MDO yes or no?

[radman]

I have to scarf in some boards on a 18' sea skiff (plywood lapstrake) I was told by a
boat builder to use 3/8 MDO plywood since marine plywood is hard to come
by in the catskill mountians of N.Y. Any help would be appreciated
Thanks Curt

[bainbridgeisland]

I like MDO. It isn't marine fir plywood but is almost as good. I have had good luck using it for planking on open boats. It paints well and doesn't check. A few years ago I paid $34 per sheet for 1/2", so it is reasonably priced too. It does come in limited thicknesses though.

MDO has been around since the 1940's (that I know of) and has been used on boats almost as long. Today it is commonly used for signs, street signs, signs for shops and so forth. It has a long life when simply painted and left out in the weather.

Remember MDO is even heavier than fir plywood. Don't try to substitute MDO for okoume plywood unless you can tolerate the weight penalty

[Pelican]

Does MDO have a paper like facing on one side? :confused:

[Lowell Bernhardt]

Is MDO the same thing as malamine? I don't think it is but I'm not really sure where to get any of the stuff. Does either of the big box hardware stores have it?

Sorry, now as to your question, I've read only good about the stuff, if it were me I would say go for it. :D I'm thinking of using 5/8" for the bottom of my Diablo. Marine ply is hard to come by in Ohio too. And shipping the stuff is horriable. :eek:

Lowell

[B.Marks]

Lowell,
MDO & melamine have nothing in common, other than they are sheet goods. Melamine is particle board with a plastic face on both sides, not much use for it in boats. MDO on the other had has many uses as mentioned above. Check around with some local sign makers, they usually have it delivered to them, their supplier might even carry marine grade ply. You could also check with some local cabinet makers on sources or suppliers for marine grade ply.
Good luck

[On Vacation]

In MDO plywood, many times the backs have void. BUt that is easy enought o fix by filling it with thickened epoxy. Many of the sea skiffs were built out of it in the late 60s and early 70s. You can obtain a slick finish if you seal its face with epoxy two coats and then sand and prime and paint. Yes the weight is a little more, but plenty of sea skiffs are around with it.

[Chris Coose]

Oyster,
What plywood would you choose for a car top pram.
I've got to replace mine this winter. It has begun to leak like crazy through the ply probably because it is uppsdie down on the car most of the summer.
It has to be light so I can turtle it from the shore to the roof rack.
thanks,

[On Vacation]

I still like the 5 ply 1/4 ply and skin it with 4 0z. cloth. Opps, did I say glass? :D

[Chris Coose]

Where at home depot do I look for that? LOL

I guess I'll ask down to the yard and ask where they go locally for a product like that.

[ 09-08-2002, 10:30 AM: Message edited by: Chris Coose ]

[Pelican]

Oh NO! Oyster referred to GLASS! TAR AND FEATHERS, QUICK :D

[Mr. Know It All]

Lowell......Marine Plywood is not hard to get in Ohio. Try this place----> http://www.homesteadhardwoods.com/
Quality,selection and price are all good.
Be glad you live in Ohio :D
Peace---> Kevin in Ohio

[radman]

thanks for the info, a lumber yard near me is willing to order a sheet for
me. The orignal deck fore and aft were made of plywood with a vinyl
or painted canvas over it would the MDO be a good replacement or is that to
far from stock and hurt the value of the boat, not looking for a show boat
but would like to stay as close to orignal as possible.
thanks Curt.

[rkrough]

Radman
If you are north of Woodstock.Curtis Lumber in Ballston Spa stocks 1/2" MD0 and 3/8 is available. They will order marine ply for you also. They also have a yard in Delmar NY (exit 23 of the Thruway)which will save you another 35 miles of driving. You can get contact info at thier website. www.curtislumber.com (http://www.curtislumber.com)

Bellevue Builders supply in Rotterdam (where I-88 meets the thruway) may have mdo also. 518-355-7190
Bellevue usually has a high quality ACX in 3/8 and 1/2" that is IMO equal to marine plywood. I 'm using it on my boat
rich

[bainbridgeisland]

Originally posted by Pelican:
Does MDO have a paper like facing on one side? :confused: You can get MDO with stabilized surface on one side or both sides. I have always used the stuff stabilized on both sides.

