Another plywood question - how much do I need?

[Kerry]

Hello - first post: I'm planning to build two Vardo kayaks for my wife and I, and I'm in the process of trying to find plywood for the frames.  I had thought I'd use 1/2" BB ply, but I've only been able to find it at one place so far, and it's not like the BB plywood I used to buy.  I guess this stuff is from China because I don't imagine Russian plywood is available at the moment.  The sheets I found locally have obvious voids (1/2" or so) at the edge, so I can only assume there would be voids or loose knots inside as well.  Strangely enough, the same place has 3/8" and 5/8" that look good, so maybe it's just a bad batch?  

 

There is a local place that sells Okoume marine plywood, but of course it's super expensive.  So what I'm wondering is - can I get two sets of frames and bow/stern pieces from one 4x8 sheet of Okoume, or would I be looking at needing two?  I do have a sheet of old (good) 3/8 BB on hand, and a sheet of 1/4" as well and I could perhaps double up pieces of the 1/4" for the stern and bow parts and only use the Okoume 1/2" for the frames if that would work.  

 

Thanks in advance for any advice.

[Scott Pettigrew]

For my Ravenswood LV it was half a sheet.  I also built a Vardo, but can't remember how much it needed.  

 

I used Roseburg 3/8 AB Sanded Marine-Grade Plywood from Menards, which looks like has really gone up in price too ..$100 for a 4x8.

 

I'm in the middle of the country, Okoume isn't available locally.  You'll gain a little weight savings with it if you decide to go that way.

[Kerry]

Thank you Scott, I appreciate it.  I just spoke to the place here that has the Okoume, and they only have 3/8" in stock, and aren't sure whether they're bringing in any 1/2" any time soon.  I feel a bit more confident in knowing the glue is waterproof, than the uncertainty I have right now around the Chinese stuff being passed off as BB, so I'll probably wind up going that way.  I suppose I could always laminate some thinner BB which I have onto what will be the weaker parts of the frames to add some strength, but I'm glad to hear your boat worked out well with 3/8" material.

 

Man, I wish I hadn't wasted all my BB stash on drawers and cabinets and such.  

 

Thanks again.

[Scott Pettigrew]

RacerX used 3/8 as well.  Seems plenty strong enough.

 

https://messing-about.com/forums/topic/13355-update-on-38-okoume-plywood-short-shot/

[Kudzu]

Sorry I missed your posting. There is so little activity here I don't check daily and it should have notified me of your post.

 

I can make one boat kit such as the VARDO from one 5x5 sheet of BB. It was the perfect size for boat kits. Very little scrap.  I never made them from 4x8 sheets. It wouldn't have been nearly as efficient for me trying to use large pieces of scrap.

 

I suspect that you will run a little short since a 4x8 sheet has  32 sq ft verses (2) 5x5 sheets having 50 sf ft. I just don't think you are squeeze two boats into that one sheet. It might fool me! But that is a big difference.

[Kerry]

Thanks Jeff.  Good to know.

 

Out of curiosity - have you purchased any of the new 'alternative' BB ply, supposedly from China?  Even though it costs far more than the old (Russian I presume) BB used to, it's still a lot cheaper than the Okoume plywood, but I really don't want to discover after building two boats that they use some inferior glue/plys.  Of course, what I can get here in Canada may well not be the same as what's available to you there.

[Kudzu]

No I have not bought any in a while. Trying to find someone to cut cuts kits and really concerned about what to use for plywood. I would probably go marine but I have to have it shipped in and freight shipping is not cheap. So not sure what we are going to do.

[Scott Pettigrew]

On 2/15/2025 at 10:10 AM, Kerry said:

Thanks Jeff.  Good to know.

 

Out of curiosity - have you purchased any of the new 'alternative' BB ply, supposedly from China?  Even though it costs far more than the old (Russian I presume) BB used to, it's still a lot cheaper than the Okoume plywood, but I really don't want to discover after building two boats that they use some inferior glue/plys.  Of course, what I can get here in Canada may well not be the same as what's available to you there.

Buy the smallest sheet of plywood available and soak a small piece in water for 24 hrs.  You can also boil it for an hour. If it doesn't delaminate it will be OK

[Kerry]

10 hours ago, Scott Pettigrew said:

Buy the smallest sheet of plywood available and soak a small piece in water for 24 hrs.  You can also boil it for an hour. If it doesn't delaminate it will be OK

Thanks again.  

[Kerry]

Finally getting back to this project.  A couple of days ago I went back to the store I was at earlier with the less than stellar looking BB to buy a sheet and put a little in water to see what happens.  The sheets they had this time looked much better than what I'd seen earlier, with no voids visible in the sides.  Honestly, it looked like the same quality of BB we used to get (although a darn site more expensive!).  I bought 2 sheets and yesterday cut off a small corner to soak in water for 24hrs, and it still looks fine.  No sign of delamination at all.  Looks like I'm back in business!