and its dry in half an hour.

If you use a backed carpet it holds the moisture and gunk and gets smelly. Also not good for the life of the floor.

In my bay boat the floor is 12 mil structual ply but it has plenty of under floor bracing and in my dam boat the floor is 16mil with no bracing the floor is just supported where it sits on the ribs.There is no spring in either of the floors and the floor of the dam boat is also supporting the weight of 3 120a/h deep cycle batteries.

I do not have the floor screwed down in either of my boats. I just make it a neat drop in fit. If you screw it down the screws tend to corrode in with a white deposit around them and if you dont remove them every 6 months of so you will have to cut them out to remove the floor.

Structual ply is fine just seal the edges. If you are going to paint it paint both sides to prevent it warping. I use non slip paving paint. it does tend to hold the dirt but its worth it . Nothing worse than losing your footing on a wet deck.

Cheers

Ray

[noname]

buy more timber than you need, you know that bloody annoying bit in tinnies in front of the front seat, that section where the v is at it's deepest and you find it hard to do anything in that space, so maybe think about a little floor there or casting platform, good spot for your fuel tank, or anchor in a bucket, reguarding carpet, you need to be able to work with it around some tight turns, so a relatively soft carpet is going to be better than a real heavy style carpet, eg. the striped marine carpet. i would recomend sealing the timber used, as i have seen, but not experienced myself, edges curling up after being wet, normally out on the sides where not fixed down, once all is said and done, give it a hack out at least twice a year. hope this helps.

rob

[Yoodles82]

you know that bloody annoying bit in tinnies in front of the front seat, that section where the v is at it's deepest and you find it hard to do anything in that space, so maybe think about a little floor there or casting platform

Yep...i'm putting a small casting deck ontop of that section...on top of my front seat up to the cargo area...put a hatch in it to get below it, for anchors and whatever else:)

It'll be hard getting the angle right though!

[AZZA]

Use cardboard to template any angles you need

[Yoodles82]

Yeah that makes sense!...good idea.

[hairyweasel]

I did mine 3 years ago. Before I started I researched it on the net. The plywood manufacturers at the time recommended marine ply for anything that is submerged.

It said that waterproof ply was ok for decking.

I went with 16mm waterproof ply and it was a fair bit cheaper than marine ply.

I sealed it well before screwing it down with stainless screws. It's still as good today as the day I put it down.

[bigtez]

Thought this might be a good spot to stick a bit of info about marine carpets. Some of the following info is based on my experiences as a fisho and a marine trimmer as well as the 30yrs experience as a trimmer that Dad was able to pass on to me.

There are 3 main types of marine/outdoor carpet.

1. Head and Hull Liner: As the name implies, this is used for lining cabins and bulkheads. It is thin and is easy to manipulate into shape.

2. Latex Backed Floor Carpet: This is the most commonly used carpet to cover false floors in tinnies and the floors in glass boats. It is similar to the head and hull liner but has a stiff membrane backing. As this carpet will breath it won’t trap moisture underneath it and rot floor boards. It is also very light weight compared to the next group of carpets.

3. Woven Backed Outdoor Carpets: These are usually the most expensive carpets as they have a plush feel underfoot and are very sturdy. Most cut pile or ‘hook free’ carpets fit into this category. I have noticed that some of these carpets will separate from their backing when fuel or other chemicals are spilt on them. There is also some outdoor carpets available with a rubber backing over the woven one to stop them slipping when layed loose.

When picking a marine carpet there is a few things to look for.

The first thing to decide is how it will be laid. If you are gluing it over boards, as you would in a tinnies false floor, it needs to be sturdy enough to cope with being walked on but flexible enough to bend around tight corners. Latex backed floor carpets are good for this.

If you are laying the carpet loose, with either a non skid backing or press studs to hold it in place, the carpet will need to be bound around the edges to prolong its life. You will also need to remove the carpet as often as possible to ensure the floor underneath is kept dry.

The next thing to consider is the materials the carpet is made of. Fully synthetic carpets are ideal as they will not absorb water. Some of the woven backed carpets use natural fibres in the backing and are more suited to being permanently glued in place. Loose laying these carpets can allow them to move and where the coatings over the natural fibres. Latex backed carpets are usually fully synthetic.

Loop pile or cut pile is also a consideration for fishing boats. Cut pile carpets won’t get hooks stuck in them. Loop pile carpets will get hooks stuck in them but they also have the added benefit of sticking to hook side ‘velcro’. However if you choose one of the loop pile carpets with a smaller diameter fibre hooks are easily removed and ‘velcro’ will still stick to it.

You will also need to consider the chance of fuel or chemical spills on the carpet. If it is a significant risk then one of the latex backed carpets would be more resilient.

[Feral]

I'll add to that that dont forget that the mats and rolls in most "hydrocarbon spill" kits are polypropylene and will suck up fuels and oils like a sponge (and not let them go), so perhaps not the best choice of materials around the engine area! (Unless your making your carpet sacrificial!)

[Yoodles82]

That's great guys, very helpful!

Thanks alot.:cheer:

I'm still torn on whether to go for marine ply or not. It hardly seems worth it, cause the boat is about 20yrs old anyway...so i'm not sure the floor will have to last that long anyway:-)

[AZZA]

The glue used in marine ply is the same as structural ply,marine ply like structal ply will delaminate and wrap if not sealed and so in your application marine ply in not needed.the stacer I had befor this boat had a form ply floor unsealed and it was 4 years when sold with no problems.

[AZZA]

The other differance with marine ply (mp) to structal ply (sp) is mp will have more laminations to the same tkickness giving it a greater tensile strenth. eg 12mm sp will have 5 layers where 12mm mp will have 7 layers .

[Yoodles82]

So you get what you paid for with marine ply then.

Would i still have to seal mp with paint?

If so, shouldn't i just get structural ply? Or should i get formwork ply cause it already has kindof a seal on it?

What would you suggest for a just that i would like to last about 5 yrs, and wouldn't see saltwater that much?

[Brian D]

Good info there but I'll tell you what I did in my tinny. 22mm formboard accross a 1400 x 1400 area.

Me being an accountant who is crap on the tools, had no idea so when I got the huge sheet home it wouldn't fit. Something about 8x4 not the same as 1400x1400.

So I had to use one of those things, you know a saw'ie thingo with power in one end and distruction on the other. Stuffed that bit of wood up didn't I, so I somehow stuck the peices back together with other bits underneath and plaster board glue left over from the house reno.

I have connected the floor to some cross pieses on the boat (might be struts or something), not sure but they were there. I just hope the 30mm wood screws didn't go through the hull. I have only managed to connect 3 courners because I stuffed the cut and needed to fill the hole with sproay expanding foam before I stoll the wife's floor mat and covered the lot.

It holds 2 fat blokes and heaps of gear.

Need any more help?

[Yoodles82]

mmm...yeah, thanks for the argh 'help':unsure:

Sounds like you've done a fine job:-)

[bigtez]

Go for whatever is cheapest and comes in the thickness you need and just seal it. There is no necessary advantages in the more expensive plies when doing a floor in a tinny.

[AZZA]

I will say it slowly for the country folk this time;) structal ply will be fine will do the same job as mp or fp but cheaper

[Yoodles82]

I just had to clarify...all this city jargon is doin my hick head in;) :laugh:

[maxi]

well said azza....why did it take so long ... :silly: just make sure you sand the edges well after you have cut the right size, take all the burrs off from sawing etc ... the give 2 coats of good quality 'exterior' low sheen house paint. glue will stick fine to this paint ... have fun ... :P