I have found that most lumber stores can order MDO. This really doesn't cost more than your discount store (usually). This is because they do not have to finance and floor the material. It can be shipped with other orders so all they have to do is set it asside until you pick it up.

[John Bell]

My boat is built out of two-sided MDO. Only the bottom is is glass sheathed. I like it so far and would use it again. The biggest limitation for of MDO for the boats I'm likely to build is that the thinnest availible is 3/8" (~9mm). If there was a source for 6mm MDO, I'd be in hog heaven.

JB

[Dan Cavins]

Hey Radman, as always - I am not the expert - but here is my experience: First, all MDO is not created equal. I found stuff that was just crap, some that was ok, and other that was great. All called MDO. Don't ask me. My Hull is marine fir but much of the rest is MDO. I have found it, this is the "great" stuff, to be very void free. The 3/8 I use had five layers. In my glue tests I have never been able to seperate the paper side, the wood gives up first, though I always glue the wood side. I have also done the backyard test: throw it out there. The piece I tossed out over a year ago, unfinished, looks dang near exactly the same. No delamination. I feel fine about the stuff.
Now that said, I had people tell me not to use it and my boat is not in the water quite yet. But I'm confident with it. Besides I too live in Ohio and can go to the Contractor's Warehouse down the street and get the sheets for less than half of what I'd pay to get the marine ply. I have to think about the money thing. I'm also not afraid to try something different. Call me crazy. Whatever, that's my MDO tale. Good luck, Dan.

[radman]

Sounds like MDO is the way to go. I am picking it up tomorrow morning,
hoping to have the strakes replaced over the weekend. When it comes
time to replace the front and rear decks I think I will use the MDO there
also. thanks Curt.

[Dan-Q]

OK Guys, surely the stuff ... MDO ... is called something else out here in Quebec!!!
Anyone know the abriviation to MDO???
Thanks

[Bill Perkins]

Dan , MDO is an abrieviation for Medium Density Overlay , if that was your question .

[Dan-Q]

Thanks Atlanta,
Is MDO a multi-ply or a fiber board?

[bud]

It's plywood. I too have found a big difference
in quality in different lots, I got some recently that had wrinkles in the paper facing! No good at all. It should have a very smooth, slick hard face to it, otherwise it's useless. You don't want to sand it at all. If you apply finish to it you may sand the finish, but not the paper facing itself, beyond maybe roughing it up for paint.

[ 09-15-2002, 12:10 PM: Message edited by: bud ]

[Dan Cavins]

Just to add a couple of points here, Bud the paper surface should need no roughing up for paint. MDOs intended purpose, if I am not mistaken, is for sign making and the surface is designed to take the paint as is. Seems to do so the little I have done so far. Bianb. brought up the weight issue earlier. True. But I have found the paper surface so durable that I'm not glassing the cockpit and topsides as I would have with fir ply. This should easily make up for the weight. These are also more protected areas and easily accessed for repair. The deck gets sheathed. Outta' work I think. Dan C.

[Lowell Bernhardt]

Dan, you from Cincy? Where bouts? You say you can get MDO at the contractor's warehouse. What thicknesses do they stock?

[Dan Cavins]

Hey Lowell, tried to e-mail you but just in case I'll reiterate here. I live in Norwood to be exact. I get 3/8" MDO at the Contractor's Warehouse in Norwood. They had 1/2" too. now the bad news: they're closing shop this week. I'm going to get the name of the manufacturer of the stuff and hopefully we can find someone else localy who sells it. Let me know if I can help. Dan.

[BOBHERAS]

i get my mdo and hdo(heavy density overlay) at the local concrete supply house.this stuff is used for concrete forms. the hdo has a thin layer on one side like mdo but the other side has a much thicker layer.