I'm sure there has been somebody who has built something with it but it isn't recommended. There are a llot of voids in luan and those will become weak spots in a boat. Yes, it's light and cheap but you better know how to swim if you use it. My opinion, others may differ!

George K

I beg to differ with George. You will not have to worry about swimming. The hull panels will snap before you ever finish twisting them into the correct shape.

Lauan may work (just)  for boats which don't have radical curves, but for the kinds of twists that make CLC boats so graceful and strong, you need something which is solid, flexible, light and strong. That'd be okoume or possibly meranti, but not underlayment.

Laszlo

I haven't used lauan extensively in boats, but others have had success (including whole kayaks).  From what I've read, it's not a good idea for the hull panels for the reasons that Laszlo and George describe.  However, if designed and glass-reinforced correctly, it can safely be used as a cost-effective substitute for deck-panels, bulkheads, skegs, etc. with no issues.  My personal view is that, even using okoume, the cost of the wood in a kayak pales in comparison to the expoxy, glass and other necessities, so skimping on the wood for primary parts doesn't seem worthwhile (particularly if your time is valuable).  However, for bulkheads and ancillary stuff, it's not a bad material to use. --Just my 2 cents...

 -Zach

Lauan comes in many different types and thicknesses and I’m not sure what you are asking about. The thick stuff (up to 7 ply) that is commonly used as sub flooring is too thick and stiff for the kinds of boats we are building here. The thin one commonly used under vinyl flooring may be thin and flexible enough but I haven’t tried it. There is another option called a door skin which I used on a pair of experimental kayaks (my design) about 8 years ago. They have the shape and all the bends of a Chesapeake. We have used them a lot (but not abused them) and they are still going strong.

Door skins are a little harder to use than the “O” stuff. The outer layers are thinner and it doesn’t cut as nicely. I epoxied both the inside and outside of the deck but didn’t glass it. (At one point the CLC standard was just to epoxy the deck not glass it.)They have been stored inside a garage and not left with water in them. If I wanted boats for long trips where they might not get dry for months I would probably go with the “O” stuff. If you were going to do like we do and day paddle them and keep them protected, door skins will probable work just fine.

The best part is door skins are very inexpensive. A sheet slightly smaller than 4x8 is less than $10. at Home Depot. There is no good supply of the “O” stuff around here and by the time it comes from CLC it is just under $100 per sheet. The choice is yours.

I hope this helps. 

Just be aware that there's doorskins and doorskins. It all used to be good stuff way back when, but now there's a lot of cheap junk from China in the big box stores with the good stuff far and few between. You have to be real careful when selecting the wood.

The kind with 3 plies, where the outer 2 are very thin and the inner one is just some kind of crumbly stuff should be avoided like the plague. It's worse than underlayment.

Another thing to watch for is the kind of glue. It needs to be waterproof. Since most doors are used indoors, many of the cheap doorskins use interior glues. Make sure that the ones you get are exterior grade.

The last big bugbear is voids. Since doors are flat, it's not as important for the center plies to be void-free as it is for boatbuilding wood. If you do go with doorskins, hold the sheets up against a strong light and look for bright spots. Avoid the sheets which have them.

So look for 3 even plies, solid wood interior ply, exterior glue and no interior voids.

As far as the economics goes, if you do get away with building your boat with doorskins, you will have saved nearly $200.00. But if the completed boat breaks, you're out the cost of the entire boat (wood, epoxy, glass, varnish, woodflour, hardware, paint, brushes, stirring sticks, sandpaper, wire, gloves, respirator cartridges, dustmasks, masking tape, shipping, etc.) plus your time and your family's patience and respect. And that's if no one gets hurt.

So you're gambling against something like 6 to 1 odds, about the same as in Russian Roulette. Feeling lucky? :-)

Good luck however you go.

Laszlo

How should you decide?

Well, as your original question was “has anyone used…..?”, ignore all the responses that don’t say they have either used it or tried to use it and see what you have left.

Another thought: If Laszlo is correct and it will break, snap or just can’t be bent into the correct shape, if you try it all you are risking is about $20 for a couple sheets of Doorskins. According to him, you will never get any further than trying to form the first few panels for the hull. Thus, You will never need to spend the money for the epoxy and fiberglass.

Woodie,

I like your logic.

