Mast wood choices

[Andrew]

SO I'm up to the part where I can start thinking about the wood for the mast...

I priced up Oregon (AU$22 per metre solid, AU$33 per metre flitch), I daren't price up cedar (and isn't it too soft anyhow??), so I'm thinking about maybe doing the 'birds mouth' thing. But it scares the b'jeebers out of me.

I have the woodworking skills of Homer Simpson [well maybe a little better, but not much!]. Will this cause me too much pain and heartache? Is it as easy to stuff up as Frank made it seem (sorry Frank ) ? Am I just wimping out?

I'm looking for some more inspiration here guys (and gals).

Andrew

[Arnie Eaton]

As it just so happens, I am in the middle of making my "birdsmouth" mast right now. I used a special router bit for mine but the table saw works very good also. Get the copy of "Wooden Boat" mag, Jul/Aug 1999, where a nice article about "Hollow Spars" is written. The article is well written and will lead you to making just what you want. I used staves 3/4" by 1 5/8" for my mast. It is slightly larger then 3 1/2" across. For wood, use Doug Fir if you can find it. Hemlock will work if you use the grade used in finish work for new homes. Either way be sure it is quarter sawn. I'm not sure what wood you have available "down under" but ask your local lumber people what would be best. You don't want cedar as it is somewhat brittle and you do want light weighting wood if you can find it. It should be light, bendable slightly and verticle grain for best results.. If you can't find the magazine, let me know (aeeaton@cybernet1.com) and I will copy it and slow mail it to you. Include your address in the e-mail.

[waynemunro]

I found a beam of north american oregon in a wreckers yard, NZ$ 100 (US$ 70 ish), 4.5m long, had enough for mast, boom, bowsprit gaff, etc. love the wood, love the grain, and it seems soo light (note I don't know a hell of a lot about wood).

seemed like a bargin to me. wonder if there are similar old beams removed from demo'd houses over there somewhere ?

[ken connors]

i used doug fir for my vacationer mast. i took quite a bit of picking thru the pile to find nice straight 16 ft 2x4s without a lot of knots. glad i only needed two. doug fir is very cheap around here, tho. only cost about 25 US$ for the two.

i was also hesitant about trying to make a birdsmouth mast, but i didnt want it to be too heavy either. instead, i attached the router blade to the table saw and routed out as much of the innards of each board as i could without weakening them too much. instead of glueing the two peices together, i sandwiched a peice of 1/2 inch ply between them. i think this will help stiffen it and help prevent warping or twisting; it has stayed straight so far. i left the ply 3/16 short on all sides and capped the endgrain with thin strips of meranti. the dark strip looks nice on the mast and prevents having all that exposed endgrain.

the routing also allows a hollow area to run wiring thru if want a light at the top of the mast. if you do rout it out , keep in mind where you will be shaping the top of the mast and where your hinges will be. you dont want those areas routed inside. good luck

[Andrew]

This is why I LOVE this board

Perfect answers every time!!

And I can feel a money/effort saving coming on...

If I combine Wayne's and Ken's ideas I should be able to get 2nd hand wood (cheap) and a lightweight mast without taxing my Homeresque brain.

Brilliant

PS. Ken, do you think you really need the ply between the fir? I would have thought that laminated fir would 'hold itself'

Thanx

Andrew

[Barry Pyeatt]

I'll toss my 2 cents worth in here too. I too would check the wood recyclers if you have any in your area. Often they have very suitable wood that they can't find a home for just because it isn't pretty. I've picked up many a 4X4 or larger that has been all beat up on the exterior, but other than being very hard, (from age), absolutely magnificent wood to work with. Cut off the damaged portions and you have great stock. Most often higher quality wood than you can purchase (freshly milled) today. Most often as well for rediculously low prices.

Ken used a length of 1/2" plywood most likely because he wanted to bring the laminations up to the full milled 4 X 4 dimension of 3 1/2" X 3 1/2". Our 2 X 4 stock after kiln drying and milling is 1 1/2" X 3 1/2 ".

Laminating up a couple lengths of smaller stock in the appropriate lengths is a good way to go and will probably save you a considerable amount of out of pocket costs. I would look for quarter sawn stock if possible and then lay up the grains so they lay ///\\\ If you need to lay up a length of plywood down the center, then you can do that in shorter sections. It will be plenty strong enough either way.

I would avoid Western Red Cedar, (Is this Oregon where you are at?) as it is too brittle and a bit soft for a mast, but it is used on a lot of smaller craft in some areas. Other types of cedar can be used, but as a general rule, they are all pretty soft and brittle once dried out.

For a good discussion on appropriate woods try the Glen-L.com site and read the portion on Boatbuilding woods.

Good stuff!

[Frank Hagan]

I imagine getting Douglas Fir "down under" would cost a fortune. What you need to do is find a suitable boat building wood that is grown locally. I remember a Wooden Boat article a long while ago that featured some names of woods local to you, and I had never heard of them. I did recognize one portion of a name, a eucalyptus, but not the specific species they mentioned.

