[MrSnook]

I would like to make some sort of cover to go over the large area in the back of my Gheenoe. Right now wood looks to be the least expensive bet. I've found some marine treated plywood at Lowes but I'm wondering do I need to put a layer of fiberglass over it and encase it or could I just paint the wood with a good quality marine paint?

If I have to go the fiberglass route what is the best wat to go about it?

Thanks

 

[firecat1981]

Yes you will want to coat it because if not it will split and check on you. At lowes they sell a fiberglass resin repair kit, usually from bondo, in the paint area. Should be all you need for this project. Prime with the epoxy and wait 20 minutes, then One layer of cloth should do you well, then a gloss coat, sand and paint.

 

[MrSnook]

Great thanks for the response, can I assume that the gloss coat you mentioned is included in this kit? Also will any type of marine paint work?

Thanks

 

[firecat1981]

Gloss coat is just rolling on another batch of resin once the first one sets up, it makes sanding much easier and this way you won't grind off half your fiberglass. Any marine paint will work, just follow the prep instructions on the can. Lowes sells rustoleum marine paint for $11 a can.

 

[jms]

I would like to make some sort of cover to go over the large area in the back of my Gheenoe. Right now wood looks to be the least expensive bet. I've found some marine treated plywood at Lowes but I'm wondering do I need to put a layer of fiberglass over it and encase it or could I just paint the wood with a good quality marine paint?

If I have to go the fiberglass route what is the best wat to go about it?

Thanks

if that wood is "pressure treated",nothing will adhere to it,you can't put anything on top of pressure treated wood - it will pop off.
i do not believe "bondo" products are epoxy based

 

[firecat1981]

Marine plywood is not pressure treated, just made with a better, sometimes, glue and usually fir from the box stores. Really you don't need marine ply for a deck, especially one that will be coated, just bcx will do you fine as long as you seal it well.
The bondo repair kit I've seen there is epoxy resin and 3sq ft of cloth with a spreader. But for this project you could get away with boatyard resin since it is not structural and the coating is only for checking under the paint.

 

[jms]

Marine plywood is not pressure treated, just made with a better, sometimes, glue and usually fir from the box stores. Really you don't need marine ply for a deck, especially one that will be coated, just bcx will do you fine as long as you seal it well.
The bondo repair kit I've seen there is epoxy resin and 3sq ft of cloth with a spreader. But for this project you could get away with boatyard resin since it is not structural and the coating is only for checking under the paint.

well aware of the difference between marine grade ply - "treated" ply,was what i was referring to - "treated" wood,usually refers to pressure treated - the reason for my reply...

 

[DuckNut]

Agree with kreepa...never seen marine wood at a big box store.

 

[Swamp]

Store to store whether they carry it or not. Ft Myers area does not, both of the big box stores have it on their web page but not as a stock item here. That does not change the question of whether the OP has marine ply or pressure treated.

Swamp

 

[firecat1981]

I've seen marine grade ply at both Lowes and Homedepot, but only ones near the water. It's douglas fir wood with waterproof glue (don't know if it's melamine glue or phenolic glue). That being said it is ugly looking ply. Tons of checking and splits, I think it's usually used for redecking pontoon boats and covered in carpet. They definately don't sell meranti or ockume. I have never seen marine pressure treated plywood before at any store although I'm sure it exists for some reason. From his original post I got the impression he hadn't bought it yet, I'd still go with BC exterior plywood, glassed and painted it will last for decades.

