Re: [bolger] Digest Number 2505 RE> luan ply
In a message dated 6/15/05 10:25:17 AM Central Daylight Time,
mkriley@...writes:
material, 1/4" nominal, some metric dimension actual, material designed for
overlaying the plywood, chipboard, OSB or whatever sub-floor of stick-built homes
to provide a smooth subtrate for vinyl sheet goods or tile. It is supposedly
made of waterproof glue and without voids. The quality may be pretty variable
and in my experience the void-less claim is doubtful. A more serious objection
to the use of this stuff where structural strength is a criteria is that the
thick core plys run perpendicular to the (very thin) face plys, which run the
long way on the panels. In other words, the mechanical properties of the stuff
is much different from that of conventional plywood.
The stuff is light in weight, readily available and doesn't (cross my
fingers) check. I've used it for a bunch of "boat furniture" and am not
dissatisfied with the results. I've seen a few amateur-built lapstrake boats built
with it and they seemed to be O.K. In those boats the overlapped strakes and
fiberglass reinforcement probably compensate for the fact that the strongest
axis of the material is 90 degrees off from the axis of the greatest loads on the
structure (assuming that one lays out the long axis parallel with the grain
of the external plys).
2) I don't believe that "luan" is "Phillipine Mahogany" or that "Phillipine
Mahogany" is "real" Mahogany. "Mahogany" was a wood found in in Central America
that was highly prized by boatbulders until it became unavailable or too
expensive. "Phillipine Mahogany" was a marketing name bestowed upon other species
of trees more readily available in the Phillipines when "Honduran" mahogany
had become. Like all other trees, "luan" and "balsa" must have a common ancestor
in their pasts, but I doubt if they are very closely related.
Always open to correction,
Ciao for Niao,
Bill in MN
P.S. - for those with a reasonable distance from Mpls/St. Paul, "Elmo's
Lumber" in Lake Elmo, MN has marine occume plywood in 1/8" to 7/8" thickness on
hand. I recently bought 1/4" stuff at approx. $60/sheet and 3/8" at approx.
$70/sheet.
[Non-text portions of this message have been removed]
mkriley@...writes:
> regarding the fascination with luan ply.1) The "luan" stuff that tempts local (MN) amateur builders is a 3-ply
> luan is a member of the balsawood family NOT Mahogany as in phillipine
> mahogany
material, 1/4" nominal, some metric dimension actual, material designed for
overlaying the plywood, chipboard, OSB or whatever sub-floor of stick-built homes
to provide a smooth subtrate for vinyl sheet goods or tile. It is supposedly
made of waterproof glue and without voids. The quality may be pretty variable
and in my experience the void-less claim is doubtful. A more serious objection
to the use of this stuff where structural strength is a criteria is that the
thick core plys run perpendicular to the (very thin) face plys, which run the
long way on the panels. In other words, the mechanical properties of the stuff
is much different from that of conventional plywood.
The stuff is light in weight, readily available and doesn't (cross my
fingers) check. I've used it for a bunch of "boat furniture" and am not
dissatisfied with the results. I've seen a few amateur-built lapstrake boats built
with it and they seemed to be O.K. In those boats the overlapped strakes and
fiberglass reinforcement probably compensate for the fact that the strongest
axis of the material is 90 degrees off from the axis of the greatest loads on the
structure (assuming that one lays out the long axis parallel with the grain
of the external plys).
2) I don't believe that "luan" is "Phillipine Mahogany" or that "Phillipine
Mahogany" is "real" Mahogany. "Mahogany" was a wood found in in Central America
that was highly prized by boatbulders until it became unavailable or too
expensive. "Phillipine Mahogany" was a marketing name bestowed upon other species
of trees more readily available in the Phillipines when "Honduran" mahogany
had become. Like all other trees, "luan" and "balsa" must have a common ancestor
in their pasts, but I doubt if they are very closely related.
Always open to correction,
Ciao for Niao,
Bill in MN
P.S. - for those with a reasonable distance from Mpls/St. Paul, "Elmo's
Lumber" in Lake Elmo, MN has marine occume plywood in 1/8" to 7/8" thickness on
hand. I recently bought 1/4" stuff at approx. $60/sheet and 3/8" at approx.
$70/sheet.
[Non-text portions of this message have been removed]
Signal (brand name) is available in 3/8's and 1/2" plywood--also in 4x8 and
4x10 sheets.
I am pursuaded that economics play a large part in the availability of
different plywood types. Ply wood boat builders must make up a very tiny
portion of the plywood market and not very many manufacturers will incur the
costs of building fine marine plywood or tying up inventory for such a small
market. On the other hand, the sign making industry--both private signs and
highway signs-- have needs which are similiar to boat builders and that
industry creates a large enough market so that manufacturers will build a
product to meet their needs.
