Mast replacement wood

Is cedar OK for mast wood? I can't find pine, spruce or fir in the dimensions needed.



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RE: Mast replacement wood

   Sorry, cedar doesn't have the required strength for a mast. If the problem is that the length of available timber isn't long enough, you can scarf shorter lengths together, as I just did on a mast that had to be 14'-3", and I couldn't find spruce longer than 9'.  I scarphed the staves and flipped them alternately, so that the scarfs were offset by about 3'. 

RE: Mast replacement wood

What's called cedar take in a wide range of species, some quite localized while others are more universal. I'd look at the dimensions required for that mast you have in mind first; there may be somthing in the cedar 'family' that would work for your needs but in most they tend to be fairly brittle when the soft ring portions have less strength compared to the harder portions in between. Tendency to splinter is a good indicator of this. 

RE: Mast replacement wood

   Thank you for the advice. I found 4"x4"x 8 feet douglass fir at Lowes for $15 each. I don't think it is the best quality (knots).

Should be OK?


RE: Mast replacement wood

What's the dimensions for the mast you want to build? Length, taper, base cross-section, any portion of length straight-walled before taper begins; rounded, square, eight-sided... lots of numbers for what's a complex shape in the end.

In my experience squared dimensional construction lumber (what that 4x4 is) are cut oftenmost from the very center of a sawlog. So with kiln-drying it's got a tendency to both split and twist.

These aren't meant to bear up under loads that'd make them bend so anomalies like those and the frequent knots aren't significant when it comes to compressive strength, which is what squared stock is typically used for: columns. And the calculations for this usage takes into account the effects those typical characteristics have on their ability to sustain the loads they'll eventually bear.

Masts though are more sophsticated. Those 4x4's may need some real TLC to yield enough material from which you can build your mast blank before finishing it to final size & shape. This all depends a lot on your skills, the time you have to invest, and what tools you have to use (or can borrow) to 'get out' the material you need from the stuff you've found.

RE: Mast replacement wood

   Thank you spclark. Where then, can I get the right wood?

This mast is to be 156" long and 2 1/2" by 2 1/2 at the widest. 


RE: Mast replacement wood

Jose so much depends on what this mast is to be used in (boat style) and your woodworking skills (to work with what you can find locally, rather than have to pay for shipping if you want something better suited to what you want to end up with) there's really no right wood exactly; one kind doesn't fit every need.

If you have the skills and tools available (either yours or what you can borrow) you ought to find what you can use at the local big-box stores like Lowes or HD or even a lumber yard.

Where are you planning to work on this project? If there's a Lowes there'll be other sources for decent lumber.

Douglas fir (not really a true fir but that's what it's called) ought to be available. Used in construction it's a standard product in widths wider than 6". For a mast blank to end up with a 2-1/2" square 13' long, bare minimum would be to start with a 14' "2x8" plank that you'd rip in half, giving you two 14' boards 1-1/2" thick by maybe 3" wide to glue together. It'd be heavy and the knots would make it less strong than if it were made of solid, knot-free material.

More sophisticated approach would be to buy enough lumber you'd resaw and surface to yield smaller sections that would be glued together. Scarfing shorter lengths into longer pieces both removes the inevitable knots but also gives you a stronger mast blank because you can choose the best wood from what you've bought.

But it's a lot of work.

An hour's drive from me there's a lumber yard in Madison Wisconsin that stocks aircraft grade Sitka spruce lumber. Probably the best choice for mast-makling it's expensive stuff now, not easy to find unless you're up in the Pacific Northwest.

Those 4x4's you found could be made to work if you're willing to turn much of them into sawdust & planer shavings "getting out" enough decent wood stock to glue up a proper blank.

But masts can be made from other kinds of wood too, with proper technique. Even pine if it's carefully chosen and costructed properly.

Some links:

RE: Mast replacement wood

   Wow , I didn't realize this would be so complicated for the mast. I definetely don't have these woodworking skills. I may be better off ordering a repalcement from CLC.