 

[jms]

I've seen marine grade ply at both Lowes and Homedepot, but only ones near the water. It's douglas fir wood with waterproof glue (don't know if it's melamine glue or phenolic glue). That being said it is ugly looking ply. Tons of checking and splits, I think it's usually used for redecking pontoon boats and covered in carpet. They definately don't sell meranti or ockume. I have never seen marine pressure treated plywood before at any store although I'm sure it exists for some reason. From his original post I got the impression he hadn't bought it yet, I'd still go with BC exterior plywood, glassed and painted it will last for decades.

incorrect - marine grade ply is finish sanded on both sides - no splits or checking - no voids either...

the ply you're referring to is exterior grade cheap crap - that's not marine ply

marine grade ply,it's something i've never seen at a store like home depot or lowes - marine grade ply is very expensive compared to other stuff - example - one transom i replaced in a customer's rig - the lumber invoice was almost $700 - special ordered 5'x10' pieces - 2 3/4" and 1 1/2"...

marine ply is a different make up,however,no imperfections are on either side...


from, "engineered wood"

Marine-grade plywood is made entirely of Douglas-fir or Western Larch. The grade of all plies of veneer is B or better. B-grade veneer may have knots but no knotholes. A-grade veneer has no knots or knotholes. Both A and B grade may contain wood or synthetic patches. Panels are sanded on both faces or Medium Density Overlay (MDO) or High Density Overlay (HDO). The maximum core-gap size permitted is 1/8 inch. Its exposure durability rating is EXTERIOR and the glue used is a fully waterproof structural adhesive. It is considered a "premium" panel grade for use in situations where these characteristics are required. It is available in 4x8-foot sheets of 1/4, 3/8, 1/2, 5/8 and 3/4-inch thickness. Sheets up to 5x12-feet are also available. Available grades are A-A, A-B, B-B (face-back), MDO and HDO.

 

[firecat1981]

incorrect - marine grade ply is finish sanded on both sides - no splits or checking - no voids either...

the ply you're referring to is exterior grade cheap crap - that's not marine ply

kreepa no offense but you obviously haven't done much research on the topic. Check out my boat build in the bragging section, I did months of research on this one and the last one I built and learned alot about the different types of marine plywood and visited several distributors to physically check the boards. There are almost as many grades and variations of marine plywood as there species of trees.

Yes there are marine plywoods that check, actually most of them will including occume in some cases. Yes there are grades of marine ply that have voids, and yes there are some that are not finish sanded beyond a b grade. And no I'm not refering to BCX plywood, which isn't crap if you actually know what you are doing with it and use it in the right applications.

marine grade ply,it's something i've never seen at a store like home depot or lowes - marine grade ply is very expensive compared to other stuff - example - one transom i replaced in a customer's rig - the lumber invoice was almost $700 - special ordered 5'x10' pieces - 2 3/4" and 1 1/2"...

Yes certain box stores carry it, is it the nice bs1088 stuff, no, but it is marine graded plywood and has it's uses. It is slightly more expensive then hardwood ply and is good in certain applications. Not all marine ply is expensive, what kind are you using?

marine ply is a different make up,however,no imperfections are on either side...

Wrong again, even bs6566 allows for some minor surface patching and voids. All marine ply really means is it uses waterproof glue. The grade of the ply dictates the surface veneers and core materials and make up.

The website you quoted is talking about the marine ply available from that manufacturer, not marine ply in general. In fact most serious composite boat builders won't even use it because it is made from fir or larch and will check like crazy unless fully encapsulated. The 2 main players in this field is meranti and occume, both from over seas and even though there are many variations again BS1088 is the higher standard most would perfer, but isn't always needed. Do a little more research and you will see there is a very diverse market beyond what you know.

PS I see you are new here, welcome to microskiff.

 

[jms]

incorrect - marine grade ply is finish sanded on both sides - no splits or checking - no voids either...

the ply you're referring to is exterior grade cheap crap - that's not marine ply

kreepa no offense but you obviously haven't done much research on the topic. Check out my boat build in the bragging section, I did months of research on this one and the last one I built and learned alot about the different types of marine plywood and visited several distributors to physically check the boards. There are almost as many grades and variations of marine plywood as there species of trees.