If you can't find a boat builder, ask at the local lumberyard what they use for outdoor wooden stair treds. Here in the States, they use Douglas Fir in the west and Southern Yellow Pine in the southeast. That's also what they use for boat building in those regional areas ... not because they are the "best possible", but because they are the "best in the area" (the Europeans went nuts over Sitka Spruce way back when, but barring sending the Alaskan Fleet on a scavenger hunt, you won't find any of that around here ... or, I'll bet, in Australia or NZ.)

[Andrew]

Frank

I think Oregon (Australian) is comparable to your Douglas Fir. I've spoken to a number of people about this (builders, boaties etc.) and all seem to think it would be OK for the mast - just about all outdoor building around here (decks, pergolas etc.) are done with either treated pine or Oregon.

Andrew

[capt jake]

Oregon (at least here in the US) is short for Oregon Pine, which is really a nick name for Douglas Fir. Named so (as far as I can tell) because it grows predominately in the 'Oregon Territory'.

[Frank Hagan]

Common names for wood will drive you nuts ... so the thing to do is find out what the locals use and defer to them. I know here in the States that Jake is right, Oregon Pine is Douglas Fir, but that's no assurance it is there. But if the local guys use it ... then go for it.

[Joe Nelson CS#35]

Doug fir = Pseudosuga menzisii. Frank is right, common names suck. But I dont know where you will find the botanical name on lumber or anyone at a yard that knows their wood by anything but common names. Hemlock is commonly mis-identified or even sold as fir. Hemlock tends to have a more twisting grain and rarely holds straight when dry. Even douglas fir can be knotty and un-usable. Look for straight/vertical grain and low/no knots. It is hard to find even here in Oregon.

There is a guy in my area that has a portable saw mill. I might check with him and see if he may be a niche for good spar lumber.

[ken connors]

Andrew, to answer your question about the 1/2 in plywood, Barry pegged it. i needed something to make a square 3-1/2 inches. finding decent 4x4s is much more difficult and expensive and its very doubtful it will dry out without twisting.

[Andrew]

OK...

So I'll go the Ken and Wayne way, but (oh god no...not ANOTHER question!!) if the centre of the mast is watertight do I have to use 'good' plywood to make up the 3 1/2" square (as Ken did) or can I use a 'cheaper' grade.

I am asking not only to save cash but to save travel time. If I want anything better than CCX I have to go 400Kms to get it!!

Thanx again

Andrew

[ken connors]

if you cap off the endgrain as i recommended you can put pretty much whatever the heck you want in there

any plywood scraps laying around will do. ive even got some old fruitcakes my aunt sends me every Christmas that you could run thru the table saw and squeeze in there. but i think the plywood would be easier on your sawblade :roll:

[Barry Pyeatt]

Option 1 Pack a sandwich and go on a day when you can enjoy the drive.

Option 2 (and my personal preference.) Pick out an additional piece(s) of lumber only make this one either 1/2" X 4" or 3/4" X 4" stock. Pick out quarter sawn or vertical grain if you can get it. If not the best looking piece of plain sawn material that you can get from the stack. Then just laminate this between the other two sticks to form up your mast. Alternate the grains so they don't all end up going the same way in the laminations. The middle board(s) can be butted together at the ends if they are not full length.

This would give you a stronger mast, without plywood center core that will finish out evenly overall. You are going to taper the mast anyway so you will be cutting off excess material from either side. A little more if the center lamination is a bit thicker won't make any difference.

Option 3 Epoxy saturate the edge grain of the plywood before assembly to assure that you don't have any potential void issues in the future.

If you laminate with epoxy, don't clamp the layers too tight and squeeze out the epoxy. Epoxy starvation is a real potential issue in laminations so you want to have the pieces lay as tight as possible before you glue them together. You can use Resin glue and clamp it and it will cure up just fine. Same with polyurethane glues. Most of them are totally waterproof, that is one of the reasons they are recommended for outdoor projects.

There is also another reason for laminating your mast. You have the opportunity to set a channel into it for wiring a mast head light. I would just set in a length of PVC pipe and glue it up. Easy and no worries about potential for water incursion inside the mast and into the wood that way.

[Andrew]

Ken

What a brilliant idea - and what a money saver. I can ask my mother-in-law to do some cooking for me over Christmas

Barry - I'll probably go for 1/2 inch CCX down the centre - and coat it VERY liberally in epoxy - finding good wood round here is a pain!! - On a better note I joined the local wooden boat association today and they have an add for a lumber yard in Sydney (3 hrs drive) that will sell you a complete weekender supply of wood/screws/fittings/sails etc. I might give them a call about masts!

Thanx again to all on the board

Andrew

[Konrad in Lincoln]

I just did what Ken Connors did: Used a 4x4.

I'll tell you from my experiences that the mast on the Vacationer is probably oversized by about a factor of 5. It'll never, EVER break. Unless you flipped the boat and dragged the mast on the bottom or something crazy like that. :shock:

The loads are just too low on this rig to lose sleep over any of this. You could use a ratty knot-filled 4x4 and it'd work and you'd never have issues. The real safety factor of this boat is that it's unballasted, which means you're NOT going to be out in weather that will ever test this rig to it's max design criteria.

But that's actually a very good thing.