Pressure Treated or Not??

[Bob_VT]

Re: Pressure Treated or Not??

Just my oppinion, and i know i have said this before.

Why use resin? Pt plywood Will outlast your interest in the boat even if it got wet. If you are using pt plywood, then the resin is a waist of time and money.

I know there are a lot of people who dissagree with me on this point. But to me it just does not make sense to use resin on top of pt plywood. A pt transom will last a good 10+ years, if not a LOT longer. And at that point if i still had the boat, i would probably want to redo it anyway.

Just my oppinion.

Did you ever consider that people do not want to walk on an unfinished deck...... Naw you are right just leave it plain wood ....that would look fine on any ghetto repair

 

[NYBo]

Re: Pressure Treated or Not??

Did you ever consider that people do not want to walk on an unfinished deck...... Naw you are right just leave it plain wood ....that would look fine on any ghetto repair

You forgot to mention the splinters if anyone goes barefoot in the boat.

 

[Isaacm1986]

Re: Pressure Treated or Not??

Just my oppinion, and i know i have said this before.

Why use resin? Pt plywood Will outlast your interest in the boat even if it got wet. If you are using pt plywood, then the resin is a waist of time and money.

I know there are a lot of people who dissagree with me on this point. But to me it just does not make sense to use resin on top of pt plywood. A pt transom will last a good 10+ years, if not a LOT longer. And at that point if i still had the boat, i would probably want to redo it anyway.

Just my oppinion.

Did you ever consider that people do not want to walk on an unfinished deck...... Naw you are right just leave it plain wood ....that would look fine on any ghetto repair

Bob,

I don't ever recall saying that it was for the deck. I was talking about using it for the transom.

Besides, even if it was on the deck, there are a lot of products and solutions for "covering" the wood to a nice finished deck. Not really any different than covering a non PT deck, or a marine plywood deck. same solutions, same products will still work on a PT deck.

As much as you or anyone wants to deny it, the truth is PT Plywood IS a good choice to use in fiberglass boats. Will last a long time with NO RESINS, and allows people to spend the money saved from resins on other parts of the boat.

Maybe you should read what i type a little more closely next time, before you comment against what i have to say.

 

[NYBo]

Re: Pressure Treated or Not??

I'd rather use regular exterior plywood fully encased in glass cloth and resin than bare PT plywood of any variety- it's a lot stronger, and if done right, won't rot.

 

[Bob_VT]

Re: Pressure Treated or Not??

Thank you for the welcome. I am starting a rebuild project for an 18' shadow bass boat and everything is rotten, the only thing i am keeping is the hull! thanks for the advice, coming from the construction side made me think it was a no brainer till i came across a thread that suggested using exterior grade ply. i need it for the transom, stringers, and the deck. all of which i am planning on glassing in so i will not have this to do again while i own the boat!

while i am here, what about the foam that they use for the boat. it looks like they injected foam in pockets behind the transom, below the deck, and in two boxes in the back of the boat on either side. what is the purpose for the foam, other than support, and what is the best way to remove and replace it?

Glass it over the PT as stated in the glen L links Mark provided but it must be dry.

Or leave it ghetto and paint it right Attention to detail!!

 

[NYBo]

Re: Pressure Treated or Not??

Bare PT plywood WILL warp, properly glassed wood will not.

 

[tkms002]

Re: Pressure Treated or Not??

I never restored a rotten boat but I have built an entire 20ft center console from epoxy encapsulated solid mahagony and mahagony plywood. Epoxy encapsulated is the key here, not cheap polyester resins. Epoxy is completely water proof, polyester resins are not. They are more expensive but you will never have to worry about it again if done right. Read up on this before you start on the West system site. As far as the motor mount holes rotting out, here is what you do to COMPETELY PREVENT that.
Locate the place where you want the holes.
Drill holes that are 3/8 inch larger in diameter.
Completely fill these holes with epoxy thickened with 404 high density filler(West system products only). Before you fill the holes with the thickened resin brush on an unthickened coat to all exposed surfaces. This is so the epoxy soaks in a bit. The thickened resin will not soak in.
Allow a day for it to cure then drill your holes in the center of these filled holes. NOw you have a hole in epoxy, not in plywood.
PM me if you have any questions.
Bruce

 

[Chris1956]

Re: Pressure Treated or Not??