Yes there are marine plywoods that check, actually most of them will including occume in some cases. Yes there are grades of marine ply that have voids, and yes there are some that are not finish sanded beyond a b grade. And no I'm not refering to BCX plywood, which isn't crap if you actually know what you are doing with it and use it in the right applications.

marine grade ply,it's something i've never seen at a store like home depot or lowes - marine grade ply is very expensive compared to other stuff - example - one transom i replaced in a customer's rig - the lumber invoice was almost $700 - special ordered 5'x10' pieces - 2 3/4" and 1 1/2"...

Yes certain box stores carry it, is it the nice bs1088 stuff, no, but it is marine graded plywood and has it's uses. It is slightly more expensive then hardwood ply and is good in certain applications. Not all marine ply is expensive, what kind are you using?

marine ply is a different make up,however,no imperfections are on either side...

Wrong again, even bs6566 allows for some minor surface patching and voids. All marine ply really means is it uses waterproof glue. The grade of the ply dictates the surface veneers and core materials and make up.

The website you quoted is talking about the marine ply available from that manufacturer, not marine ply in general. In fact most serious composite boat builders won't even use it because it is made from fir or larch and will check like crazy unless fully encapsulated. The 2 main players in this field is meranti and occume, both from over seas and even though there are many variations again BS1088 is the higher standard most would perfer, but isn't always needed. Do a little more research and you will see there is a very diverse market beyond what you know.

PS I see you are new here, welcome to microskiff.

the ply i quoted - as with all wood,needs to be fully encapsulated - encapsulated in a waterproof coating - as with all wood -failure to fully encapsulate it,will result in troubles down the road - any quality boat builder knows that.composite boat builders using wood ? huh ? the idea of a composite boat,is to be free of wood,perhaps you're confused ?
i purchase marine grade ply,from a local distributor - sj lumberman's supply -
after 20yrs in this biz,i've yet to see marine grade ply with voids or surface checking,or splits for that matter.never   seen any with surface imperfections either...there's a big difference between "doing research" and actually using the products - kinda of like electrical wiring - there's tinned marine grade,and there's not -both will work,one will last and resist corrosion,one won't.plywood - it all comes from trees - will CDX grade hold up in a boat ? i've replaced quite a few older prolines,with a transom core made from cdx grade ply - those were over 10yrs old-my old 31 bertram has alot of wood in it - that boat was built in 1973,no problems with dry rotting wood anywhere-the bulkheads,and any other structual members are made from a true marine grade ply-same deal with the 1975 blackfin i just finished cutting the deck up in,to replace fuel tanks - the wood core of the deck was dry - even checked it,out of curiosity with my moisture meter - wanna guess what that core's composed of ?...if you're gonna do something,do it so it lasts - use the best materials available - you're only as good as the materials you use - old saying,hold very true.i've never used a piece of marine grade with checking,or splits - i wouldn't accept the goods - again,only marine grade i've ever seen,or used is AA-no voids,no imperfections - "research" on the internet and actual experience are 2 very different things.personally,i'm not aware of lower grades - the supplier i use carrys only one grade.

what do i use ? i prefer coosa,or divinycell when replacing a transom - nothing wrong with old school ply,as long as it's fully protected from water.both-meaning wood and composites,have their drawbacks - composites need to be thru bolted and sleeved - they fail to hold a screw.
composites break,they can suffer from delamination as well.
michigan composites make a core material similar to divinycell,however,it's much cheaper - i had a 29 sea swirl that struck a submerged object at a high rate of speed.the boat was only a few weeks old.the engines were almost torn off the boat - the transom core was broken from the impact - the impact was severe enough to shear the tilt piston - 4 stroke 250hp yamaha's,the tilt pistom is the one in the center - the outer 2 are the "trim" cylinders,the "tilt tube" was also broken,along with the clamps on both engines.composites are an amazing product.
as far as "doing a little research" is concerned,i do alot of reasearch every day -perhaps you would like to see a few of my research pictures ?
different products require different materials,as well as techniques - there's no substitute for real life experience,no substitue for formal training and certifications either...

my "research" comes from working with products every day - i can tell you what works and what doesn't,what's gonna fail and what's a half assed repair,or build...

