Luan reliability?

Same here in Atlanta. They are gifted individuals working in lousy conditions (compared to a painter in front of a nude or countryside) in an under appreciated medium producing works of art. From my point of view… boat building is the same. I’ve seen some wooden boats that I would keep in my living room. Not because I’m afraid they might delaminate… but because it’s a work of art.

Hell’s right… I should just buy a frippen trailer and haul my own. I think the biggest things for me are picking out the wood and shipping damage. I guess I should assume that all marine grade would past my muster, so picking out might not be an issue, as I am paying for more qualified eyes to have culled them. Never bought something that big and fragile and have seen the shipping monkeys (sorry ahead of time to all monkeys out there on this forum) do their worst. Fragile on the outside of computer boxes seems to be red to a bull!

Well… I knew years ago mahogany was used for shipping crates and I guess I looked at it and “saw” (untrained eyes) mahogany! Well, you know what they say about assuming?! Thanks for the information. This was informative substantiation my engineering mind needed.

I know many who are gifted ironsmiths, goldsmiths, painters and sculptors. Some are dear friends. They buy the best (that someone else told them) and use it. Engineers are quite opposite… they are always asking why, how, when, where…

I’ve learned something very valuable here! I tried to place you into my way of thinking. You are an artist that also can do engineering. Your first wording is passion about your craft. Your masterpiece is the final product… a boat.

And you tried to fit me into your way of thinking. I am an engineer that also can do art. My work of art is the DESIGN! The boat is a minor inconvenience to show proof of concept! Even in my advanced material design work, cost is sometimes a factor. How often has Hollywood quoted the line about NASA’s buying practice… the lowest bidder! Fortunately, DOD, CIA, et al tend to be more… make it do the impossible… money is unlimited. A work of art in DESIGN is not always about using the best materials… it is about making any given material the right choice in how its used.

Who knows… maybe my proof of concept will come out and actually be a notable improvement and someone else might actually want one for themselves. I will not hold my breath… it is my first try. Although the main design concept is to make it faster, I’ll be using 20 foot Lauan hulls, fiberglass masts and Dacron sails all made by these very non-boatsmith hands. If its 10% faster, then think of what using marine grade plywood hulls, aerospace grade boron/aluminum masts and carbon/Kevlar reinforced Mylar sails will do for it! Maybe someone with deep pockets will ask me to design and a true boat artisan to oversee and construct a 150’ version. I can quit my day job and do something fun… Nah… that’s too much dreaming!

I will bow to your Majesty and I here offer a big wet one for you Brien!

 

In the trades, there is a strong inclination toward traditionalism, because it includes a vast body of knowledge assembled by the efforts of thousands of people who have come before. This pyramid of human knowledge must be respected. On the other hand it is a mistake to assume that it is infallible, otherwise no progress can ever be made. Designers challenge the past and the present to create the future. If the world were free of problems, we would not require designers. I am personally very grateful for their contribution.

 

First of all, Inquisitor, it was never my object to make "an issue" out of our little dispute. If I have emphasized my position a bit strongly, sorry for that.

My family ( from my mother's side) hosts merchants, builders, designers - the lot. Some of the foremost streets and buildings in Amsterdam are constructed and build by that part of the family in the late 19th and early 20th century.

Between the design and the actual building of - be it a house, an aircraft or ship, lies a long way of changes, additions, alterations and whatever is required to bring something that did not excist before into reality. I walk through the whole process, being the first witness when something comes from the drawing table and than going into production.

I am not only who draws the main design lines, but also follow the practical buildinmg process

Costs are always a major concern - specifically in my corner. In spacecraft many things are disposable and therefore do not require a long lifetime.

In boats it's different. Anything is related to lifetime and nothing is disposable - it is a difference in approach.

Boatbuilding is a mixture between design, engineering and construction, the one cannot do without the other. A design can prove to be succesful but if a n even succesful construction fails to come up, what is than the actual value of the design?
Without a good design, even if the construction is good, a boat will fail.

Therefore the reason that boatbuilding attracts many people but only a few manage to get through with it. It requires a lot of knowledge. Even if you are able to design a boat, that will not imply that you can build it. I go from the design room to the shopfloor and to all stations in between. So I have a pretty good knowledge of what can be used and what not.

It is a fact that I have been insulted for trying to build boats with eternal lifetimes. Of course there is a limit of what is required and what is practical.

So, lets shake virtual hands and forget our dispute, we are here within a band of brothers.

Brien

 

I've used lauan and CDX plywood to build small skiffs and kayaks. It is an inexpensive way to experiment. The cost of a 14' boat is about U$200.00. I don't mind using it for a week and then tossing it.

 

Here, here! I'll drink to that!

gonzo wrote: I've used lauan and CDX plywood to build small skiffs and kayaks. It is an inexpensive way to experiment. The cost of a 14' boat is about U$200.00. I don't mind using it for a week and then tossing it.

I think that's what Inquisitor is driving at, too. If you are in a learning process then a cheap, disposable full sized model makes sense. The materials should be related to the purpose, and mtbf (mean time before failure) calculations.

