plasti wood instead of wood that rots?

[badman]

This might have been covered before but has anyone thought of using that plaswood - recycled plastic wood instead of ply and timber in stringers, transoms and floors?
It doesn't rot and i believe you machine and cut it on woodworking machines, just like wood.
I have seen it in the flesh on some park benches nearby and it looks very long lasting.
Anyone tried it or have any ideas?
nice one
matt

 

[redfury]

Re: plasti wood instead of wood that rots?

jscersca used it for his outer stringer on his glastron if I recall correctly. My only beef with using it is the possibility of it expanding and contracting more than the fiberglass and causing problems down the road after repeated movements....but then again, wood is going to move to a certain degree also.

Bonding resins other than epoxy would be questionable, and John used Epoxy on his....couldn't break the bond with two pairs of monkey wrenches...

 

[badman]

Re: plasti wood instead of wood that rots?

hey had a look at the chaps work. wow, he really worked on that boat!
Shame he used cheap softwoof for the stringers. i would have chosen a hardwood that likes water (in the UK Ash is a good one) and shaped that in.

On your thought about plastic expanding and contracting ... Can't say i think it would actually do that.. not like wood.
I have built many timber frame lightweight buildings using various wood species and wood REALLY moves about. Its natural after all.
Can't say i have any recollection of a plastic doing that. Which is why i thought it would be good.
However, i reckon this plaswood is probably heavier than softwood due its density. Probably more akin to Oak?

If i cared about my ?50 boat enough i would probably look into buying in some of this stuff.
Perhaps on the next boat i get! Hopefully a 20 ft half cabin job.
Cheers hey.
matt

 

[ezmobee]

Re: plasti wood instead of wood that rots?

Plastic absolutely expands/contracts with weather. I have some plastic lattice work under my deck at my house and it expands/contracts big time and gets all warpy.

 

[huskerdaninva]

Re: plasti wood instead of wood that rots?

I would not reccommnd using the "plastic" wood if what you are referring to is the recycled plastic milkjugs type used for decking. While it is rather maintenance free it has nowhere near the structural strength or integrity of conventional lumber. As an example, I know when using this product in deck construction the support joists need to be considerably closer together than with regular lumber because the product really is not designed to rival the weight bearing capacities of lumber. Just one man's opinion.
Dan

 

[BobsGlasstream]

Re: plasti wood instead of wood that rots?

True enough plastic will not rot like wood but it also does not have the strengh of wood. Plastic will become brittle with age as it oxidizes and loses it plastisol. It may wook but I'm not willing to take the chance.
Good luck with your project.

 

[redfury]

Re: plasti wood instead of wood that rots?

Well, I think the biggest misnomer about stringers is that the material used to make them has to be strong. It doesn't. They use foam core construction for stringers all the time. Unless you plan to only tab in the stringer and use the material for its strength, the strength will be in the fiberglass. That being said, going with a heavy plastic wood as basically a rot free form isn't doing a whole lot of good other than adding weight.

 

[Azonic]

Re: plasti wood instead of wood that rots?

What about delron, teflon, or acrylic?

Lots of strength, little weight, and rott free...

I know we use Delron here in our plant for tons of applications where wash down is required constantly....

Just a thought...

However, a 2" thick 4'x8' sheet of delron would cost more than some boats...

 

[109jb]

Re: plasti wood instead of wood that rots?

If we are talking about a fiberglas boat, I would just use pressure treated and be done with it. It IS wood and it WON"T rot. It also isn't expensive and is readily available.

As far as the wood only being a form and not providing any strength, you are incorrect in the vast majority of boats out there. Sure you can make it so that the wood is only a form, but that isn't the way most were built from the factory. There are some exceptions, but as I said, most DO use the strength of the wood. As an example, my Sea Ray only had the stringers tabbed to the hull and a little extra chopper gun strands sprayed in for not so good waterproofing. If the stringers had the equivalent of 1 layer of csm I would be surprised. Oh and did I mention that the stringers were only tabbed on the inboard side (inside ski-locker and fuel tank compartment). The outside edges of the stringers were not tabbed to the hull and appeared to only have a coat of bare resin. In short there wasn't enough fiberglass there to provide any strength.

 

[ondarvr]

Re: plasti wood instead of wood that rots?

Its been discussed here many times.

The properties of each product.

Plastic

Low strength.
High cost.
Heavy.
won't rot (at least most of them won't).
easy to work with.

Wood

High strength.
Low cost.
Light.
Rot varies on type of wood and workmanship.
Very easy to work with.


While there are many products out there that can be used, wood just happens to be the most affordable and works very well.

 

[forgedin78]

Re: plasti wood instead of wood that rots?

If your talking about the composite decking boards, like Trex, or timbertech, they may not actually rot, but the are not waterproof.

They are plastic bits and sawdust put together with heat and glue. If they are used on a deck where water is allowed to pool or the lay in water, they will swell up and fall apart. They need to be well drained, with plenty of space between the boards to dry themselves out, or they will fail. Even faster than PT wood actually.

 

[benjh1028]

Re: plasti wood instead of wood that rots?