If your boat is big enough to use 3/8's" ply, I suggest you seriously
consider MDO. I am in the last stages of building a Michalak "Toon 19" and
I've cut up a lot of MDO. It doesn't splinter or tear when cut with a saber
saw, a skill saw, a Dozuki saw, a low angle block plane, a power plane, a
chisel or a side grinder. I have only found one void and it was a pin knot
about 1/4 " in diameter. Signal MDO is really nice stuff to work with. You
should note that 3/8" is 50% heavier than 1/4" and the additional weight
sometimes require a second pair of hands to move around.
Having left scraps outside (including under a pile of shavings) during an
unusually wet winter, I am pursuades that the glue is waterproof, that
delamination will not be a problem, and that the overlay is permanent and
waterproof.
The overlay provides a ready surface for painting and it won't check. I
suspect that the overlay is not as resistant to abrasion as fiberglass, but
I haven't tested it and I don't intend to.
After 8 months of working with MDO, I think it is a wonderful product. Ask
me again in a year or two as I gain more time with it!
John T
4x10 sheets.
I am pursuaded that economics play a large part in the availability of
different plywood types. Ply wood boat builders must make up a very tiny
portion of the plywood market and not very many manufacturers will incur the
costs of building fine marine plywood or tying up inventory for such a small
market. On the other hand, the sign making industry--both private signs and
highway signs-- have needs which are similiar to boat builders and that
industry creates a large enough market so that manufacturers will build a
product to meet their needs.
If your boat is big enough to use 3/8's" ply, I suggest you seriously
consider MDO. I am in the last stages of building a Michalak "Toon 19" and
I've cut up a lot of MDO. It doesn't splinter or tear when cut with a saber
saw, a skill saw, a Dozuki saw, a low angle block plane, a power plane, a
chisel or a side grinder. I have only found one void and it was a pin knot
about 1/4 " in diameter. Signal MDO is really nice stuff to work with. You
should note that 3/8" is 50% heavier than 1/4" and the additional weight
sometimes require a second pair of hands to move around.
Having left scraps outside (including under a pile of shavings) during an
unusually wet winter, I am pursuades that the glue is waterproof, that
delamination will not be a problem, and that the overlay is permanent and
waterproof.
The overlay provides a ready surface for painting and it won't check. I
suspect that the overlay is not as resistant to abrasion as fiberglass, but
I haven't tested it and I don't intend to.
After 8 months of working with MDO, I think it is a wonderful product. Ask
me again in a year or two as I gain more time with it!
John T
----- Original Message -----
From: "pvanderwaart" <pvanderwaart@...>
To: <bolger@yahoogroups.com>
Sent: Wednesday, June 15, 2005 2:44 PM
Subject: [bolger] Re: Digest Number 2505 RE> luan ply
> > What is mdo?
>
> "Medium Density Overlay" is a plywood product used for outdoor signs,
> among other things. The general specs for the plywood layers are close
> to the specs for marine ply. In some cases they are the same, in some
> cases they are lesser. The "overlay" is a paintable, paper-like
> surface set in a resin that makes the surface ready for primer. There
> are different opinions about whether this surface is adequate
> substitute for a layer of glass cloth in epoxy, or if saturating it
> with epoxy, or just painting it, is adequate.
>
> MDO can come with all plies of the same species. In this case, it is
> nearly equal to marine ply. In other cases, the inner plies can be of
> lesser species. This makes the product only a little weaker, but may
> affect rot resistance. (Get a better opinion than mine on that!!)
>
> MDO has the great advantage of being available most everywhere in the
> US including a lot of places where marine ply is a special order item.
> On the other hand, it may only be available in 1/2 inch.
>
> Peter
>
>
>
>
>
> Bolger rules!!!
> - no cursing, flaming, trolling, spamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - Pls add your comments at the TOP, SIGN your posts, and snip away
> - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
(978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
>
> --
> Internal Virus Database is out-of-date.
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>
>
thats the one, thanks.
--- Inbolger@yahoogroups.com, Ron Butterfield <ronb_5@e...> wrote:
> Regarding the boat on the cover of BWAOM, here's the site of the
owner:
>http://www.boatdesign.com/tomboy/pages/cover.htm
>
>
> Regards,
> RonB
> What is mdo?"Medium Density Overlay" is a plywood product used for outdoor signs,
among other things. The general specs for the plywood layers are close
to the specs for marine ply. In some cases they are the same, in some
cases they are lesser. The "overlay" is a paintable, paper-like
surface set in a resin that makes the surface ready for primer. There
are different opinions about whether this surface is adequate
substitute for a layer of glass cloth in epoxy, or if saturating it
with epoxy, or just painting it, is adequate.
