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kbowen
12-13-2011, 11:38 PM
Has anyone used Laminated Veneer Lumber or Glue-Lam, etc, for keel stock in a boat that gets sealed in Epoxy / Fiberglass?

jim shula
12-14-2011, 12:06 AM
LVL lumber is used quite a bit by Tolman Skiff builders for stringers and framing on the transom where the motor bolts on. Some of it comes with a waxy surface which you have to scrape off before laminating cloth to it.

AndreasJordahlRhude
12-14-2011, 07:58 AM
Stear clear of LVL (laminated veneer lumber) for anything boat related. It is full of sapwood and voids. Even if it is made from Douglas fir/larch, it will be full of sapwood.

Structural glued laminated timber can and is used in marine construction. However, it must be specifically manufactured for the application. You cannot just go out and buy a stick from some wholesaler and lumber yard and expect to use it in a boat. Again, even if it is made from a moderately decay resistant species such as Douglas fir/larch, it will be chock full of sapwood. Sapwood has No decay resistance.

Slathering it with epoxy and covering it up with fiberglass still does not solve the problem of it being full of decay prone sapwood.

All-heartwood of naturally decay resistant species can be utilized for the manufacture of structural glued laminated timber or pressure preservative treated lumber can be used. It can be custom made for a boat or other marine applications.

You can find manufacturers of structural glued laminated timber in USA by contacting the American Institute of Timber Construction (AITC).

Andreas

AndreasJordahlRhude
12-14-2011, 08:04 AM
Here is use of structural glued laminated timber in a ship. In this case, a 224 ft. long wooden MineCounterMeasure (MCM) ship built in the 1980s. All heartwood white oak frames and deck beams. All heartwood Douglas fir/larch keel and keelson. Manufactured in Peshtigo, WI.
http://i232.photobucket.com/albums/ee189/ThompsonBoat/Sentinel Structures/MCM-201.jpg

kbowen
12-14-2011, 09:36 AM
LVL lumber is used quite a bit by Tolman Skiff builders for stringers and framing on the transom where the motor bolts on. Some of it comes with a waxy surface which you have to scrape off before laminating cloth to it.

This and the more recent reply (basically, "Don't do it") seem to differ, so I guess I wonder how the Tolman skiffs have held up with this construction? How old is the technique?, has there been rot within the plies? I have dealt with old, first-generation FRP boats that used plywood for stiffening in the transom where some small nick in the plastic caused all the ply to turn to compost, and I don't want to repeat the experience. But if the interior is ventilated and easy to inspect for signs of leakage or stagnant water, is LVL worth considering?

AndreasJordahlRhude
12-14-2011, 10:34 AM
I know nothing about Tolman Skiff. But if they are using LVL "off the shelf" there is a huge danger of imminent decay in those members. No matter how much googe they slather on 'em, any penetration from a fastener or gouge will potentially introduce moisture into the wood. Unless they are using properly pressure preservative treated members. That's an entirely different story.

Laminated veneer lumber was "invented" in the late 1960s-early 1970s. It is meant for building construction. It has no decay resistance and is intended for fully under roof cover applications. TrusJoist (the inventor of LVL) quite a few years ago would null any warranty if it were used in a building with high humidity such as a swimming pool.

Andreas

JimConlin
12-14-2011, 11:19 AM
Balsa, another rot-prone material, has been used in boat construction with varying success.
I'd be asking whether a rot-prone material like LVL could be reliably encapsulated.

Sayla
12-16-2011, 12:03 AM
Here LVL has traditionally meant factory produced, stress rated, vertical laminations of peeled and spliced pine of whatever comes out of the tree - often slash pine so that's not as bad regarding rot and termites, but it is greasier; ie. it has some natural rot defense in way of it's oiliness, but hence more resistant to glues. These days they are treating the pine at the glue line for above ground termite resistance, so it's better, but I don't know about the rot - it's not pressure treated prior, but you may be able to find some. I think the glue is phenol resorcinol formaldehyde - it's said to be marine bonded.

Nothing wrong with the gluing process (likely much better than you can achieve yourself), but the timber selection is the issue. Glulam beams of selected timbers make more sense - hence laminated frames and keels. My thinking is 'why put all your eggs in one basket' - encapsulate a durable timber and all should be well - safety factor of two!

sayla

Bill Huson
12-16-2011, 08:16 AM
Balsa, another rot-prone material, has been used in boat construction with varying success.
I'd be asking whether a rot-prone material like LVL could be reliably encapsulated.

Varying success with balsa core was when manufacturers used it everywhere. More reliable now since balsa core is reserved for above waterline use, as in decks. Course there is still a small problem with folks punching holes in the core to mount things and failing to properly seal it.

AndreasJordahlRhude
12-16-2011, 08:21 AM
Laminated veneer lumber is veneers glued together with grain directions all the same way. Not like pywood with grain direction perpindicular in each ply. Resorcinol or phenol resorcinol adhesive is used (no formaldehyde in it). In North America primary species utilized are Douglas fir/larch and Southern Pine. It is full of sapwood and voids. It can only be manufactureed into straight billets, no curves possible.

No way would I ever use it in a boat and I highly discourage its use in a boat/ship.