Many thanks for your thoughtful and detailed answer.

RE: Mast replacement wood


Which boat is it for? Depending on that it could be as simple Peter describes, or simpler. For smaller boats you can use pine boards from the DIY stores, just not the really knotty ones. Lowes and Home Depot have radiata pine from New Zealand that has no knots. Use 3/4" thick boards stacked 3 deep to get your 2 1/2". Lay the boards so that the outside boards have their grain running the same direction and the inside board opposite to that. That will help resist warping.

You don't even have to scarph the joints, simple butts will do. The other boards will act as massive butt blocks and reinforce the joint. Just be sure to stagger the joints so that they don't line up across the mast.

You can also make your shaping easier by cutting the boards to a rough profile of the mast before gluing them. That way you can remove the bulk of the material with a saw. Be sure to leave them oversized to allow for alignment errors.

You can also use a waterproof carpenter's glue like Titebond III instead of epoxy to glue the wood together, but you do want to encapsulate it with epoxy once the shaping is finished.

Finally, if you want to get fancy, you can cut the middle board into 2 pieces vertically and space it so that you have a hollow (or mostly hollow) lightweight mast, but you should probably leave that for your next mast project if this is your first ever.

Good luck,



RE: Mast replacement wood

"Wow , I didn't realize this would be so complicated for the mast." 


Doesn't have to be complicated Jose. Laszlo's approach will work just fine for your (I assume, from reading your other posts here) Peapod.

50-odd years ago I built a stripper scow from plans that called for a box-section mast 16' long. I used redwood & pine boards sourced from a lumber yard, glued up on a bench made from recycled packing crate lumber. Worked great, had gangs of fun with that boat until it rotted away. I put that up to youthful inexperience; the materials suggested were no match for the elements when it came to outdoor storage during the off-season.

That was my first boat. The second is CLC'S Waterlust canoe, just launched a couple of months ago. The 50 years in between have presented lots of opportunities for picking up all kinds of skills & experience that make this second boat a much more fulfilling endeavor. Life is for learning, after all....

I'm not an engineer by training; folks can take my diatribes too seriously & come away with that as a misperception.

However you approach building your first mast, you can trust that you'll learn much in the doing. So when you decide you want to do better on the second go-round you'll have the first mast's experiences to guide you in expanding your skillset.

RE: Mast replacement wood

Oh, and for a 2-1/2" square finished blank you'll need four 3/4" layers to start.

Use just three you'll end up with 2-1/4" max. with no allowance for finishing.  

RE: Mast replacement wood

I think you should be able to find #1 or #2 pine boards at you local Home Depot or Lowe's that should work just fine. As Laszlo says, you can stack 1" boards up to get the required thickness. Rip wider boards to width and cut out the knots. It's not much harder to use scarf joints than butt joints -- especially since you can use peanut butter epoxy putty to fill any cracks and make them as strong as you will need.   

RE: Mast replacement wood

   Thank you everyone for all the advice. Yes, this is for the Peapod mast. I did a poor job of tapering the one that came with my kit (in the upper half), and have ended up with a spar that is not perfecty straight and maybe 1/8" or so narrower than it should be on one of the side in the midsection. Not kowing how critical these imperfections are to the strength and function, I thought I should start over. I thought I could just take a 3 1/2" x 3 1/2" and cut away the excess, but now I realize it is not so simple. Maybe I should try to continue shaping the one I have, at the cost of some width?

RE: Mast replacement wood

I have a Northeaster Dory and accidently sliced out a fairly big hunk (maybe 1/4" inch thick quite near the boom attachment area). I just glued it back on using plenty of peanut butter epoxy and have had no problems at all for the past six seasons of sailing. 

Wood is incredibly forgiving stuff and you can do almost anything with thickened epoxy. If I were you, I'd glue on a 1/8" or 1/4" strip of wood just where the mast is too narrow. Sand everything smooth. Coat with epoxy. Varnish. And enjoy your one of a kind mast. It will be just fine.

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