 

[firecat1981]

again,only marine grade i've ever seen,or used is AA-no voids,no imperfections - "research" on the internet and actual experience are 2 very different things.personally,i'm not aware of lower grades - the supplier i use carrys only one grade.

Kreepa I'm not argueing that there are some plywoods that are better then others, or your experience with the types you use, but the above quote says it all. Just because you have never seen or used something doesn't mean it exists. You may have 1000 years of experience, but if it is all only with the same products from the same place then it's moot. If your supplier only carries one grade then they are charging you a premium for something that isn't needed. Why would you pay the extra money for AA sanded ply for a transom replacement that will be covered heavily in biaxial fabric and faired out? doesn't make sense since AA is mostly used for brightwork and would add a rediculous cost for a transom replacement.

Outside of that, you are wrong about composites. All composite means is being built from multiple materials and they have been building composite fiberglass boats since they invented fiberglass towards the end of world war II. Yes there are different composite cores you can use, but any coring is considered a composite. Also there are still many boat builders still cold moulding using plywood. Telling stories of big boats with big motors is impressive and that wreck sounds aweful, but this is microskiff. We are here to do more with less and the construction differences between small skiffs and big offshore boats is great!

I'm glad you are certified and trained, but so is any ASE mechanic and most I would never let touch my car or truck. I'm glad you have been working for 20 years, I'm sure you have seen some amazing boats and builds. I've met guys who have worked with glass for only a few months that knew much more then I did, and I've met guys who worked in a glass factory for most of there lives (actually this morning) that didn't even know the difference between epoxy and polyester resins. Point is with statements like something doesn't exist because I haven't seen it or used it doesn't lend well to asserting expertise.

PS. My ego isn't tied to an internet forum, so if you are going to try and knock my rig you had better come up with something better of your own more impressive to get a rise out of me

 

[jms]

again,only marine grade i've ever seen,or used is AA-no voids,no imperfections - "research" on the internet and actual experience are 2 very different things.personally,i'm not aware of lower grades - the supplier i use carrys only one grade.

Kreepa I'm not argueing that there are some plywoods that are better then others, or your experience with the types you use, but the above quote says it all. Just because you have never seen or used something doesn't mean it exists. You may have 1000 years of experience, but if it is all only with the same products from the same place then it's moot. If your supplier only carries one grade then they are charging you a premium for something that isn't needed. Why would you pay the extra money for AA sanded ply for a transom replacement that will be covered heavily in biaxial fabric and faired out? doesn't make sense since AA is mostly used for brightwork and would add a rediculous cost for a transom replacement.

Outside of that, you are wrong about composites. All composite means is being built from multiple materials and they have been building composite fiberglass boats since they invented fiberglass towards the end of world war II. Yes there are different composite cores you can use, but any coring is considered a composite. Also there are still many boat builders still cold moulding using plywood. Telling stories of big boats with big motors is impressive and that wreck sounds aweful, but this is microskiff. We are here to do more with less and the construction differences between small skiffs and big offshore boats is great!

I'm glad you are certified and trained, but so is any ASE mechanic and most I would never let touch my car or truck. I'm glad you have been working for 20 years, I'm sure you have seen some amazing boats and builds. I've met guys who have worked with glass for only a few months that knew much more then I did, and I've met guys who worked in a glass factory for most of there lives (actually this morning) that didn't even know the difference between epoxy and polyester resins. Point is with statements like something doesn't exist because I haven't seen it or used it doesn't lend well to asserting expertise.

PS. My ego isn't tied to an internet forum, so if you are going to try and knock my rig you had better come up with something better of your own more impressive to get a rise out of me

my ego's not tied to an internet forum either -
there's a reason to use aa fnished on both sides ply - reason being "adhesion" knots,imperfections,etc,these won't hold a lamination mix,unless filled - glassing over a knot hole ? there's gonna be a void - you really want a void ?
commons sense tells us,use the best materials,that way,no need to do the job again-again,there's different grades - but,the grade to use,is what i use,along with most guys in the biz i know -that grade is AA.attempting to laminate with warped,checked,split,full of imperfections,core material is asking for trouble -if that's what you use,and recomend perhaps you should reconsider your choices - using a core material like that is like assembling an engine with belt bolts...


