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First Post - CS17 - New Build - Problems already?


mattp
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Hello forum,

An old friend and I are starting a joint venture build of a CS17. I have dabbled in boat building for the last couple of years mostly using cheapo Lowes-Depot materials. I feel that the CS17 is the kind of boat that should last a while and deserves good materials.

So today we take delivery (delivery because we are several hours from anyone that would recognize the phrase "marine plywood") of the required 1/4 and 3/8 plywood in BS1088 Okoume. Here's the problem, or so I think. I've wasted enough hours lurking in boat building forums to know that the best 1/4 Okoume has 5 equal thickness plies. This stuff has 5 plys but the outer veneers and inner most ply are considerably thinner than the other two. How concerned should I be about this?

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Very.  But there's not much you can do other than send it all back and there is no guaranntee that any replacement will be better. Have similar problems sourcing materials

 

Had similar problem with Gaboon I was using for the cockpit coaming.The original satinwood ply did not have this problem so was caught out when using a bull nosed plane to clean up epoxy, went through the top ply without realising it as second ply was same colour.

 

If starting again I would coat all ply with resin before i did anything else - remember to wash off the wax though when dry.

Understand that this can make bending to shape harder but the protection you gain to the surfaces seems worth it, even if it is only to stop staining by thickened resin drips - which are many, believe me.

 

Interested  to see opinion of others.

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Chinese ply will have thin outer skins. If you're finishing bright you'll have to very, very picky when doing scarfs. A little bit off and you'll grind through the outer ply when fairing the not-so-perfect scarf. Other than that the Chinese ply works, but a brand name, Joubert is the one I can source in my area, is real nice stuff. Except for that dang sticker . . .

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Photos?

Yes photos would have been smart. Unfortunately the ply is about 20 minutes away in my friends garage. Maybe I can get him to take some pics.I am not sure of the brand but along with the dot matrix style printing of "BS1088" there is printed what appears to say "Martinply". I am told it comes from a mill in Guernica (sp) Spain. I am reluctant to name the distributor but it is one that historically has a good reputation on this forum from searching through old posts.Other than the three thinner plys, the sheets look great on both sides and show no signs of voids. The 3/8 is 7 ply and has the same issue where every other ply is thinner though not as dramatic.
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Given that quality name brand BS1088 Ply costs roughly 15% of the total material and consumable cost of most sail boats I have a very hard time understanding the desire to economize with Chinese BS1088 marine ply.

 

I simply have no confidence in Chinese ply.  It may look the same and it might work well.  but face it.  If the Chinese manufacturere took  shortcuts you can not see, and it proves substantial later on,  How Catastophic will it be?  How hard will it be to correct?  What will it cost to upgrade the ply later on?  Will it be worth saving even half on the ply?

 

I would never ever consider ever using Chinese ply on any boat I build.

 

The downside is to great.

 

I would shave somewhere else.  Something that can be upgraded easier later on...  I would opt for less riggin early on that I can easier upgrade later.

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If Okoume was too dear, I might consider Merranti Hydroteck at about half the price.  While 20% heavier it has added benefit of increased rot resistance over Okoume.

 

But again, upgrading to lighter Okoume at a later point once the boat was built would be difficult....

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I used Meranti Hydrotek for the bottom of our CS20.... very fine stuff, but WOW can it give one hell of a sliver! And if you don't cut with a very sharp blade, you might also get some splintering bad enough to require a little filler. But it's strength and quality are beyond doubt. I've always been glad our hull bottom is made from the denser Meranti wood, but by comparison, building the rest of the hull from Okoume was a treat. The Okoume BS1088 (we ordered ours from Boulter Plywood in Massachusetts) was so light, beautiful, easily workable... really a joy to use.

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I think BS1088 allows for thinner face veneers. There should be no voids - You can't really verify that for sure without making some cuts, but you can inspect all the edges of all the sheets and if you see no voids that may be a good sign. I can't remember whether patches in the veneers are allowed. If you surf the web a little you can find a description of the BS1088 standard - It lists the acceptable veneer thicknesses, etc.

I'm not familiar with Martin Ply so I can't comment on the marking.

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I had a couple 6 mm sheets like that. Made in China. The stresses are not well balanced in a sheet that has most of its grain running in one direction. Joubert has 3 plies of 1 mm and two 1.5 mm and their sheets stay nice and flat. To re-use cut offs from the chinese ply was difficult because everything curled up like lettuce after a few weeks. There were some voids too. Not trying to scare you but re-read Ray's comments - I think they are spot on. Keep it dry, keep it flat, don't sand it too too much, coat it right away and support it structurally if you feel you need to. PeterP

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I am told this is not Chinese. The 9mm seems ok. The 6mm on the other hand is pretty bad. Voids seen from ends, splits in face veneers, and paper thin (less than .5 mm) outer veneers in some places. I have $10 luan in my garage that looks a lot better.

Good news is supplier has agreed to take it back and issue full refund. I am glad because either way I couldn't spend countless hours trying to make a solid boat with questionable base materials.

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I think MattP has done about all he can. Smelled a rat, contacted the seller and sent it back. If your supplier was a back alley operation selling the "good stuff" for a fraction of what anybody else was, you got what you paid for. But if you were sold quality, paid for quality and got junk, you send it back.

 

I too live in a location that is not minutes, or hours, but days travel distance away from any of the known reputable suppliers of marine plywood. Guys like us are stuck with using mail order. About all you can do is trust the supplier that what he sends you is the good stuff as you won't get a chance to inspect it until it arrives. That the product has a BS 1088 stamp on it is meaningless. BS 1088 is a recognized standard, but so is a speed limit of 70 MPH. If nobody is going to enforce it, the standard will be ignored and is meaningless. Doing as Ray suggests and insisting on one of those recognized brand names will help as an assurance of quality. Going forward, I'm not sure what to expect with regards to quality. Someday it may all be junk and we have to find something else to use.

 

Until then, about all we can do is patronize reputable sellers who offer the recognized brand names, and hope for the best. If they send you junk, call em on it and name names and let them know you are naming names......and send it back. It's not a case of the reputable guys "should" no better. They DO know better. If they want to keep their reputation, they need to step up and do what they know is right.

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