Isaac, Unglassed PT plywood will absorb water, and can delaminate. Also, I want my transoms to last as long as possible, 10 years isn't enough.

Bruce, Mahogany has a natural oil to it. It was used in wood boatbuilding for years because of this property. It is a good thing you used epoxy, and the poly resin is less sticky and won't bond as well. If you had build the boat out of another wood(not teak or other oily wood), poly resin would be just fine.

 

[Get-it-Wet]

Re: Pressure Treated or Not??

I have to apologize, when i asked the question as to what type of wood I did not realize what a slippery slope it was. It is obvious that I did not do enough homework on my own, but I have the PT ply, sounds like most of you are not completely against it, I am gonna let it dry because I have not gotten my transom area completely ground out. I also plan on cutting it up to the shape of my old transom and then weight it down and let it do some more drying. I do not know where you guys find the time to do all of this research, I barely have enough time to work, work on the boat, and check this website. I do hope that more people chime in with advice as this has helped me plan my boat restoration.

 

[Mark42]

Re: Pressure Treated or Not??

I have to apologize, when i asked the question as to what type of wood I did not realize what a slippery slope it was. It is obvious that I did not do enough homework on my own, but I have the PT ply, sounds like most of you are not completely against it, I am gonna let it dry because I have not gotten my transom area completely ground out. I also plan on cutting it up to the shape of my old transom and then weight it down and let it do some more drying. I do not know where you guys find the time to do all of this research, I barely have enough time to work, work on the boat, and check this website. I do hope that more people chime in with advice as this has helped me plan my boat restoration.

If you have a stud wall garage with space to tack the plywood to, its a good way to let it dry and not warp. Actually, it only takes a week or so to dry. The APA tests show that even with high moisture content, the resin will hold.

If you bought at a home center, chances are what you have is .25 CCA pressure treated. Its good. If you go to a lumber yard, the .40 CCA plywood is still available (although some may have to order it for you), but it is the exact same plywood the APA lists in their documents, regardless of what some other members say. Just read the documents I posted and you will know the truth. Members on this forum have been using PT plywood for years and there are no complaints. Only the people who don't use it complain (go figure).

Good luck with your project.

 

[ondarvr]

Re: Pressure Treated or Not??

There are many bits of helpful truth and fact strewn throughout this thread, but there are also some misconceptions.

PT will work fine and if you want a better grade buy the PT marine panels, they're 5 layer and of good quality, many boat builders use them. I have pieces of both PT marine panels and normal PT ply (3 layer) from various projects laying around, some have been on the ground for up to ten years and show no signs of rot or delamination, but the cheap ply does warp more. There are different grades (quality) of the cheap stuff, so you do need to check each sheet before you buy it. I?m not saying cheap PT is the best thing to use, but if you plan to use cheap CDX (which many people do), it will at least work that well. It does need to be dried before using it, as some sheets (or lumber) can be very wet.

In a glass boat the actual strength of the ply isn't quite as important, its mainly used as a durable, easy to work with core, the glass is supplying most of the strength. Unlike a plywood boat where the epoxy and glass are used to waterproof the wood and help glue it together but the wood is relied upon for the strength.

Epoxy is not waterproof, nothing is, but it is more water resistant than polyester. The so called penetrating epoxies are much less water resistant than standard epoxy and in many cases can drop down to, or below the level of VE or polyester resin.

Any fasteners use in the boat should be SS anyhow, so corrosion shouldn't be an issue unless its an aluminum boat.

 

[BillP]

Re: Pressure Treated or Not??