"composite build" ,that refers to building with composites,not building with wood - hence the term "composite build"

"cored" fiberglass has been around since the beginning - using "composites" and "composite building",is the use of composite technology -getting away from the use of wood - wood rots,remember ? again,"composite" and "wood",are 2 very different things.building technology has changed dramitically,the use of composite cores,has almost become an industry standard
ever use composites ? vacum bagging techniques ? ever use these methods ? ever work with kevlar,carbon fiber ?
"internet research",and actualy using products is much different -kind of like going to the doctor's office ,you wouldn't go to a proctologist for a head ache,right ? but,they're both dr's ? right ? would you go to a heart dr fresh out of medical school,or would you go to a heart dr with a few years of experience ? i know my choice

operating a biz - you don't last very long,not knowing what you're doing,or using substandard materials - you're only as good as your last job

i realize this is "micor skiff",but,it's a boat - meaning,it gets wet,right ? same standards apply.use the best materials and techniques.there's an old saying "if you don't have the time to do it correctly,the first time,make time to do it again"

reason i'm home today - just got an epidoral in my lower back...

 

[cutrunner]

I understand why boats are now more composite and alot less wood but composite (foam) rots also..? Like kreepa said earlier if wood is completely "encased" it will last very very long, hence 40yr old bertrams that are still dry. Pursuit boat co still uses wood in certain spots in their boats. I think its the transom or stringers, cant remember which. Wood is also pound for pound stronger than steel. I also like how foam is lighter, but you cant secure/drill into it.its all give and take

 

[jms]

composites won't rot - they can become "delaminated",but,the product will not rot - very true,it will not hold screws - it's also recomended,a thru bolt be "sleeved" as well...there's pro's and cons of everything...with wood,it's all about protecting it from water intrusion - remember,fresh water rots wood,sea water actually "preserves" wood - fresh water in some cases,is actually harder on boats than sea water - i know,hard to believe,but true...
remember this when working with wood - the job is only as good as the foundation - using a n inferior grade of ply,with checking,splits,large knot holes,etc,isn't a very good foundation - using a polyester based resin with wood isn't the best approach either,due to it's being pourous,as well as only providing a "surface bond" only...

 

[firecat1981]

Kreepa composite cores as you listed is just the material, but any cored glass is called a composite. So yes plywood covered in glass is considered a composite build. Heres a reference look under wood
http://dictionary.sensagent.com/boat+building/en-en/

As far as using different types of materials in smaller boats, well here is where I learned most of what I needed for my first build. Jacue is one of the smartest guys I've had the pleasure of sitting down with, and one heck of a boat designer.
http://www.bateau2.com/howto/marine_ply.php

There is no point in us arguing this out because we have very different opinions on the subject, there are many who would support both of our sides and many examples of builds to support both as well, but we will never agree because we are in 2 different worlds. You are a guy who works in a shop with many resources and materials at hand, and I am a guy who is on a budget working out of his garage and with materials available to me. While I will agree it would be nice to use the most expensive materials all the time, it's just not practical for those of us who can't afford to run around in 40ft boats, or want to. To spend $120 for a sheet of marine ply and then buy a $80 epoxy kit, followed by $60 for a quart of paint all for just a rear seat cover on a boat that is only worth $500 (no offense MrSnook, just figure thats what a used highsider is worth around here) why? when you can do the job in a different material for 1/5 the price and it will last for decades if taken care of.

Anyway for the sake of the thread lets agree to disagree. Sorry to hear about you back and hopefully you will feel better soon.

PS I like the mini console on you J12, good luck with it.