Glen-L.com

I am testing a pc. of 3/8 Baltic Birch ply by leaving it submerged in water. It has been in their for a week and can't seperate the ply. yet.
This is the strongest ply. I have ever come across, the 3/8 has 7 ply, and this stuff has 0 voids.

The stuff they try to sell here in KC. as marine ply is pitiful, a center core with thin vineer on each side.
The exterior ply they sell , not much stronger and has voids in it. The voids are a killer in 1/4'' plywood.

Any of you noticed how the quality of plywood has gone down in 20 yrs.?

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I was looking at some Birch ply just the other day. It was realy nice looking stuff, The only down side was they only had 1/2" ply on hand and I dont want to have to buy a full pallet of the stuff to get other thicknesses.

The quality of american ply is pitiful. BS1088 Meranti is nice stuff.
You can test the glue joint by boiling a little piece, if it is not good grade, it will fall apart in 20 minutes boiling.

Kens is right about USA's plywood. It's only fit for covering windows in the event of hurricanes. (not a likely happening here )

Baltic birch, by it's very name, has to come from the Baltic region. I have seen the box-stores labeling Finnish Birch as "Baltic"... Close enough, I guess. Test the glue, you never know what label the box-store stuck on what rack! The Finnish stuff is typically amino-plastic glue. Either will meet BS 1203 adhesive standard. If it has a grade stamp, look for SFS 2417 for all-birch composition or SFS 4091 for birch veneers with conifer cores.

Birch is prone to rot, but not significantly more than Meranti, epoxy should cure that problem. I have seen it used to rebuild transoms in vintage-tupperware restos, but never seen it rot if encapsulated. The stuff is a little heavy, but by far the toughest ply readily aval at "the box" store. If you plan to stain it for brightwork it needs some sort of sizing, or it wil blotch horribly. (voice of experience... it was an expencive lesson.)

I love the stuff, I have not been able to convince myself to build a boat with it. (nor how to hide another boat from the DA).

A note of caution.
I tested some nice looking ply , 3/4" 9 ply sold under the name sandeply.
The guy at home depot didnt know if it was EXT or not. I was using some for a cabinet job, so I cut a piece and boiled it in water for a half hour and left it sit in the garage soaking in water for 2 weeks. It still looked good.
Good thing I didnt use it though, I left a piece outside and after a month or so, it started to delaminate.
Needless to say , I DONT trust the boil test
Bob

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What would be the attraction to Baltic Birch versus anything else? I have heard of it before but not seen it used in a marine application. I think its mostly used for making cabinets and such.

True if encapsulated the rot issue doesn't matter but does it cost significantly less than a marine plywood?

Also, I would be concerned about weight. I am probably overly obsessed with wood weight but a wood boat can get real heavy if you don't pay attention to the weight.

Dennis

The "boil test" is not at all reliable... but I learned long ago, trying to explain it to someone is just an invitation to get flamed.
The proper test is explained in ISO 16983 through 16998 in the 2003 addition. (May be dif in more current volumes, that is the last edition I bought) Many panels will pass a 5 min boil, only to come apart like a $29.95 chinese kilt later.

It's a great test if you plan to go boating in a boiling lake though!

Someone call Al Gore... my lake is boiling? (I couldn't resist)

I tested sandeply too, it fell apart in the boiling can. I didnt have to wait a month, or hell, even 15 minutes, it fell apart if it rained outside.

Not trying to hijack this thread but what wood are you going to use for your framing in your race boat? Sitka spruce? I know that Eastern white cedar is the lightest wood in North America and it will not rot even when buried in the ground for years on end. Its only down fall is it isnt very strong when compaired to wood like Sitka spruce(low rot resistence), oak, etc.

It does have a history in boat building but its in canoes not motorized boats. I've been kicking its use around a fair bit. There are plenty of local suppliers around here that I can get good prices from. The stuff works really well, glues well, and holds fasterners pretty good too. Anyway just thought I would mention it.

Well I am trying something I haven't tried before. I will use a fair amount of yellow cypress on this boat (sometimes called Bald Cypress). It grows all over the south and thus is readily available. I also plan to use white oak on those certain parts of the structure where I have to have its strength, but cypress everywhere else I can. In the past I have used fir but around here it is not pletiful and it is sometimes hard to get quality stuff. According to the Glen-L website the weight of cypress is equivalent to fir, but in working with it I think it is lighter.

I would definitely look at the white cedar and consider how to use it in the construction of the boat. Glen-L lists it in its dicussion about boat building wood. It may too weak for certain parts of the structure like beams etc. but if you could use it in 50% or more of the boat you save a lot of weight.

Dennis

I used Cypress for my engine stringers, triple lamination. Glues great, works well, but it seems soft when I went to put in the engine beds. It chips/splits easy too.
However, it IS light, it DOES glue well, it does NOT swell up when wet.

Oh, and when I encapsulated the stringers, I noticed that Cypress will absorb epoxy seeminly forever. It didnt seem to matter how much resin I put on, it soaked it ALL up. I begin to think that if you dunked cypress into a vat of resin, it would soak it up until it was 100% through. It wont stop taking in resin until the resin kicks off.

whats the name of the stuff people use to thin epoxy so it soaks into wood better..something like cpec or something like that. Possibly doing that would allow the wood to suck in the epoxy faster..

My local wood source (Southern Lumber in San Jose, CA) sells Finnish (as in Finland, not finishing) Birch BS1088 MARINE ply. The stuff is just simply drop-dead beautiful. It is not inexpensive. I am using it for the new jet bracket on my Squirt, and I intend to use it for all 3/4" applications on the next boat I build.

It's my understanding that birch is less rot resistant than some woods, but as long as you encapsulate, I don't think this sould be an issue.

Just as an aside, Some years ago I did a lot of business in Finland. Birch grown there is a renewable resource - one of my clients was a paper mill in Pori, on the north-west coast of the country. They once told me that Finland grows 9 million board feet of timber more than they harvest, EVERY YEAR. Finland is a really nice place, believe it or not. The folks are friendly, everybody speaks english (even the kids taking orders at McDonalds!) and the countryside is beautiful. If you go, though, go in the summer - its damn cold in December!!

peace,

TRM

Hay the wood is still in the water and is strong as ever. It's been lets see 3weeks?

_________________
THE FRAUD WILL NOT GO AWAY..9-11 WAS AN INSIDE JOB...
http://www.youtube.com/watch?v=hZEvA8BCoBw

http://s147.photobucket.com/albums/r302 ... rd_photos/

Steve, how did the testing turn out?