Wow, I've been away from this forum for 2 years and see the same deal about pt ply...except a few more now understand fact from fiction.

Any pt is fine for boat stringers, cores, floors and transoms. The marine version is already dried and the homedepot cdx isn't...so you have to air dry it before using. As Mark42 already posted...the APA did testing and found no difference in peel strength between treated and untreated ply with polyester resin. It isn't a myth. CCA pt is the best cheap pt ply to use (because it is let hostile to fasteners) and legally sold only for commercial use...but available at homedepot type places.

10+ yrs ago I rebuilt a 17'r with all pt wood and used epoxy for the glasswork. I hand selected the best sheets, cut the parts out and let them dry in my shop from several months to about a year. I still have the boat and it's as solid as the first day it was done. It gets beat hard and sits outside in Florida 24x7x365. Back then a lot of naysayers tell me it wouldn't work. Unfortunately they didn't do their homework and preached the use of untreated wood. Their 10 yr old projects are still subject to rot, mine isn't. If you want the wood to last a lifetime, whether it gets wet or not, use pt. If you think you can glass well enough to keep untreated wood 100% dry and never have rot...good luck and keep an eye out.

A previous poster says something about the glass being the structural part and the wood only a core. That is true if you don't know how to size the wood to match the glass for total combined strength.

bp

 

[NSBCraig]

Re: Pressure Treated or Not??

http://www.jamestowndistributors.com/userportal/main.do


Limitations of pressure-treated plywood
Many people ask about the value of pressure treated plywood. Often, pressure treated plywood is heavily warped. This is primarily the result of the high temperature and rapid moisture take up during processing. Some plywood delaminates during the process. In addition, some pressure treating methods incorporate water repellant materials. These materials can easily jeopardize bonding so you won't be able to glue or paint the plywood successfully. Generally speaking, pressure treated plywood may be acceptable for house projects but not for boats.


Anybody that takes advice from someone who thinks PT wood does not rot needs their head examined.

 

[Mark42]

Re: Pressure Treated or Not??

Wow, I've been away from this forum for 2 years and see the same deal about pt ply...except a few more now understand fact from fiction.

Any pt is fine for boat stringers, cores, floors and transoms. The marine version is already dried and the homedepot cdx isn't...so you have to air dry it before using. As Mark42 already posted...the APA did testing and found no difference in peel strength between treated and untreated ply with polyester resin. It isn't a myth. CCA pt is the best cheap pt ply to use (because it is let hostile to fasteners) and legally sold only for commercial use...but available at homedepot type places.

10+ yrs ago I rebuilt a 17'r with all pt wood and used epoxy for the glasswork. I hand selected the best sheets, cut the parts out and let them dry in my shop from several months to about a year. I still have the boat and it's as solid as the first day it was done. It gets beat hard and sits outside in Florida 24x7x365. Back then a lot of naysayers tell me it wouldn't work. Unfortunately they didn't do their homework and preached the use of untreated wood. Their 10 yr old projects are still subject to rot, mine isn't. If you want the wood to last a lifetime, whether it gets wet or not, use pt. If you think you can glass well enough to keep untreated wood 100% dry and never have rot...good luck and keep an eye out.

A previous poster says something about the glass being the structural part and the wood only a core. That is true if you don't know how to size the wood to match the glass for total combined strength.

bp

Hi Bill! Welcome back. No matter how much factual and test results published by the APA are posted on the forum supporting and even encouraging people to use PT ply in their boats, some folks just are in total denial about it. Facts is facts as they say. Can't argue with the facts. Unless you are in denial. LOL!

 

[Chris1956]

Re: Pressure Treated or Not??

Guys, CCA-treated wood is not longer avail to the homeowner here in NJ. Professional dock builders can still get the stuff, however.

The PT chemical used in today's PT wood is different than CCA and has been in use for 4 or so years. The new PT chemical is hard on galvanized fasteners, such that the Home Despot no longer carries galv screws. Galv nails are now double galvanized to withstand the chemicals.

