Wood for Spars

[Don Silsbe]

Finding good material to make spars for our boats has always been difficult.  I love Sitka Spruce, nut the cost and availability are prohibitive for me.  Lumberyard spruce works.  But it is getting harder to find.  I read something on the Duckworks Facebook page that I thought was interesting enough to share.  Several builders there have used poplar for their spars.  They say that you can bleach out the green by exposing it to sunlight for a few days.  What are your thoughts about using poplar?

[Pete McCrary]

I’ve had success with Southern White Pine.  It has a good strength to weight ratio, but fairly expensive for clear pieces.  A few knots are tolerable, which can be drilled out with a hole cutter saw and then plugged.  Also Douglas Fir — available at Home Depot in large widths (2 x 10s or larger in long lengths).

[PadrePoint]

For what it’s worth... I used a 10 foot 5/4 x6” deck board from Lowe’s to make the boom for The Wheezer’s Spindrift 10.  I cut it to length, ripped it in half, and epoxy glued them together for a full two inch thickness.  The boards here (at Lowe’s) are southern yellow pine.  It was easy to select a completely clear board with no bend or twist from the pile and many great boards had interesting grain patterns. It was pressure treated and I let it dry some before working with it.  I glued opposite end-grain together. 
 

Since the outside surfaces were planed and sanded, bringing it down to plan dimensions, the green treatment disappeared leaving the nice yellow appearance.  (Southern yellow pine is what has been in the kits I picked up from B&B.)

 

In the photo, the top and bottom two pieces are SYP from B&B for my ski-boat build. The top two were epoxied. The middle piece is the boom I made from a Lowe’s deck board. 

[Hirilonde]

Sitka Spruce is my #1 choices.  But price and availability are why I didn t use it as well

 

Alaskan Yellow Cedar is great, if you can get it.  When I was in RI it was available 10 minutes down the road.  I made my oars for my Lapwing out of it.  Here in FL no one has even heard of it.

 

Douglas Fir is a tad heavier than ideal, but it is what I used.  I made my Spindrift boom, both Lapwing masts and sprits. You can likely get some nice pieces if you are willing to create a little scrap getting the best parts even at a big box store. (cringes at the thought of big box stores) By the board wide if you have to and figure out how to get the best part of it.

 

I am skeptical that you can bleach Poplar and lose the green.  I would try it first.  I like Poplar, but it is ugly. The heartwood is white, but hard to find.

[Don Silsbe]

I’m not making new spars at the moment.  I was mainly sharing this info off of the Duckworks page.  Because of some of the stuff I see on that page, I was initially skeptical,  but they said that Dave Gentry and Dudley Dix recommend it.  One guy used it for his yard and boom, and was pleased with its performance.  It is good to have options, when Sitka Spruce is so hard to come by.  Next time, I’ll dig a little harder for Doug Fir.  But it’s good to know that Poplar might work.  We have loads of that around here.

[Randy Jones]

I'm in market for a new boom for my CS17.  What's the current thought on laminated verses solid spars?  I'm thinking of three options:

Option 1 a $2.05/lf lumber yard 2 x 4 SPF stud (Canadian spruce) cut down to a 1.5 inch square boom.

Option 2 is that same stud ripped into three strips and laminated together with the the middle piece flipped end for end so the grain does not align. 

Option 3 a single piece of clear spruce easily found here in Washington State but not inexpensive. 

[Hirilonde]

I bet all would work.  You may need to do a little culling of the pile to find the right board, and may have to buy a bigger piece than you need so you can cut out the good part. Can you get Douglas Fir?  I know first hand that it works well.

 

On a side note, the lumber marking of SPF has always made me laugh.  I never heard of a Spruce Pine Fir tree. It actually means that you don't know which you got as all were considered acceptable for the structural rating it was given.

[Paul356]

I'll second the vote for Doug Fir.  Otherwise, look for a wider piece of "SPF" that has a 1.5" swath of straight grain through it that you can rip out, and you should be set.  If the ripped piece curls on you, then your idea of 3 pieces would be good, or slice the ripped piece in two, swap ends, clamp straight when gluing.   I guess the possible need to resaw the slided piece means you should cut it oversize the first time, doesn't it.

[Randy Jones]

Doug fir is readily available here and seems to be a lot stronger than spruce.  I'll try a stick of fir.  If the weight is reasonable they'll be no reason to screw around laminating anything. 

thanks

[PeterP]

I have sitka spruce sitting in the garage. Six pieces left over from the last boat I built. 2x6x16ft. Five bucks a board ft. You pick up in Greenville,NC. I'm cleaning up.PeterP

[Mark Rendelman]

When I built my spars I laminated Doug fir and mahogany then cut them into a hexagon I think I will taper the ends to a round shape?

[Hirilonde]

Mark, check the plans.  The Lapwing called for a 1 1/2"x1 1/2" tapered to round at both ends. Not sure that the octagon will mean much less meat in the middle, but that is where it is needed most.

 

[Mark Rendelman]

Dave

My spars are 11/2x11/2 across the flats I think they will be all right 

[Don Silsbe]

On 6/6/2021 at 8:07 AM, PeterP said:

I have sitka spruce sitting in the garage. Six pieces left over from the last boat I built. 2x6x16ft. Five bucks a board ft. You pick up in Greenville,NC. I'm cleaning up.PeterP

You have six of them?  I’d like to buy one or two.  When can I get it?

 

@Randy Jones— “Washington state clear spruce” sounds like Sitka Spruce to me.  It is has a very high strength to weight ratio, which is why I love it.  A well-culled single piece of SPF is all you really need on a CS17 sprit.  But one made of Sitka Spruce will be lighter and more golden in color.

[Randy Jones]

I'll pass on driving to NC for wood - hope it finds a good home on a boat. 

The Spruce available in Seattle as SPF studs is certainly golden in color and probably Sitka Spruce.  It made a great chicken coop but I haven't spotted a piece yet that is clear enough for a boom.    I have no doubt that a piece of clear spruce with tight grain would be ideal but it doesn't look like I'll find it in the SPF stud pile.     

[Mark Rendelman]

Try to use vertical grain Doug fir

[Don Silsbe]

@Mark Rendelman— Here in the Appalachian foothills of North Carolina,  we have more Darryls than Dougs.  “Tulip Poplar”, which is actually a Tuliptree, is very prolific. It is cheap and straight-grained.  I might play with it, unless I can snag a couple of those Sitka 2x6’s.

[PeterP]

Don, I sent you a PM. Peter