Plywood horrors & testing?

[kbowen]

The most recent WB has a scary sidebar about catastrophic failure of supposedly marine grade plywood. I recently took delivery of $1100 worth of plywood and I am wondering how I can test it before putting it into my current opus. The stuff I got is from Homestead Hardwoods in Ohio and is described as BS1088 Hydrotek Meranti Marine Plywood. It has no Lloyd's stamp, and has a dragon logo which might imply an Asian supplier. The WB sidebar describes delamination when exposed to sun: Is there a recommended protocol for testing? Should I soak it in water and leave it out in the sun for a couple days? Help!

Ken

[artif]

I deal with materials on a daily basis.
Unless the material purchased comes with an endorsed (by a recognised certificating body Lloyds, TUV etc) certificate of conformity from the manufacturer, writing BS1088 on it means absolutely nothing e.g. I could write 24 carat gold on a piece of ply.
The current standard is BS1088-1:2003 and BS1088-2:2003, both parts are applicable. I would ask the supplier for a c of c.
This http://www.ttf.co.uk/article/timber-...ywood-317.aspx gives an indication of the problem. Lots of manufacturers claim BS1088 but have no independent verification i.e they can make it out of anything they want and claim what they want.
I have just come across some claims of meeting BS656 from a manufacturer, this standard has been withdrawn.

Testing by soaking in wa6ter, may test the glue bond, but won't really give an indication of the durability of the wood used in the veneers.

[Dusty Yevsky]

http://forum.woodenboat.com/showthre...esting-plywood

Here's a link describing a few different approaches to determine quality

[MN Dave]

Why not call Homestead and ask if they can provide a C of C? While they may not have lot control at the yard, they may have records that show that they buy certified material. At least they should tell you one way or the other. http://www.marine-plywood.us/bs1088.htm

Hydrotek has been discussed here before: http://forum.woodenboat.com/showthre...eranti-Plywood

[kbowen]

The "bottom line" of my OP was about testing: The WB article described ply that was dutifully encased in Googe, but it started delaminating in the sun anyway (painted). I might be less worried about interior bulkheads, but for the 1/2" stuff I plan to use on the deck, does anyone have a good protocol for testing? Do I need to Googe a full sheet and leave it in the sun, or is there a more efficient way? I wonder if the original ply in the article was too wet when it was encased, maybe vapor pressure pushed it up part?

ken

[Tom Lathrop]

Anyone who has worked with wood for along time knows that quality is a moving target and generally going downhill. Wood has not changed but the availability of the good stuff has become more difficult as premium material tends to go to the highest bidder for high end architectural uses here and abroad. American made douglas firof 60 years ago was readily available and most US built plywood boats used it. AB ply was beautiful quality stuff and Simpson Plywood Co. offered boat plans that many built from. As far as I know , no high quality marine fir plywood is available made in the USA now. For many years, a builder could trust imported marine occume, lauan or other (mahogany?) substitutes and not worry about it. All the while builders, especially novice ones, complained about the price of plywood and distributors started to import cheaper wood from far eastern mills that ranges for good to downright disastrous. As LLoyds stopped providing on site source inspection of the BS Standards, that stamp began to lose the trust we had relied on and many just slap it on junk and sell to those looking to save a few bucks.

For the current buyer, the boiling tests are the best guarantee that your plywood glue is adequate for boatbuilding. Other interior characteristics that John Harris discusses in the Woodenboat article, you will need to examine yourself. Still, a personal inspection of a sheet from other than known quality sources should be gone over, tapping and looking for delamination before using.

John uses and trusts Joubert (French) BS stamped plywood and I do also. There are other fine imported plywoods and they all demand prices to match the quality and there is no easy way around that fact. There is a steady flow of advice for those who will treat lower grade plywood with differing treatments and they often seem happy with the results. Properly treated fir plywood can make a high quality boat that looks a good as any. Experienced builders can work with lower priced plywood and come out fine because they know what problems too look for and how to get around them. Those shops building for customers don't tend to do that because it is not worth the time or risk.

[Canoez]

We've had some issues buying 12mm BS1088 Okoume plywood of late. Our vendor's supplier switched to Garnica brand plywood. About 1/2 of the sheets that we ordered had serious delamination issues that were found by the fact that we'd asked the supplier to cut the sheets down to 4'x4' nominal for our use. We then started tapping on the un-cut sheets when they came in - if delaminated they would "buzz" or not "ring". Note that this method will not detect interior voids.

We contacted the vendor's supplier about the issue and the agreed to start sending us Joubert brand product that we'd used in the past. We had similar issues with one sheet of the Joubert material, and have begun to question the supplier's storage and handling as being a possible cause. It may also be quality problems at the manufacturers, but to determine where the problem truly lies is very difficult for the end user unless it is obvious that no adhesive is on the internal laminations.

With a dependable vendor or supplier, they should stand behind the material if it is a certified product (BS1088,etc.) and replace any that you find don't meet certification when you cut the sheet.

As far as product which fails in use, I don't know what to tell you. The material will likely be replaced, but the work/additional materials that went into creating the craft is typically not covered.

With the high price of quality marine grade plywood, I have also begun to question whether there is a market of counterfeit materials out there.