 

[Mark42]

Re: Pressure Treated or Not??

Guys, CCA-treated wood is not longer avail to the homeowner here in NJ. Professional dock builders can still get the stuff, however.

The PT chemical used in today's PT wood is different than CCA and has been in use for 4 or so years. The new PT chemical is hard on galvanized fasteners, such that the Home Despot no longer carries galv screws. Galv nails are now double galvanized to withstand the chemicals.

Well, HD sold me galvanized wood screws and galvanized nuts/bolts just a few weeks ago. Maybe they still had them on hand?

 

[Yacht Dr.]

Re: Pressure Treated or Not??

This is a good read about PT ..

http://www.naturalhandyman.com/iip/infxtra/infpre.html

I never really liked the PT + fiberglass thing..but I guess if you have the time to make your materials sound with your project then it would be great.

One thing I do like about PT is the Insect factor. Yea. the water intrustion thing and so on..but Bugs are also a factor in your build.

Termites suck..ants suck..

Im not condoning..or condemning..Im just laying out some other perspectives on this.

I personally like the Marine grade. There are more lams in the marine compared to regular Ply..termites dont like the glue..just the wood. ( its not just about termites either.. ).

I would save up the cash for the right wood,glass,resin for whatever project you need to do. ( sometimes this..sometimes that ).

Welcome back BillP ( thats not flippant hehe ).

YD.

 

[ondarvr]

Re: Pressure Treated or Not??

That's a good link YD, thanks.

 

[NSBCraig]

Re: Pressure Treated or Not??

Nice link YD. Maybe someone else can read it

Some people they read something, misinterpret it's meaning and use it over and over like it's evidence.

The APA does not anywhere say you should use homedepot PT. That's simply not true.

They do say they tested PT ply but in no way do they say it's low grade construction ply. (I was thinking grade of actual ply not also treatment as stated in YD's link)

If someone feels they need PT ply they should buy marine PT ply. It is made for this purpose.

PT wood rots!

PT wood soaks up water and delaminates!

Now since this nonsense continues we have people making crazy statements like you'll be fine without sealing it or you can dry it if your transom does get wet or slap some PT on the inside of your transom and that will fix it.

All horrible completely unfounded advice, stuff that everyone on here should quickly point out because someone just logging on doesn't know how wrong it is.

If you guys want to actually present some evidence (not the same report you keep misquoting) we'd love to read it but you've found none.

The people that build boats completely out of ply don't use it.

The wood boat guys don't use it.

Boat builders still use marine ply (non PT marine) not home depot stuff.

Are all these people just stupid? Do builders that have tens of years experience just not know that you can run down to home depot?

 

[Mark42]

Re: Pressure Treated or Not??

This is a good read about PT ..

http://www.naturalhandyman.com/iip/infxtra/infpre.html

I never really liked the PT + fiberglass thing..but I guess if you have the time to make your materials sound with your project then it would be great.

One thing I do like about PT is the Insect factor. Yea. the water intrustion thing and so on..but Bugs are also a factor in your build.

Termites suck..ants suck..

Im not condoning..or condemning..Im just laying out some other perspectives on this.

I personally like the Marine grade. There are more lams in the marine compared to regular Ply..termites dont like the glue..just the wood. ( its not just about termites either.. ).

I would save up the cash for the right wood,glass,resin for whatever project you need to do. ( sometimes this..sometimes that ).

Welcome back BillP ( thats not flippant hehe ).

YD.

Thanks for that post, even if it is all about home construction and not marine applications. But it does support what so many other people have been saying about using pressure treated lumber in boat building. Its just a good thing, just like the APA says.

Some folks will just never get it. They continue to be in denial, and will continue to mis-direct members, even if well intentioned, it is still in correct info. Just read the APA docs. The facts speak for themselves.

LOL!!!!!