Luan Plywood

[fooman2008]

Went into the lumber yard today and was wandering around looking at what some of the materials were going to cost me (1/4 ply is $22 a sheet! with one good side). As I turned to leave the stockman said come check this out and showed me a bunk of Luan Plywood (two good sides and $11 a sheet!). But I am unfamiliar with Luan and don't even know what it is. Now remember that the beast (boat) in question is a 1/35th WWII BB (battleship) that will be over 17 feet long. Will luan work for structural members (the keel will be three layers glued and screwed)? If I cut it in strips will it be flexible enough to use for planking. My plan is to fiberglass the entire hull so it might not be that big of a deal. But any advise, observation, answers about using (or not using) Luan would be appreciated.
Foo

[nick_75au]

If you fibreglass inside and out, even balsa will make a very strong boat, so I think the Luan ply will be fine, only problem will be whether the glue is waterproof in the ply. How much is cedar or some other form of light weight timber to build along the lines of this page. use the ply to make temporary bulkheads that you lay the strips over. Fibreglass outside, then remove from formers and glass inside. then put any bulkheads etc that may be required

http://www.laughingloon.com/shop.tips.html

Do some research on canoe building, the hull you want to build is not far off the shape of a canoe ;)
Nick

[AndyKunz]

Luan is a kind of mahogany.

Wide open grain, poor quality adhesive between the laminations.

Usually reserved for cheap door skins.

Google has a lot more info - those are just my experiences.

Andy

[steamboatmodel]

Here is a site with some answers
http://www.windsor-plywood.com/FAQ/Plywood+QA.htm
Plywood - QUESTIONS & ANSWERS

What is the difference between Luan Plywood and regular good-one-side plywood?

Good one side is a recognized grade for Canadian made Fir plywood. This panel is obviously made from Fir veneer and bonded on exterior grade resins. The face is well sanded, repairs and natural defects (knots, splits, etc) are limited. For further info try the Canadian Plywood Association, www.canply.org.

Laun is a term to reference a group of wood species. Laun plywood's come in a variety of grades, some of which are similar to Good one side. Launs are usually bonded with interior grad resins and are not equal to Fir plywood in structural strength.
Regards,
Gerald.

[Umi_Ryuzuki]

Might be a bit tender for frames, but
I have been known to use foamcore for cheap frames.
(greenseaships uses cardboard) ;)

I used some as a deck for my Capitani Romani class cruiser.
It cuts nicely with just a utility knife, but I had a heck of
a time sealing the grain. It was very course.
Ship built up well though. :)

[norgale]

Fooman that Luan is what is used for top and bottom covers on bunks of plywood especially if it comes in from overseas. The grain of the wood is very course and will suck up a ton of epoxy and the laminating glue isn't very good at all. I don't think this would be a good material for any model building especially boats. Pete

[craig_c]

Forget it!!

And ya can bet at that price, the glues are NOT waterproof!

[steamboatmodel]

I did a check after posting the above information, The model Boats our Scout Troop made from the Luan plywood have all delineated over the past 5 years except for one which was fiber glassed inside and out. From this results I would not recommend its use. It would be better to use baltic birch plywood if you can get it in the sizes you need.
Regards,
Gerald

[BigDutch]

Go down to your local plastics supplier, we use Laird Plastics, and ask to see some gatorboard or pvc board.

[fooman2008]

Hmm Gatorboard? That is that corrugated plastic board that they make stiff, generally disposable signs from? Same stuff they mention in the JAP airplane section in the aircraft board?
Dutch, the craft I want to build is a 1/35th scale WWII BB (Idaho BB-42) at that scale she will be over 17 feet long and displace over 1500 pounds (I want to make it sit down scale), If that is gator board you are talking about I'm just not sure if it could take the strain.
Foo

[Umi_Ryuzuki]

The stuff you are thinking of is corragated plastic.
Gatorboard is the same as paper foamcore board, but
the coating is a plastic instead of paper.
PVC board is also know as Sintra, and is a bit stronger
than gatoroard, as it is plastic through and through.

If this is for your manned model, I wouldn't use any
of these materials as hull framing. Maybe as decking or
superstructure, but not to build up the hull.

[Kmot]

Since your own butt is going to be in this boat, you probably just have to bite the bullet and spend the money so you don't sink! ;)

[arrow5]

Agreed Kmot. Dont skimp on quality , the Coasties dont like it ! It is SPAD aircraft that use "Corroplast" as used for real estate signs, not many Japanese models use that form of construction. Foo did you get the plans yet ?

[OhioMike]

Would you build a canoe or row boat from this stuff?? Enough said!

[fooman2008]

Got to wait to get the money on the credit card for the plans (probably Thursday). Further question would Luan, in strips, work for planking? Since the entire thing will be glassed inside and out I would think that the skin would be as much for form as anything else.
Gatorboard or sintra sound like the ticket for the superstructure, and possibly gun turrets (turrets are armored to withstand at least the caliber of gun they hold) and mountings for lightness and ease of cutting.

[nick_75au]

Going on what the others have said I will go back on what I said in my first post about it being OK :o , but I was worried about its internal strength. Use it for temp bulkheads etc bit not for the main hull, did you check out the canoe building sites? I would think most solid timbers will work, there's too much chance of the internal layers separating within the ply and then you loose all laminate strength. If you planked it with ply, I would then consider using it as a male plug, cover it with packing tape and just make it a solid fibreglass hull and dicard the plug. The money you save on the timber then will have to go in making a sufficiently thick solid glass laminate.
Food for thought
Regards
Nick

[Predreadnut]

If its going to be that big and heavy, you need to make the frames out wood at least 1in thick. Guys are scratchbuilding 1/96th scale warships with 1/4 to 1/2 in. frames,and your model is going to be nearly three times that size.(and weight) You could cut your frames out of 1" x 12"'s or you could glue up two,1/2 in thick 4'x8's and cut them from that. For stringers, use 1" x 1"'s or 1"x 2"'s . With fiberglass on both sides the luan might be just the thing for sheeting. Im assuming your looking at the 1/8" thick stuff? It should give you enough flex to make the curves. If you go with the luan, I'd space my frames fairly close together. If your sailing around in a 1500lb model and hit the dock, thats alot of force, and you dont want to punch a hole in you ship.

[OhioMike]

Luan ply has voids in the bonding space. Its strickly an interior finishing ply. Basically a real weak laminate. Ever been kayaking? Youll be trapped in your personal ship far more than kayakers are just with an apron. Remember that when your crusing around in your ship!