Andreas

Feazer
12-20-2011, 06:36 PM
Here is use of structural glued laminated timber in a ship. In this case, a 224 ft. long wooden MineCounterMeasure (MCM) ship built in the 1980s. All heartwood white oak frames and deck beams. All heartwood Douglas fir/larch keel and keelson. Manufactured in Peshtigo, WI.
http://i232.photobucket.com/albums/ee189/ThompsonBoat/Sentinel Structures/MCM-201.jpg

You are only partially correct on your MCM structural data. However with regards to the use of LVL/Microlam products you are completely incorrect. The USN and in particular the example you brought up the MCM's used Microlam products extensively both as primary structural deck framing members such as girders and plankshears but also each and every deck level including the fantail is planked with Microlam T&G approx. 14" in width. There are no " heartwood white oak deck beams " in these ships they are as previously noted longitudinal Microlam girders forming the backbone for a gridwork of laminated fir half beams.

Regards

AndreasJordahlRhude
12-20-2011, 07:52 PM
The frames (ribs) of the pictured MCM are glued laminated white oak, not fir. They were not half frames, except for a few near the bow. They were full frames. The horizontal deck beams are also structural glued laminated timber white oak. I can see the cambered glued laminated timber deck beams in the photo. I know, I was involved in manufacturing those materials. I designed the jig for gluing the full frames. The trade named MicroLam used in the MCM's was a huge headache. Lawsuits were flying everywhere regarding them. And they were pressure preservative treated, not "off the shelf" items. The LVL MicroLam used in these 14 ships was for deck planking, not deck beams. LVL may also have been used for other components as you stated.

Andreas

Feazer
12-20-2011, 08:09 PM
The frames (ribs) of the pictured MCM are glued laminated white oak, not fir. They were not half frames, except for a few near the bow. They were full frames. The horizontal deck beams are also structural glued laminated timber white oak. I can see the cambered glued laminated timber deck beams in the photo. I know, I was involved in manufacturing those materials. I designed the jig for gluing the full frames. The trade named MicroLam used in the MCM's was a huge headache. Lawsuits were flying everywhere regarding them. And they were pressure preservative treated, not "off the shelf" items. The LVL MicroLam used in these 14 ships was for deck planking, not deck beams. LVL may also have been used for other components as you stated.

Andreas

Read my reply closer if you will please. I said nothing about the frames being fir as you note. As for half frames this is a term you just made up. Those shorter frames you refer to at the stem are known as cant frames. Again I never stated the Microlam beams were deck beams but girders — there is a significant difference in large ship construction. The half beams ( not full spanning transverse deck beams ) that land or connect to the girders were laminated fir. I realize you worked for the laminator but perhaps you were not involved in the construction process. Nevertheless you make an interesting point about Microlam products and we both agree entirely that they are a poor choice for most marine applications

Regards

Feazer
12-21-2011, 09:19 AM
Has this guy ever shown any sign of sense of proportion...let alone sense of humor? Hey bud, it's just names of boat parts...not really very important in the grand scheme of things.

Mr. Rhude has always been a helpful and well behaved sort; he does not deserve your rudeness.

And have a Merry Xmas.

My comments were not intended to be rude really it's just the way I write and deal with things everyday. It seems to me that you have inferred much much more than was written here. As for the use of correct terminology or as you say " names of boat parts " well the marine language and nautical terms are extremely important to me and should be to everyone here. These terms most of the time span centuries and international borders and allow all engaged in the marine world to communicate accurately and separately from other lexicons and professions. The maritime language is unlike anything else and is reserved in not only International Maritime Courts but banking, underwriting, construction and yachting circles of course. To delete or pass it off as just a bunch of part part names is to start down a slippery slope of ' left hand and right hand and front and back'

Back to the MCM comments. My intent was to clarify and point out that Mr. Rhude may have used a odd example to point out why Microlam products are a poor idea in a marine environment. These MCM's, being the largest of active wooden ships, utilize more of this product than any other vessel I know of to date. So the MCM's are an odd mix of lovely laminated white oak ring frames and other members that Mr. Rhude was involved in fabricating but also lots of Microlam planks and beams. In my mind he appeared to be cherry picking the facts on these ships while posting several other times that the stuff was completely inappropriate for boat construction ?

If by sorting out the facts and noting inconsistencies and/or errors I have crossed a line with you — so be it I really could care less about your accusations and remarks. I would prefer to see accurate information posted on forums like this and less he is a nice guy so let it go .

So with accuracy in mind let me say that Mr. Rhude is indeed partially correct re: deck beams of oak. I stand corrected partially. In reviewing some of the original construction drawings for these ships I note many areas where major beams supporting largers loads were spec'd out as oak. Majors such as those on the fantail where winch foundations were involved and in way of the windlass and other high load installations where a doubler or Major beam is necessary.

Regards

AndreasJordahlRhude
12-21-2011, 01:52 PM
Actually Feazer you are being quite rude.

In my posting of 12-14-2011 at 09:43 I said steer clear of "off the shelf" LVL in boats "Unless they are using properly pressure preservative treated members. That's an entirely different story."

Andreas