plywood question

[Axkiker]

Not trying to take anything away from your Advantech, but...

Advantech is classified as Exposure 1 grade for moisture resistance, from their site:

Pretty much the same as most plywood, even the stuff we call Exterior grade which really isn't true exterior panels.

When they say Advantech is stronger than plywood they're only comparing it to 4 ply plywood which is about the same as 3 ply. 5 ply plywood is stronger and that's what most 3/4" plywood is and the better 1/2" is.

I cant quote what exposure rating Advantech is etc. Like I said i'm a rookie with no scientific backing. When I purchased my material I did so based a lot on the information provided in the link below.

http://www.huberwood.com/advantech/performance/moisture

They give some charts regarding the moisture absorption rate of Advantech VS other osb or plywoods. The chart which lists the rate of absorption and the test they provide with red dye did it for me. Plus when I called around about having the inside LineX'ed they suggested advantech.

All I can say is it seems much stiffer and heavier than the comparable 3/4 ply I have laying around. Maybe ill try some additional tests... Anyone have suggestions on tests they would like to see. I have it so I may as well test.

 

[bonz_d]

This is only a 16' aluminum fishing boat with a limited weight capacity, The idea is to reduce weight which is why I'm sure Alumacraft built this while only using 1/2" decking and the number of stringers under it for support. So yeah, anything added from the original design needs to be deducted from the capacity weight, like trollomg motors, batteries, fuel tanks, heavier decking boards.

 

[jbcurt00]

Hmmmm, I've never seen heard anyone say that Nautolex could be torn or have a hole worn thru it, let alone HAS a tear or a hole.

IMO, properly done plywood covered w properly done vinyl will outlast the same plywood covered w properly done carpet.

JIG:

• How long has your Nautolex vinyl been installed?
• How often do you use your rig?
• How rough are you on the Nautolex??

I suspect it's been down for a few years, you use it FREQUENTLY and you don't treat it w/ kid's gloves. W/ the epoxy coated plywood decking wrapped w/ vinyl, I think it'll last for a very, very, very long time. Right?

 

[bonz_d]

Though I have never used it I have seen it and know what it is. I would think that any wood properly covered with it would outlast carpet. By the time you apply the adhesive, which I'm assuming gets put down like carpet adhesive with a notched trowl, but it down and roll it out with a vinyl roller I would think an epoxy coating under it would not be needed accept for the edges and any exposed wood. Water will not penetrate vinyl flooring very easily.

I had concidered putting carpet back down on the decking until I started to remove what was left under the livewell, rod locker and flotation boxes. In this case the hull seems to have been constructed with the decking layed 1st, then carpet, then everything above the decking. The flotation boxes had the foam poured in over the top of the carpet as was the livewell.. The carpet and plywood under those areas is complete mush! As I am sure those areas never had a chance to dry once they became wet.

The Lund I had done previously I had done with carpet. It is still as good as the day I put it down, no lifting anywhere. I also is done in a way that it dries out very quickly and has no areas that are covered by other structures. That job is now about 6 years old.










I will probably recover those areas that are still carpeted with new carpet. As you can see that even though that carpet is now 26 years old, though dirty is still in good condition.

 

[fishrdan]

What are you going to protect the plywood with, epoxy, varnish, paint, chemical treating? If the raw plywood isn't protected, it's going to rot quicker than if it's protected.

At a minimum, I would soak the wood with Jacso Termin-8 waterborne or Tim-Bor boiled up with water. This will give the wood some mold-rot resistance. Not as good as epoxy sealing, but better than nothing.

(The cheapest.... Get a box of 20 Mule Team Borax laundry additive from the grocery store, boil with water to dissolve and soak plywood in solution.)

 

[bonz_d]

What are you going to protect the plywood with, epoxy, varnish, paint, chemical treating? .)

Don't know yet, haven't gotten that far. The Lund I did just used spar on it and it's held up well.
Now what makes you think I wasn't going to treat the wood with something?

 

[jigngrub]

JIG:

• How long has your Nautolex vinyl been installed?
• How often do you use your rig?
• How rough are you on the Nautolex??

I suspect it's been down for a few years, you use it FREQUENTLY and you don't treat it w/ kid's gloves. W/ the epoxy coated plywood decking wrapped w/ vinyl, I think it'll last for a very, very, very long time. Right?

Nautolex has been installed nearly 3 yrs. now

Rig is used weekly Oct-May.

I'm probably rougher than a lot of folks on my vinyl. I have a bad habit of making Crappie structures and taking them out and sinking them in the lakes I fish.

My fish structures are made of block, concrete, plywood, brush, and bamboo... and they're heavy 70-90 lbs. each and have sharp corners and stuff:





Not the first hole, rip, or tear in my vinyl from this or any other abuse I dish out on my vinyl.

One of the things about sealing the plywood with epoxy resin is that it not only seals the plywood, it also hardens the surface of the wood. This is added protection to the wood and the vinyl. Object are less likely to poke through the vinyl and into the plywood because the plywood was soft under the vinyl.

Another thing about the epoxy is that it's a secure bond to the plywood, the vinyl and glue are only going to be as secure as what they're bound to.

