Question on plywood and other Matl's.

[saltfly]

Ok I’ve used marine plywood on a number of projects and when properly encapsulated, I’ve never had a problem. But what have others used, when it comes to wood, not any of the foams? A friend who is in the fiberglass repair bis. Suggested Okuame. It looks good and I’m hearing nothing but good about it. But it is costly. Has anyone ever used any of the man made lumbers and if so, how good does fiberglass hold to it? I’m planning a number of projects and cost will enter in to it, since I have so many to do. So I’m trying to plan a head.

[gran398]

My builder, Seamark Boats, uses AC fir plywood on everything. Transoms, stringers, decks.

My build is the first all synthetic boat they've ever done.

[fishinonthebrain]

Saltfly I know you have been involved in my project and I know i don't need to mention how much work it is but to me I never want to do the same things over so no wood for me. It will cost some more but you won't have to replace it again.

Coosa and nidacore.

[gran398]

Saltfly I know you have been involved in my project and I know i don't need to mention how much work it is but to me I never want to do the same things over so no wood for me. It will cost some more but you won't have to replace it again.

Coosa and nidacore.

That was my thinking too. Even if the deck screws leak down the road...there is nothing to rot.

In theory....these boats could go a LONG time.

[Capt. Bob]

Saltfly I know you have been involved in my project and I know i don't need to mention how much work it is but to me I never want to do the same things over so no wood for me. It will cost some more but you won't have to replace it again.

Coosa and nidacore.

That was my thinking too. Even if the deck screws leak down the road...there is nothing to rot.

In theory....these boats could go a LONG time.

I'd wonder what happens as these space age materials retain water through penatration. Does it alter their original fabrication and how does it affect (if any) their structural stability e.g. shape/strength.
They may not rot but maybe they get "soft"/separate.

Goggled Nicacore. Interesting
http://nida-core.com/english/nidaprod_h ... _rigid.php

[gran398]

Saltfly I know you have been involved in my project and I know i don't need to mention how much work it is but to me I never want to do the same things over so no wood for me. It will cost some more but you won't have to replace it again.

Coosa and nidacore.

That was my thinking too. Even if the deck screws leak down the road...there is nothing to rot.

In theory....these boats could go a LONG time.

I'd wonder what happens as these space age materials slowly absorb water. Does it alter their original fabrication and how does it affect (if any) their structural stability e.g. shape/strength.
They may not rot but maybe they get "soft".

Goggled Nicacore. Interesting
http://nida-core.com/english/nidaprod_h ... _rigid.php

That's true Bob. The water must go somewhere.

Whether it get soft or not, with age, good question.

Interesting commentary on their website, tx for the link.

[seabob4]

The key, with any type of coring material or foam used as flotation or stringer "filling" is to keep it away from water.  Period.  Whether it be PT ply, fir, end-grain balsa, nida-core, divinylcell, coosa, coremat, you name it.  While all the composites can claim a "no rot" attribute, and most will absorb such a small volume of water that it is almost negligeble, it still behooves the builder, or re-builder, to do his best to keep water intrusion into the cored areas to a minimum, optimally, to no intrusion at all.

With proper installation techniques, proper care, and taking ones time to do it right, all the above materials will last years and years with no degradation in the boats structure, as well as minimum weight gain due to accumulated water as well at saturated materials.

One of the biggest issues with foam filled stringers is not the fact that eventually the foam gets saturated, but HOW it got saturated.  The method of installation of a foam filled stringer grid is as such.  The hollow grid is tabbed into the proper location in the hull.  2-part foam (usually a BASF Isocyanate) is "shot" into the grid, hopefully filling all the grid.  "Foam holes" are drilled at various areas on top of the stringers to allow excess foam to expand out, or else the stringers would burst due to foam expansion.  Here's where the problem starts.  One the foam has kicked off, the excess foam is shaved off, LEAVING MANY THOUSANDS OF OPEN CELLS TO ABSORB WATER.  Most often, these holes are either covered with plugs secured with 5200, or are simply painted with gel coat, a permeable membrane.  The second real issue stems from the weep holes that are drilled at the base of the stringers to allow compartments within the grid to drain.  Most commonly, all that is done to the exposed foam is once again to paint with gel coat...just a step above from doing nothing.