[David G]

Having gone thru a sheet or two of marine ply in the last 35+ years in business, I can offer a couple of comments. First - I've had very few problems with the quality of materials. Second - the marketplace is always dynamic, now more than ever. That means that the possibility of defective products is higher than ever. Testing is not a bad idea. Third - the Hydrotek and Aquatek products are some of the least pricey, and therefore least likely to be counterfitted. Unlike the sapele mentioned in the sidebar - which is at the other end of the pricing spectrum. So I'd be surprised if you found it to be unfit.

[openboater]

http://forum.woodenboat.com/showthre...hear-me-SCREAM

[Canoez]

http://forum.woodenboat.com/showthre...hear-me-SCREAM

Kinda ticks ya off to be the manufacturer's QC department, doesn't it?

[Dave Hadfield]

Cut off a slice about 18" x 6", submerse it in water for a couple of days, and then leave it out in bright hot sunshine for a week.

If it warps a bit I wouldn't worry. If you can pull the layers apart, then I would not use it for the hull or decks.

The dishwasher test isn't bad either.

[SBrookman]

I had a delamination issue with BS1088 Hydrotek Meranti Marine Plywood that I used to build my melonseed. As fate would have it the first plank I made delaminated after it was installed. It was a slow release separation that didn't show itself until it was screwed, glued and beveled. ARrgghh..

The distributor replaced the sheet but now you have the fun of fixing it plus having an oops on the 1st plank of your new boat.

[Mo 'Poxy]

BS1088 Hydrotek Meranti Marine Plywood. It has no Lloyd's stamp, and has a dragon logo

Is this the dragon logo?









As someone else mentioned, the stamp may not mean much but I built the BW http://boatbw.blogspot.com using it and I was very impressed with the color and structural integrity.

[kbowen]

Is this the dragon logo?









As someone else mentioned, the stamp may not mean much but I built the BW http://boatbw.blogspot.com using it and I was very impressed with the color and structural integrity.

Yes, thats exactly the stuff I have. I got 25mm for the CB trunk, 18mm for some bulkheads, and 12mm for side decks.
ken

[drbooze]

Is Bruynzeel not available in the USA? In Bermuda it was the plywood of choice in boat building, for their unremitting commitment to quality? The stuff was expensive but I never heard of a problem...

[artif]

Just to follow up on the marking of plywood.
If it really does comply with the BS1088 :2003 standards and the manufacturer is approved by BSI it can have the BSI Kitemark.
Without the BSI Kitemark, which is very well protected, then the BS 1088 claim (stamp) is worthless.
However manufacturers may make their ply in accordance with the BS1088 : 2003 standard without gaining accreditation, but you are relying on their word as to the manufacturing process.
i don't know your sales laws in the US, but claiming something is of a standard without proof is often met with court proceedings (VW????).

[David G]

Just to follow up on the marking of plywood.
If it really does comply with the BS1088 :2003 standards and the manufacturer is approved by BSI it can have the BSI Kitemark.
Without the BSI Kitemark, which is very well protected, then the BS 1088 claim (stamp) is worthless.
However manufacturers may make their ply in accordance with the BS1088 : 2003 standard without gaining accreditation, but you are relying on their word as to the manufacturing process.
i don't know your sales laws in the US, but claiming something is of a standard without proof is often met with court proceedings (VW????).

Is BSI still certifying and enforcing the BS1088 standard? I thought they had stopped. I know they no longer maintain the BS6566 standard.

[artif]

Is BSI still certifying and enforcing the BS1088 standard? I thought they had stopped. I know they no longer maintain the BS6566 standard.

BS1088-1 & 2:2003 is the current standard, both parts are applicable, part 2 being applicable to the glue bonding.
http://shop.bsigroup.com/ProductDeta...00000030062733
http://shop.bsigroup.com/ProductDeta...00000030062735

Without a kite mark or accredited certificate of conformity, the BS1088 label means nothing, other than the manufacturer knowing the value of the label.

[SBrookman]

Going back to the OP's requests about testing, I'm not sure if that would really accomplish much. I had 6 sheets of that same Hydrotek and only had an issue with one sheet. It had a void in the middle of the sheet that didn't reveal itself until it was worked. But all the other sheets were fine, of course I inspected the heck out of them, as I should have done with the first. So testing one doesn't say much about the next one.

[kbowen]

If it really does comply with the BS1088 :2003 standards and the manufacturer is approved by BSI it can have the BSI Kitemark.
Without the BSI Kitemark, which is very well protected, then the BS 1088 claim (stamp) is worthless.s (VW????).

What is this "kite mark"
Op,
ken

[artif]

What is this "kite mark"
Op,
ken

This explains it https://www.bsigroup.com/en-GB/kitem...oduct-testing/
Apologies to the OP for the thread drift but this may help someone in the future.

[David G]

This explains it https://www.bsigroup.com/en-GB/kitem...oduct-testing/
Apologies to the OP for the thread drift but this may help someone in the future.

I certainly think it's a worthwhile digression.

It should be restated also, than a manufacturer CAN build product that meets/exceeds in every way the cited standards - BS1088, BS6566, APA's 'Marine' grade for softwood plywood (TT-043) - without being certified. And several reputable manufacturers do so. But the kitemark certainly does provide a level of surety that's not available without such a certification.