Question about Marine grade plywood for boat building?

CAnderson

Well-known member
So I reading through a recently acquired set of plans from Devlin. I have started looking around locally for Marine grade plywood. I found a couple of places to get the wood and that claim to stock it regularly. One place I call, they have Marine AA grade plywood. Another place, that is cheaper but also much closer, has Marine AB that is supposedly Douglas Fir. When I asked the owner about the difference between Marine AA and Marine AB, he told me he never heard of AA. He only knew of AB. I then asked about BS1088. He again said that he didn't know what that meant and as far as he was concerned, the best and only grade of Marine ply was the AB that he carried.

So, can anyone clarify this for me? I assume they (AA and AB) are in fact two different grades and that the AA is a superior grade to the AB. Is that correct? Where would the BS1088 fall into this argument?

Thanks in advance.
 
ok 1088 is marine plywood produced with untreated tropical hardwood veneers try going to marine plywood at boat builder central they have some excellent advice on marine plywood hope this helps
 
So I reading through a recently acquired set of plans from Devlin. I have started looking around locally for Marine grade plywood. I found a couple of places to get the wood and that claim to stock it regularly. One place I call, they have Marine AA grade plywood. Another place, that is cheaper but also much closer, has Marine AB that is supposedly Douglas Fir. When I asked the owner about the difference between Marine AA and Marine AB, he told me he never heard of AA. He only knew of AB. I then asked about BS1088. He again said that he didn't know what that meant and as far as he was concerned, the best and only grade of Marine ply was the AB that he carried.

So, can anyone clarify this for me? I assume they (AA and AB) are in fact two different grades and that the AA is a superior grade to the AB. Is that correct? Where would the BS1088 fall into this argument?

Thanks in advance.


The AA and AB is the quality fo the face plys - the only marine ply that I've seen sold listed as "AA" or "AB" is marine doug fir. The "BS" classification of 6566 or 1088 is what you want and is tropical hardwoods, like okoume or meranti. Devlin says not to use marine doug fir in his boats and in his book says to use okoume. In conversations with him in recent years he has been suggesting meranti as a good alternative to okoume. So, you will probably have to special order something, which is not a big deal. Have it shipped freight and pick it up at your local depot (which cuts down on delivery fees).

T
 
I use Condon lumber in westchester NY. They have been in business for years and know the business. I use them for specialty woods. I would call them and ask questions and go from there. Good people.
 
Todd, I started pricing out some online suppliers. There is abig descrepency in price between the "marine AA and AB" fir that I was quoted locally and what the Okuome and Meranti are going for. I will have to check in on shipping rates.

Although I wouldn't mind a drive to MD or NY to kill two pipes with one stone and have a nice day trip on a Saturday.
 
Wendell, my thoughts exactly, which is why I started asking the question here. The guy at the local yard I called sounded like a good old guy that has been in the business for quite some time. But when I started asking questions and he hadn't heard of okoume, Meranti, bs1088', and couldn't tell me how many plus were in the plywood he was trying to sell me. I figurd I better politely move onto another wood source.
 
Todd, I started pricing out some online suppliers. There is abig descrepency in price between the "marine AA and AB" fir that I was quoted locally and what the Okuome and Meranti are going for. I will have to check in on shipping rates.

Although I wouldn't mind a drive to MD or NY to kill two pipes with one stone and have a nice day trip on a Saturday.


If you haven't worked with it before, you are going to be astounded by how nice the BS 6566 and BS1088, it is a dream to work with.

T
 
I believe I used it one time before. A friend had a 6x10 utility trailer. He wanted me to build wood sides for the trailer that were 4' tall. At the time he specified using okoume for the trailer because he was able to get it in 10' long pieces. He paid for it and I built it. I now own the trailer. After almost 10 years of use and some very good spar varnish, the plywood is still in excellent shape without any delamination.
 
Wendell, my thoughts exactly, which is why I started asking the question here. The guy at the local yard I called sounded like a good old guy that has been in the business for quite some time. But when I started asking questions and he hadn't heard of okoume, Meranti, bs1088', and couldn't tell me how many plus were in the plywood he was trying to sell me. I figurd I better politely move onto another wood source.

The "BS" is for British Standards and is associated with Loyds Register which is a maritime risk management group NOT Loyds of London which is a group of insurers in London which becomes a bit confusing. While I lived in Florida I meet a guy that builds boats. He told me he uses only marine grade which carries the mark "BS1088" for insurance purposes. Apparently it's easier to get insurance on a wooden boat that can prove it's constructed with this wood because it has a higher standard of testing. What do I know, it may be all smoke up the skirt but he sure believed what he was telling me. Great sales pitch anyway.

I read a disturbing story about a guy who built his ex-wife a day sailer out of Luan. If you consider other than marine grade consider where you'll ever use your boat!
 
