1088 vs. 6566

[Arko]

What are the differences between the two. I mean if guys are out there building S&G designs from luan and ACX and some with BCX, surely the 6566 Meranti or Okoume is worth the money. The only difference I have been able to distinguish from specs on some sites is the thickness of the face veneers. One millimeter vs. 1.5 millimeters.
I have read about more than a few folks building Bateau designs using ACX and other X grades.
I just can not bring myself to cough up the dough for 1088 Okoume. What is wrong with the 6566 that no one uses it. Noahs has it at a great price. I am needing 25 sheets of ply so I am trying to find the most viable alternative to the very pricey Okoume 1088.
Some opinions would be greatly appreciated.
I am going to build Jacques Mertens LB22 design. That is that most beautiful little lobster boat he has on his site. It is not a planing hull as you can see. I know I need to use the best materials I can afford but that 1088 stuff is out there.
I have heard the " It's only a small percentage of the total cost " point of view and the " Buy the best you can afford " point of view. What I want to know is whether this 6566 is suitable for S&G construction of a small displacement hull that will probably see a fairly " pampered " life, be well maintained and be stored indoors.
I would think the LLoyds of London approved 6566 would also be better than Marine Tech or Aqua Tek plys which are not LoL approved ( are they??? ) and most assuredly better than ACX or Luan.
If I am correct in my view why does no one expound the attributes of the other Loyds approved wood, 6566?
If I am going to buy any peice of mind in not having a bunch of hidden voids or having the correct glues and maybe have the option of doing some brightwork, I think the best I could afford WOULD be the Meranti 6566.
Like I said before, any insight would be appreciated. Thanks

[Not A Guest]

The various standards Loyd's 1088 and 6566 or the APA's marine and AAX down to DDX are simply standards that "guarantee" certain properties.

Unless you did the engineering for the boat you are building you have no way of knowing what properties limit the design and no way to know which of the standards you should insist upon.

If you are using plywood for spacing between FRP faces than any plywood is sufficient, a lot of foams are also sufficient. If you are relying on the plywood to supply support for motors or to provide hull strength, the higher grades will provide more strength. Trailer sailing may tolerate more voids in the plywoods than docked sailing.

You might ask the boat designer.

[TheFisher]

ARKO,

Why don't you use what Jacque recommends? He is the designer and if you have questions, ask him directly. I have seen your posts at his site so I know you are aware of it. As for the plywood, here is a qoute from the LB22 page:

The BOM list materials based on our standard layout and includes a 15% waste factor for fiberglass. For plywood, we use standard sheets 4' x 8' (122 x 244 cm). Please read the building notes and see the plans for detailed specifications. Marine Tech or XL boat building plywood is an inexpensive type of marine ply ideal for stitch and glue construction. It cost, on the average, less than $20.00 a sheet in 1/4" (6 mm). Okume or Meranti marine can also be used and cost starts at less than $40.00 a sheet (1/4"). Good quality exterior is acceptable if it has no voids.

Our recommendation is to use at least marine ply for the outside parts. The inside can be made from quality exterior with no voids.

There is your answer as to what plywood is acceptable for the LB22. Okume and / or Meranti DO NOT have to be used.

[Arko]

Originally Posted by TheFisher

ARKO,

Why don't you use what Jacque recommends? He is the designer and if you have questions, ask him directly. I have seen your posts at his site so I know you are aware of it. As for the plywood, here is a qoute from the LB22 page:




There is your answer as to what plywood is acceptable for the LB22. Okume and / or Meranti DO NOT have to be used.

The thrust of my question was simply about the difference between the 1088 standard and the 6566 standard. I know it would work for this and most others. Same wood, same glue, same number of plys. I think Bateau used to even use 6566 ( I think ). I just wanted to know what the difference was in the two standards and why no one seems to use it.

[TheFisher]

Arko,

I apologize for my misreading of your question.

I humbly submit a short answer to your question:

BS1088 is made from Okoume and is of the highest quality with a defect free core and both faces of solid A surface while BS6566 standard is less species specific and is more permissive so the surface of this plywood may show a few skin defects on one or both faces.

Here is a link to get more info.

http://www.oneoceankayaks.com/stitch...m/plytype1.htm

Most people do not use it because of the thinner face ply as that is where the FRP and wood bond is located. You want a heavier ply most of the time in order to prevent a bonding failure. Additionally, leeser quality species are permitted in the interior plies which results in lower strength characteristics for the plywood.

By judiciously (sp?) selecting the proper types of plywood for the usage, you can keep you overall cost down while getting the most from your materials. You can use 1088 for the hull exterior, marine tech for other items such as framing and decking, and 6566 for bright work that is not under a lot of stress. This will give you the best of all the properties at a cost that will be less than using all of one type.

Alternatively you can use 6566 for the hull and marine tech for the remainder of the hull except for your bright work. Or just Marine ply and limit the 6566 for your bright work.

People have a tendency to want to use the best. Most amatuer builders will do this to compensate for not being confident of their build even if it is not justified and results in lesser performance.


I don't have an answer as to why everyone pushes 1088 over 6566. I have a few ideas but nothing definitive. In some cases 1088 is specified. Where it is not 6566 is more than adequate.

[Arko]

Originally Posted by TheFisher

Arko,

I apologize for my misreading of your question.

I humbly submit a short answer to your question:



Here is a link to get more info.

http://www.oneoceankayaks.com/stitch...m/plytype1.htm

Most people do not use it because of the thinner face ply as that is where the FRP and wood bond is located. You want a heavier ply most of the time in order to prevent a bonding failure. Additionally, leeser quality species are permitted in the interior plies which results in lower strength characteristics for the plywood.

By judiciously (sp?) selecting the proper types of plywood for the usage, you can keep you overall cost down while getting the most from your materials. You can use 1088 for the hull exterior, marine tech for other items such as framing and decking, and 6566 for bright work that is not under a lot of stress. This will give you the best of all the properties at a cost that will be less than using all of one type.

Alternatively you can use 6566 for the hull and marine tech for the remainder of the hull except for your bright work. Or just Marine ply and limit the 6566 for your bright work.

People have a tendency to want to use the best. Most amatuer builders will do this to compensate for not being confident of their build even if it is not justified and results in lesser performance.


I don't have an answer as to why everyone pushes 1088 over 6566. I have a few ideas but nothing definitive. In some cases 1088 is specified. Where it is not 6566 is more than adequate.

No worries.

[Troutlet]

Arko,
I'm not sure if your question is due to cost or not but I thought it might help to know how I chose.
I searched all over the web for cheap marine grade plywood as well as 3 local stores. I lalso ooked for the Marine-tech, mentioned in Jacques descriptions. I found one local dealer for Marine-tech but the prices were just as high as 'the good stuff'. Bottom line, it was all EXPENSIVE. I ended up finding Meranti BS6566 from Noah's website. It was the cheapest route that I could find.
I then told Jacques and friends about the deal and he matched the price AND gave me Meranti BS1088. Plus it was delivered in three days instead of two weeks for Noah's or my local lumber yards.
Since your building one of his designs, I suggest that you find your best deal on any type of marine grade plywood and then try his price guarantee. Worked for me!