New Boom

[ALPHORA]

Woodworkers,
I have to make a new boom for the staysail on our Tayana 37. I have been advised Sitka Spruce is the wood to use. Does it need to be laminated or will one piece be OK. If it needs to be laminated which is the best adhesive

 

[Kukri]

I wouldn't bother with Sitka spruce for a staysail boom; BCP (aka Douglas Fir or Oregon Pine) is just as good in this location and a fraction of the price.

Staysail booms have to be considered as "expendable items", I'm afraid - my 37ft cutter is on her third (in 72 years) - they get knocked about a lot and come into contact with all sorts of things, such as the crew, which is quite soft, and other bits of the boat, which are harder.

Not at all a bad idea to make it from two staves glued together lengthwise if you have enough cramps; if not, I would not be unduly concerned.

Use epoxy unless you are really really good at getting a fag paper fit and
you don't mind a purple glue line, in which case use resorcinol if you can get it - the practical answer is use epoxy - either West or SP Systems. You'll need about a litre, plus microfibres to thicken it.

 

[laurance]

I agree.
Unless your boat is very small and weight's the important thing, or your very wealthy and vain, the toughness of Doug fir is quite likely to do better in this application than a light laminated Sitca spruce spar - loverly as such an item maybe to behold.
Also the heavier DF spar will contribute a little to twist control in the sail, as it does when used solid for main booms in Gaffers without other means of mainsail twist control. This may of course not be relevant to you.
Whether you chose to go solid or laminate will depend on how likely you think your spar will distort of twist, long light spars being most susceptible. Some may also argue that a well made laminated spar is stronger than a solid one but much may depend on the quality of the timber you start with. For a lose footed staysail, if that is what you have, a bit of wobble is probably not to much of a concern.

 

[Tranona]

Agree that Douglas fir is fine. Whether to laminate or not depends on the section and how good a piece of stock you can get. I have a solid spinnaker pole just under 3m long I made from solid Douglas fir, but it is heavy. For a boom I would consider making it T shaped from 2 pieces about 100*25mm. Much lighter and easier to make than a solid spar of the same stiffness.

Glue not critical - epoxy, resorcinol or polyurethane would be OK.

 

[peter radclyffe]

if you can get quarter grained tight growth ring timber, its better

 

[fishermantwo]

I am in the final throes of making a new boom for my quarter tonner. I took the easy way out and bought a black anodised Hobie 16 mast from a scrap metal yard for $30. Cut to length and retained the fore stay tang as the main sheet point.

 

[ALPHORA]

Thanks for all the advice, I will go with a one oiece Douglas Fir as I am not too worried about weight,Dave