So now you have water sitting in these compartments because the weep holes are a little too high, yet just low enough that water can continually come in contact with the gel coat that "protects" the foam...and over time, absorbtion occurs.

So it really comes down to proper installation and technique more so than choice of materials...IMO.

[wingtime]

I used okuame to rebuild my fuel tank lid.  It seemed pretty good, but I sold the boat so I cant tell you how long it lasts!

[saltfly]

Capt. Bob my thoughts exactly. The state I was originally froms DNR. Had problems with their Boston Whaler Outrages. They where gaining weight and finding the hull separating from the foam. The problem was the foam used in their hulls. It is only suppose to have a 1 percent moister absorption rate. That is a bench test number and doesn‘t factor in the real world. So they dumped a number of boats and replaced them with new ones. Which started gain weight after only 6 mons. of use. I bought one of the outcast boats. I found what was happening to them and removed the problem parts. It rained, as I put it under that boat for two weeks. After that the boat was taken back to the scales and weighted. It came in at the shipped weight. It lost 235 lbs. of water that was in the foam. A friend who worked for DNR told  Jim D that a friend of his found the problem.  He called and I told him what the problem was. The guys from BW said that couldn’t happen. I showed them how it did happen. They and the state changed how they did one assembly procedure. And their hasn’t been a problem since. So in the really world of matl. usage, you know the answer. S**t happens. I’ve always gone by the fact if it can happen it will. Besides, I’m 66. Just how many years do I need something to last. These boats have been around along time and still going. I’m sure they will be here longer then me. In fact I know they will. bwahahaha

Wing the friend that is a fiberglass guy, who told me about okuame. Has a piece of it sitting outside of his shop, and it has been sitting their for 2 years and has no rot. But you have to remember , air can circulate around it and dry it out. But he loves the stuff.

Bob your on the money as well. Proper assembly, solves a lot of problems.

And fish, with the job you are doing. Your not going to have any problems at all.

[Capt. Bob]

The upside for me is that no matter what I might use, if I do it even half right, I'll be dead and gone before it needs redoing.    

And who says old age doesn't have its benefits.

As SB states, the proper encapsulation of whatever coring material you use is the foundation and penetration sealing the key.
My wife has commented many times on my loss of structural integrity to which I lay blame on poor encapsulation from the factory.

"Encapsulation my butt. Try excess inebriation". Therefore I try not to spill too much "bug juice" on the deck.

She makes a strong point in that the deck of my 91 is stiffer than me. :(

[saltfly]

 

[gran398]

I did mention something about "get soft with age" but I did not have the kahunies to carry forward with the next thought set.

However, I have now been inspired by a higher power so....

"But hey, they have medication for that."

[saltfly]

Hey Gran, have you ever seen Jeff Durhams, puppet Walter. ( my wife swears he modeled him afterme) You don’t need them Just the age.

Now back to the wood. No pun intended. I may go with well encapsulated A-C fur for nonstructural areas. And either okuame or marine plywood for structural areas. But I would still like to hear from some others some maybe in the bis, that are on the board, hu, maybe, yea??????? I hope so.

[gran398]

Salt, thanks!

Seamark doesn't use marine ply due to the moisture content. He is tickled pink with the AC fir, everywhere. It is very strong....and pretty darn impressive.

If you are cool on not making a decision within the next couple days....hang loose, I'm going out there this week.

He's working on a new one right now. I'll take some pics and post up right here.

Thanks

[shortpants]

A friend of mine who is a boat builder told me once that if there were any one perfect material to build boats with he'd be able to build the perfect boat and if that were the case, he'd be a rich man!  He put the transom in mine after I got it a few years ago before the rebuild process of the rebuild from that guy in Tampa  :x , and we discussed that the wood in the transom had been in there for 36 years so, put wood right back in it.  My feelings were what Bob said, I will be dead and gone before I hope to have to replace it again.

What is amazing is that everyone has varying opinions as which material should or shouldn't be used.  I found when inquiring about putting another deck down recently going from shop to shop is that what one shop would use another wouldn't.  They all may not have really talked bad about the other product they just felt that what they were using was superior then the other.