All~

Great thread - I agree completely re using Marine Grade for the hull. It is structurally critical because the standard requires no voids in the interior plies. However, I have used AC for decks and bulkheads - mostly because I am now far from any vendor for Marine ply - but the likelihood of failure is also pretty low for these applications. And, I get a good quality AC from my local (family-owned) lumberyard. I cover it with marine epoxy resin and 6-oz cloth and have always had good performance/durability.

The lauan plywoods I have seen are fine for underlayment or cabinet backs or drawer bottoms or other non-critical, non-boat applications.

All the best,

SJS
 
All~

Great thread - I agree completely re using Marine Grade for the hull. It is structurally critical because the standard requires no voids in the interior plies. However, I have used AC for decks and bulkheads - mostly because I am now far from any vendor for Marine ply - but the likelihood of failure is also pretty low for these applications. And, I get a good quality AC from my local (family-owned) lumberyard. I cover it with marine epoxy resin and 6-oz cloth and have always had good performance/durability.

The lauan plywoods I have seen are fine for underlayment or cabinet backs or drawer bottoms or other non-critical, non-boat applications.

All the best,

SJS


I'm fine with a compromise approach on some designs, but on the Devlin boats the bulkheads are structurally critical given the nature of the design, and the designer specifically states do not use marine doug fir.

If someone is ordering quality wood for hull and bulkheads, I'd go ahead and suggest that they order the same quality stuff for the decks too.
 
I don't know what your name is. On this sight we generally maintain a first/full name basis. What Devlin design are you building?

About plywood:

Forty years ago marine fir plywood was the world standard. It was made from rotary cut veneers from old growth trees. AA was the best grade and usually consisted of every ply made from one veneer. It allowed for multiple veneers for the inner plys and a few small knots (usually replaced with footballs). No voids were allowed. AB merely allowed for multiple veneers per ply internally and on the "B" face. The problems with marine fir plywood is that the quality of the trees cut nowdays isn't what it used to be, i.e., second growth. Also rotary-cut fir plywood will check if not fiberglassed on both sides. It is also stiffer (doesn't bend as well) and heavier than Okoume.

British 1088 and 6566 are standards to which marine plywoods are constructed and are also a little species related. 1088 is the highest standard and requires not delaminating even when boiled in water.

Okoume is the benchmark marine plywood in many ways. It is the lightest, bends better than any other. It is perishable, more so than Sapele, Fir, Luann and Khaya and must be thoroughly epoxy encapsulated.

Twenty-three years ago I built a Devlin Black Brant from Bruynzeel Okoume plywood I purchased from Harbor Sales in Baltimore, MD. I see that they are now in Sudlersville, MD. As close as they are to you I would call them. By picking it up yourself you would offset some costs over packaging and shipping.

http://www.harborsales.net/

My $0.02
 
Jeff- Thanks for the reply. I am reading over the plans for the Devlin Sculldugery II. While it is the primary boat I am concerned with at this time, I have two layout conversions that I am heading towards as well. Figured I would use the layout conversions to "get my feet wet" and then after a little trial/error and learning from those, I would tackle the Sculldugery.

I called Harbor Sales in MD and was quoted a price for Marine Grade AA fir. Not that I specifically asked for Okoume or Meranti. My choice would be the Okoume for the savings of weight especially. I will call them back today to inquire about the availability of Okoume plywood. I read elsewhere that they may not carry it any longer.
 
Tod et al~

I lost the premise that this was a Devlin design. I would use nothing but good Marine for any of his boats - mostly because they are worth it. I use AC for bulkheads only when converting 'glass hulls into duckboats.

Did not mean to run the thread off the rails....

SJS
 
Tod et al~

I lost the premise that this was a Devlin design. I would use nothing but good Marine for any of his boats - mostly because they are worth it. I use AC for bulkheads only when converting 'glass hulls into duckboats.

Did not mean to run the thread off the rails....

SJS


Steve, I don't have any concerns about yours or anyone's intentions in this thread (except that jeff smith guy, his intentions are always suspect). :).

It is just that we have found that over the years there is such a strong urge for people to use inferior wood on stitch and glue boats that any comment in a thread that says something else is OK will resurface as an endorsement of inferior wood. I was perfectly clear on your purpose for ACX, I just had to make it double perfectly clear, not for anyone in this thread, but for "that guy" that reads it and puts 2 and 2 together and gets 3 and says ACX is good for Devlin boats.

As for the original purpose of the thread, it seems like Chris is on the right track.

T
 
Steve-

The layout boat conversions that I speak of are the Sunfish boats that we spoke of. The "big" boat project as mentioned is the Sculldugery II. We have been looking at many plans for boats trying to determine what we will build. Since we have been looking more into giving sculling a try, we started looking at various scull float designs. When my son saw the Sculldugery II floating in the water, his eyes lit up and I knew this was the boat we would give a try.

I called Harbor Sales back. This time I specifically requested Okoume marine ply and then asked if it was stamped BS-1088. They do have Okoume, it is stamped BS-1088 and they can ship to my door the next day at a very reasonable price! (still expensive, but much more reasonable than some other places I have looked.)
 
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