Of course Brien and other more conservative thinkers make a good point too, because your life or someone elses may depend upon the decisions you, as a designer, make. That's no small responsibility. A boat design is not just economic considerations. You may not be around when failure occurs. Substandard products that are temporary and experimental should not be allowed to drift into the world of consumer products. Label them or take a chain saw to them when you are done using them.

One other thought. Non-metal boats are based on the extraordinary strength of fibres embedded in a resin base. Luan is fibre and can potentially be very strong in an epoxy base. The problem is what you don't see beneath the surface layer. Often you find substantial areas of very punky, wood and plastic filler products with no long fibres. This material even when soaked in a resin binder tends to be very prone to hairline fractures since there is no long fiber to prevent it. Wood products for marine use are engineered and should be uniformly and dependably strong, without voids, knots and punky low fibre wood or filler. That is what you pay for - engineered uniformity that you can bet your (or your child's) life on.

 

I'm still curious as to weather we are talking about boats that are meant to be light little elegant racers or actual sailing boats? Even with all the negativity towards using lauan I am still going to use it in my project for two reasons. 1: anything covered in a sheet of 7ounce volan is tough!! ( I have made several surf boards which are foam covered in epoxy and tough as nails) 2: I'm sure there was a time when shipwrights scoffed at using plywood so why would using lauan be any different? So you cant tell me that by using lauan I will have built an inferior skiff, if simple Clarke foam or a closed cell foam can be made near bullet proof with the help of epoxy than why couldnt we assume that a wood no one cares for (aside from me) cant be made durable. Again I'm not building a yatch to Bristol standards I'm putting together a boat that will be sailed and dragged up beaches from the Erie to the Atlantic and if foam covered epoxy can stand up to the abuse a surfboard endures I see no issues with lauan, learn to glass!!!!

 

wow, what a blast from the past.

I too have built several surfboards with foam and epoxy/glass.

I can tell you there is no comparison in the strength of 6mm 5 ply marine grade plywood and 5.2mm luan with it two super thin face veneers and large (voided) filler ply.

not if its better in a particular application. The jump to a better material that is different is not what you propose. You propose using a far inferior material because its made in a somewhat similar way

you can certainly build a small displacement hull from luan and if you get the best pieces from a stack and use plenty of epoxy/glass on the joints it will hold up for a while. Or it may break right away along the void on the single inside ply. I have built canoes from luan they all eventually delaminated inside the wood.

Go for it, just dont put a lot of labor into the craft. Also be aware it could fail suddenly so do not be in a place where its failure would cause injury.

 

I have heard alot of mixed thoughts on the use of lauan but I'm sticking to my guns on this one if it can stand up to years under a vinyl floor I cant see it being that inferior but I thank you for your insights and opinions. As a carpenter I had seen all types of plywood split, delaminate and rot away. However I still think its all in the preparation. And if it should fall apart and turn to crap in the middle of the St. Lawrence Seaway lesson learned. Hopefully I can prove some folks wrong.

 

If your going to use it under vinyl in the galley of your boat, then your experience is applicable

Im sorry, but the stresses and lifetime fatigues put on the hull of a boat are hardly the same as an underlayment. Its just not apples to apples.

 

Ok ok I decided to go with BC pine although I'm sure someone will say naa but A: its affordable B: its available and C: well I dont have anyother reasons. Yeah I have a hard time sticking to my guns I think they call it a fear of commitment oh well so be it, till someone talks me out of it!!!

 

Hey JR-Shine its a little off the subject but what blanks did you use with Clake collapsing? Have you ever tried Bio-foam? I actually liked it better then Clarke which leads me to another alternative plywood has anyone tried bamboo plywood? ( the stringer in a bio foam is bamboo) I wonder how it would stand up...

 

I have used 3 EPS blanks from Marko, and a PU blank from Safari. Never tried the biofoam, but I would if I found a local source.

There are a lot of suppliers now of EPS blanks around here, mostly they are just planks with a rocker cutout. the Marko blanks come from a mold and have most of the work done. From now on i will just pay a local shape to give me a shaped EPS blank ready for glass; much better use of my time and I still get a custom board.

I finish my boards as I would a boat, epoxy primer and LPU topcoat; I liek the materials and it hides the overlaps

 

I have tried Marko but I didnt much care for the way it planes I never tried safari though but try foamez.com or homeblownus.com for the biofoam it has a nice almost creamish color and looks f-ing great with the 7oz volan and as far as the bc pine pluses minuses?

 

thanks for the tip, I will look more into the biofoam for the next board (if I shape it myself)

I do not know the properties of the BC pine. But the amount of voids in a plywood with only 3 veneers is crucial. A long open void on the inside ply reduces the strength sigificantly - it will oft snap in that place when you put a bend to the panel. Also, the thickness of the outside veneers should together be close to the same thickness as the inside veneer.

5 ply construction solves those issues, but only good quality marine plywood with have 5 veneers in something as thin as 6mm or 1/4"

 

Thanks man much obliged!