I am planning to use composite wood next month when I start restoration of my 1995 Larson. The stringers will be structural plastic which contains fiberglass. For decking I plan on using 1/2" HDPE, which can be ordered as one piece. I plan on constructing extra bracing where needed (under captains chairs). Looking at the engineering specs, shrinkage is less than wood. If you can find a local source, price is comparable to doing a "real wood" project as shipping can be expensive. I've read the cons here, but the engineer in me says it can be done! l'll take lots of pics.

Ben

 

[ondarvr]

Re: plasti wood instead of wood that rots?

Ben

Let the engineer out. LOL

HDPE is not a good product for a floor, its heavy, weak, slippery, pricy and many types aren't very UV resistant, why do think its not used now. Can you use it... yes... is it the best product for a floor...not by a long shot. If you want a non rot floor, use a honeycomb product with a fiberglass skin on each side...its light, strong, you can put a nonskid surface on it and even glass it to the hull and/or each other. That's what I have in my boat.

What type of stringer core is it?

 

[benjh1028]

Re: plasti wood instead of wood that rots?

ondarvr,

You made me rethink my plans. Still going the composite route, but decided to use Coosa Composites Bluewater 26. Found it local and ordered a few sheets. It's $200/sheet, but should outlive me.

Ben

 

[Mark42]

Re: plasti wood instead of wood that rots?

I used plastic on my hard top project. The PVC molding was used around the side windows to support the slide tracks. I quickly realized when working with the stuff it is not suitable as a structural component in a boat. I ended up epoxying the pvc to the side of the hard top with a few ss screws as backup. Those pvc strips support 1/4" tempered glass windows and have been in rough water taking are real pounding. Because they were epoxied on, the pieces have held up fine. No signs of separating. And no worries about wood rot.

Showing how the track and molding go together.

Placement on the top.

Finished install of PVC molding and slide channels with glass:

 

[badman]

Re: plasti wood instead of wood that rots?

ondarvr,

You made me rethink my plans. Still going the composite route, but decided to use Coosa Composites Bluewater 26. Found it local and ordered a few sheets. It's $200/sheet, but should outlive me.

Ben

I reckon that material sounds good but can be found cheaper...

Put on a high vis jacket, grab a screw driver and a battery powered drill and go for a walk down to your nearest bus stop after dark... Preferably WAY after dark.

Proceed to 'REPAIR' the thick plastic and perspex sheeted walls and remove all and anything even similar to your abode.

Hey presto.. You have just committed an offence and are now the proud owner of some.. uh, plastic stuff that may or may not be suitable for boat building.....

Just try it anyway!
****, that gives me an idea!

Refurb your under-floor stringers and whatever, clean it all up and glass it in.
Install a 12 volt insulated cable pair with a few led lights at intervals under there.
Lay down a few sheets of perspex and glass in.
Operate switch to illuminate under-floor lighting live happily ever after knowing that you can check the condition of your boat flooring at any time....
Plus, at night, whilst fishing you won't be able to see any lights or landmarks due the brightness of the floor.... It will be dangerous but you'll be the only boat out there with a disco dance floor.

Going off to do it with mine RIGHT NOW!

 

[benjh1028]

Re: plasti wood instead of wood that rots?

****, that gives me an idea!

Refurb your under-floor stringers and whatever, clean it all up and glass it in.
Install a 12 volt insulated cable pair with a few led lights at intervals under there.
Lay down a few sheets of perspex and glass in.
Operate switch to illuminate under-floor lighting live happily ever after knowing that you can check the condition of your boat flooring at any time....
Plus, at night, whilst fishing you won't be able to see any lights or landmarks due the brightness of the floor.... It will be dangerous but you'll be the only boat out there with a disco dance floor.

Going off to do it with mine RIGHT NOW!

I like it! I've been thinking about how to put neon lights under the boat, but this idea is way better - and now my subwoofers won't look out of place! Plus, I've always thought boating with a leisure suit would be a great look (even better than the European Speedo).

Actually, ended up getting it for $139/sheet. One of its recommended uses is for marine flooring. Specs are here: coosacomposites.com.

I'll either triumph brilliantly or fail spectacularly...................

Ben

 

[Mark42]

Re: plasti wood instead of wood that rots?

I think there are lots of good uses for plastics on boats. Like rod racks, shelving, dash boards, seat frames, storage boxes, etc. Basically anywhere that stress is low and strength does not have to be high and traditionally has been an area of rot, like seat bases, battery tray, etc.

 

[badman]

Re: plasti wood instead of wood that rots?

i think i am going to find the source and brand name for the plaswood that is used here on a park bench.
It's VERY tough.
Like i mean bomb proof, with no bending under weight, even a little.
If i can find the maker i will ask to test the same product at half the thickness to see if it bends.

Can't imagine it will have as complex a grain as wood... which is wood's saviour but they may have had a play with multi-directional plastic layers.

Just what we need... Carbon Fibre street furniture!

 

[ondarvr]

Re: plasti wood instead of wood that rots?

If you're using Plaswood in a generic way, referring to all types of plastic decking, then you'll need to find the exact product you're talking about. If you?re actually talking about Plaswood, then the description from their website indicates it may be very similar to Trex, they say its recycled plastic and recycled wood.

Trex has issues and I would expect similar products to have similar issues. It also showed no examples of the product being used in a structural way other than for decking or benches.