Best wood for stringers.

[GaryMinor]

This is my first post. I have the second book, and plan to buy plans for either the 15' Mess About or the Cast Away. 

 

I've seen several suggestions for different wood used for stringers, but most of them are based on availability or cost.

The question is.... ignoring availability and cost, what are the better or poorer choices of wood for stringers? 

 

I have some poplar. How suitable is it? 

 

Gary Minor, in Raleigh, NC

[Kudzu]

The best wood is rot resistant, lightweight and bends easy.

Popular is not very rot resistant so it would never make my list.

[GaryMinor]

That helps. I would expect that straight grain and clear of knots should added to these desirable features. What woods are rot resistant, lightweight, bends easy, has straight grain, and is clear of knots?

 

Perhaps there isn't an ideal wood, but what are your suggestions? Remember, we are ignoring availability and cost.

[labrat]

I've used both Western Red Cedar and Paulownia and would recommend either. I've read good things about Northern White Cedar too.

 

There are not many timbers in the same weight range as these.

[Kudzu]

Most cedars, cypress and redwood. I have never used Paulownia but I want to try it. 

[LennieG]

I am new to all this but from what I have read and experienced in short time, Douglas Fir works well.

[mitchmellow]

Here's a link to a USDA Forest Service listing of woods and their decay resistance: http://www.fpl.fs.fed.us/documnts/fplrn/fplrn153.pdf

[Kudzu]

As you may be starting to see, there is not perfect or ideal wood.

 

I like WRC and cypress the best but wouldn't say no to several other woods either.

[Hirilonde]

Considering that these boats are stored dry and hence are only wet for hours at a time ( a day or so at the extreme ), I am not so sure rot resistance is even a serious concern.  Factor in also that most of us oil them at the least before skinning.  I use Alaskan Yellow Cedar.  It is a bit heavier than WRC.  But after comparing strength tables for both, and considering that Jeff specs his plans for WRC, I concluded I could scale down the thickness to 9/16" and still be at least as strong as WRC and only slightly heavier (less than a pound more for the whole boat).  I think the most important characteristic for stringers in a SOF kayak is a good straight grain to handle the loads from bending.

[DURRETTD]

I understand that many builders dislike using epoxy, but two coats of epoxy will eliminate the rot issue with poplar. It's readily available, cheap, and easy to work with - aside from the application of epoxy. Once I screw up my courage to mix the epoxy I also coat my plywood and laminate my cockpit coaming with epoxy.

 

Maybe Dave Finnegan has the best approach: the boats have plenty of time to dry, so just use what's available and oil the wood.

[Kudzu]

Epoxy, if not applied correctly can also make a boat rot MUCH faster. Someone was just complaining on another forum about a 3 year old boat that's bow was completely rotten. He had coated his plywood with epoxy.  While I don't know what happened it was either not allowed to dry out or I suspect the epoxy had a hole and water got in the wood. Then it has no way to escape and it allows the wood to rot faster. 

 

Many a wooden boat has been 'saved' by coating it with epoxy and in reality they shortened it's life. If done properly it's OK but done wrong it will quickly ruin the boat. 

 

Because of the cost and extra work I think  you better of to find a good wood and skip the epoxy.

[Hirilonde]

Many a wooden boat has been 'saved' by coating it with epoxy and in reality they shortened it's life. If done properly it's OK but done wrong it will quickly ruin the boat. 

 

Way too often epoxy is used to "save" a classic built plank on frame boat.  This effort is doomed before it starts.  These old boats do not act or react to their environment even remotely like the modern epoxy impregnated plywood and cold molded hulls. A boat must be maintained according to how it is built.  There is no short cut to preserving classic wooden boats except putting them indoors in a museum.

 

That being said an epoxy impregnated wooden boat can be built and maintained for many years. This implies that the methods and materials used are stable enough for this to work.   This forum has been host to such builds and builders long before Kudzu joined. I have built a couple myself and one I still own and sail.

 

I don't epoxy my kayak frames simply because it isn't necessary.  I have no doubt it could be done well, and easily.  I just don't see any reason to.