Have fun,

Laszlo

Don't listen to Laszlo.   He's silly and keeps an inflatable sarcophagus in his office. (or used to)

 It can be done, but the 6mm lauan I used was not as flexible as the 3mm and 4mm (IIRC) marine ply called for in the plans.  I also glassed the interior side of each deck panel before fastening them in place.  (And then glass over the whole exterior.)   Since the lauan was butt-ugly, I had to paint it.  So, it can be done - but it's not optimal.  Build info here: http://www.blueheronkayaks.com (look for SK S&G)

Here is one of the boats I built with doorskins, note the natural finish.

Hi Ben,

   Here's the complete build of a hybrid using Home depot doorskin for the hull. It's fully glassed inside and out and hasn't had any problems in two seasons despite the hatch leaking and flooding the rear compartment every time it rains.

 http://www.facebook.com/profile.php?id=1171196421&v=photos#!/album.php?aid=23657&id=1171196421

         Chris

Ross,

You exaggerate. It's not a sarcophagus, it's a mummy. And as I recall, you had a plant.

And for everyone else, please remember that Benj's original question was for underlayment, not doorskins. Doorskins are a different beast than underlayment, if carefully selected. Having used underlayment in non-boat-related projects I can unequivocally say that it's not usable for something like a WD12, for example, and that it'd be pretty marginal for a Chessie, especially the front deck

Laszlo

I thank you all for your comments and will plan on buying  piece at home depot and playing with it prior to glassing.  I have a cousin that builds canoes and he informed me of a friend who used lauan with no problems.  I will keep you posted with my progress and more detailed information regarding the wood.

Just thought I'd toss a few cents in. I built a 17 out of luan (doorskins), and then comitted an additional sin... I used polyester resin from the local marine hardware store! I can hear everyone gasping! I completed the boat for under $300 out the door and it turned out great. That was four years and probably a thousand miles of saltwater paddling ago. She still looks pretty good -aside from a good bit of oyster rash and general expedition trauma. I've beat the crap out of this boat in big waves with a full load with no structural issues. It can be done.

Would I do it again?   ...Probably not

The wood is a pain to work with, lots of voids. I've had to repair rot several times around the hatch openings and along the keel when the glass was compromised. This wood quickly rots once it gets wet so you have to stay on top of it -of course its hard to catch when your hull is painted! Also I started off with a beautiful bright finished deck but its now painted because a ding on the deck allowed water in during a trip and I wound up with a big nasty discolored spot on the deck. Part of my problem is probably due to the polyester as its more brittle than epoxy and doesn't adhere as well. Though at $18/gal I'm not complaining.

Overall I have no regrets and have gotten more use out of the boat than anticipated but I plan to build a new one this winter and I'll be using okume/epoxy. The old boat will mainly be used with my sailrigMK2.

Just thought yall might find that interesting.

Lets have an ompa lompa fun day.

I am currently finishing up my wood duck12 using lauan plywood. I didn't have any problem with forming the bow and stern curves. It just took a lot of water and steam from an iron to get them into shape. However I did not take the same approach with the fore deck and cracked it near the cockpit. It can be done but I am starting to wish i spent the extra money for marine plywood. It is pretty ugly and I am painting most of the hull. 

A change since this post started is that CLC is now selling ply with pre cut puzzle joints. If/when buying ply for a project I find this a bog boost in value for their product. Saves some time for those of us that have an illogical fear of scarfs.

John 

lets have some fun and go wild.

Just to add some info. I did a test of applying epoxy to a piece of luan and okeme. the conditions were the same. I found the luan absorbed more of the epoxy . where the epoxy layed more on top of the okeme. If it means anything or has a effect on the finished product.

It means that the luan has a looser structure than the okoume. That translates into being more water abosrbent, more likely to get fatigue cracks, more splinters when cutting, more material removed when sanding and generally weaker mechanical strength.

Soaking the wood with epoxy does help with some of these issues. It plugs up the pores and keeps the water from getting in and does help bind the wood together, for example. But it can take a bunch more epoxy (at over $150 per gallon) and the result is still not as strong as BS1088 okoume, still splinters when it's cut and is still likely to get fatigue cracks. It will also be more expensive (time, electricity and sanding disks) to finish and less flexible.

You get what you pay for.

Laszlo

Laszlo, you make a valid point. I just wanted people to see the difference.