MDO can come with all plies of the same species. In this case, it is
nearly equal to marine ply. In other cases, the inner plies can be of
lesser species. This makes the product only a little weaker, but may
affect rot resistance. (Get a better opinion than mine on that!!)
MDO has the great advantage of being available most everywhere in the
US including a lot of places where marine ply is a special order item.
On the other hand, it may only be available in 1/2 inch.
Peter
Regarding the boat on the cover of BWAOM, here's the site of the owner:
http://www.boatdesign.com/tomboy/pages/cover.htm
Regards,
RonB
http://www.boatdesign.com/tomboy/pages/cover.htm
Regards,
RonB
What is mdo?
Martin Roberts
-----Original Message-----
From:bolger@yahoogroups.com[mailto:bolger@yahoogroups.com] On Behalf
Ofmkriley@...
Sent: 15 June 2005 16:18
To:bolger@yahoogroups.com
Subject: Re: [bolger] Digest Number 2505 RE> luan ply
regarding the fascination with luan ply.
luan is a member of the balsawood family NOT Mahogany as in phillipine
mahogany,Phillipine Mahogany is a name invented by wood importers.
. It is extremly rot prone and if the ply is made overseas the glues
most likely are substandard. When testing for water resistance the ply
should be under bending tension to simulate actual use. a lot of glues
let go under the heat and reglue when removed from the hot water. FWIW
mdo is the way to go and you can see the proof every day on the
highways. Luan ply is responsible for the horrible reputation of
oriental wooden boats and has caused many to biodegrade. I have made my
living from the 70's till the late 90's chopping out soupy luan ply from
boats in Florida.
rant over
mike
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--------------------------------------------------------------------~->
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts, and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930,
Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
Yahoo! Groups Links
Martin Roberts
-----Original Message-----
From:bolger@yahoogroups.com[mailto:bolger@yahoogroups.com] On Behalf
Ofmkriley@...
Sent: 15 June 2005 16:18
To:bolger@yahoogroups.com
Subject: Re: [bolger] Digest Number 2505 RE> luan ply
regarding the fascination with luan ply.
luan is a member of the balsawood family NOT Mahogany as in phillipine
mahogany,Phillipine Mahogany is a name invented by wood importers.
. It is extremly rot prone and if the ply is made overseas the glues
most likely are substandard. When testing for water resistance the ply
should be under bending tension to simulate actual use. a lot of glues
let go under the heat and reglue when removed from the hot water. FWIW
mdo is the way to go and you can see the proof every day on the
highways. Luan ply is responsible for the horrible reputation of
oriental wooden boats and has caused many to biodegrade. I have made my
living from the 70's till the late 90's chopping out soupy luan ply from
boats in Florida.
rant over
mike
------------------------ Yahoo! Groups Sponsor --------------------~-->
In low income neighborhoods, 84% do not own computers.
At Network for Good, help bridge the Digital Divide!
http://us.click.yahoo.com/B9pRWD/3MnJAA/Y3ZIAA/_0TolB/TM
--------------------------------------------------------------------~->
Bolger rules!!!
- no cursing, flaming, trolling, spamming, or flogging dead horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts, and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930,
Fax: (978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
Yahoo! Groups Links
regarding the fascination with luan ply.
luan is a member of the balsawood family NOT Mahogany as in phillipine mahogany,Phillipine Mahogany is a name invented by wood importers.
. It is extremly rot prone and if the ply is made overseas the glues most likely are substandard. When testing for water resistance the ply should be under bending tension to simulate actual use. a lot of glues let go under the heat and reglue when removed from the hot water. FWIW mdo is the way to go and you can see the proof every day on the highways. Luan ply is responsible for the horrible reputation of oriental wooden boats and has caused many to biodegrade. I have made my living from the 70's till the late 90's chopping out soupy luan ply from boats in Florida.
rant over
mike
luan is a member of the balsawood family NOT Mahogany as in phillipine mahogany,Phillipine Mahogany is a name invented by wood importers.
. It is extremly rot prone and if the ply is made overseas the glues most likely are substandard. When testing for water resistance the ply should be under bending tension to simulate actual use. a lot of glues let go under the heat and reglue when removed from the hot water. FWIW mdo is the way to go and you can see the proof every day on the highways. Luan ply is responsible for the horrible reputation of oriental wooden boats and has caused many to biodegrade. I have made my living from the 70's till the late 90's chopping out soupy luan ply from boats in Florida.
rant over
mike