About the adhesive for the vinyl, I suggest and thin brushable or sprayable adhesive... I prefer the Weldwood contact cement brushed on. You get lots of working time with this material and it's a positive immediate bond that's very water resistant. If a troweled adhesive is used I suggest a solvent based material applied with a 1/16" or less notched trowel. There was a vinyl decking installation fail on this forum that used a troweled on adhesive and I think the fail was caused by excessive off-gassing of the adhesive:
http://forums.iboats.com/forum/boat...22-starcraft-supersport-v5-restoration/page60

This is just my experience and thoughts, your mileage may vary and objects may be closer than they appear.

 

[UConnMRB]

Not to thread hijack, but Jig, what are those things for? I am not a fisher ( I enjoy it but dont do it alot), but do you sink those so the fish have somewhere to gravitate towards?

 

[jigngrub]

but do you sink those so the fish have somewhere to gravitate towards?

Exactly, well call it habitat.

 

[Woodonglass]

Bonz_d, I'm NOT a TinCan Man but...Decks are decks in a boat and structural integrity is basically the same and I do know a few things about that soooo based on that I'd be curios to know about the undercarriage of your boat. What is your deck supported by and what is the span between the supports? Weight is a BIG consideration anytime your replacing things in a boat or a plane. Light is right!!! As long as it's STRONG AND waterproof. Lots of different methods to make it waterproof. Some better than others. Some more pricey than others. All depends on how far you wanna go with it. Bottom line to the whole deal is it's your boat and your project sooo You need to make the decision and go with it. As long as it's basically safe and your satisfied, it doesn't really matter what we think or say. Especially ME!!! I'm just an AND a Glasser to Boot!!:facepalm:

 

[bonz_d]

OK, Stringers run bow to stern. 10" centers with a 1.75" flat flange on the top and there are 5 stringers. If you look at the pictures I'd posted there is 45" between the livewell and rod locker. Right now it has 5/8" ply covering it. Which was done very poorly. Looks as if the old deck was cut off flush with the 2 boxes and then just butted up against the boxes and the old wet rotting plywood was left under both boxes. The plywood that I was able to get out from inder the rod locker is 1/2" 5ply.
Which is most likely what I am going to replace it with.

I'd post uo a picture of the uncovered stringers but like a DO MO i unknowingly left the camera out on the boat last night and of course we had a downpour this morning. Screen on camera is all fogged at the monent so I'm not turning it on yet.

 

[Woodonglass]

Sorry to hear about the Camera! I've NEVER done any Stupid Things!!!! Uhmmmm well, maybe Once!!!! or Twice, or Three or....:facepalm: Well here's my advice for whatever it's worth anyway. Take some 1/2" ext grade plywood and lay a couple of 2x4" on your driveway @ 10" on center then place the plywood on top. Then walk on it and see what you think. I'm bettin you'll find it to be plenty strong with little flex. When it's attached to the stringers it'll be even more stable and less likely to flex. If you seal it well with what ever method you choose to use, it should last a long time. The key to longevity is always good care and maintenance. Do that, and she'll give you good service and last a good long time!!

 

[jigngrub]

Put that camera in a zip-loc bag with a couple cups of dry white rice.

 

[bonz_d]

Thanks wood! I think I have to agree with your assessment otherwise I don't think Alumacraft would have built it that way originally. Actually 3 of the 4 spaces on the top of the stringers has an openning of only 8.25" and the other one is 10" Because the top of the center stringer is flanged to the starboard side as are the other 2 while the 2 stringers on the port side the flange goes to port.

Right now I'm considering using your boiled linseed recipe to treat the plywood.

 

[bonz_d]

Put that camera in a zip-loc bag with a couple cups of dry white rice.

Got that covered! Will give it a day or two and see what happens. But I do have faith!!!!!

 

[jigngrub]

Right now I'm considering using your boiled linseed recipe to treat the plywood.

Carpet/vinyl adhesive ought to stick to that better than anything eh?!

 

[Woodonglass]

Make sure to read the recipe thoroughly. You let it dry for 2 days and then finish it by coating with 3-4 coats of full strength Marine Varnish. Your glue will stick to that with No Problems whatsoever. Your plywood should look almost like a hardwood floor when you're done. the sealer penetrates deep into the pores of the wood to seal it and the Varnish encapsullates it similar to resin. Just a lot cheaper. It's NOT as durable as Poly or Epoxy and I've never said it was. It's just a less expensive alternative but it IS a very effective and proven water resistant sealer for wood. As I've stated many times proper care and Maintenance will extend the life of anything. If you end up using it Take some pics so everyone can see what you end up with.

 

[bonz_d]

Here they are, a couple pixs of the stringers where I removed the plywood.





The bottom picture shows a pcs of the old carpet that was left when th PO redid the decking. That is also a part of this where I will need to slip the plywood under and into that gap. That structure is a flotation box.

 

[Woodonglass]

Yeah with that narrow span and with the added foam support...1/2" ext. Ply will be more than adequate IMHO. But again, It's YOUR boat and you should do what makes sense to you and what you're comfortable with.

 

[bonz_d]

Don't know yet if I'll ever truely be comfortable in this decision BUT I do know that Alumacraft sold a lot of these boats over many years with the same material and it also was not expoy coated. I have also looked at a good number of these same boats with the original decks in them and they are quite sturdy.
I also emailed Alumacraft CS a few weeks ago about this to try and find what was actually used when they built these boats but as of yet I haven't received any response. Don't expect I will either.