Glue - advice please

[PaulJ]

I recently bought a "middle aged" Norfolk Smuggler, knowing that it needs a fair bit of tlc....... including a new mast. She is Gaff rigged with a wooden mast. This is the first boat I have owned with wooden spars and having weighed the pros and cons with the yard, we have decided to build the new mast from Douglas fir. The question though, is which glue to use........

The options would seem to be Cascophen, which may leave a dark line at the joins, epoxy which I am told is susceptible to UV or polyurethane........

What would the panel advise?

Thanks,

Paul

 

[DownWest]

Epoxy would always be first choice. The U-V problem is only likely to happen at the extreme outer part of a glue line and paint or inhibited varnish will stop that.
Resorcinol resin requires high clamping pressures, not always easy on a mast. Have you looked at birdsmouth construction?
The guys who built a very big stick (150+ft) for a classic yacht, used a type of urea formaldihyde glue, a bit like Aerolite 306, which is still available from Axminster and others.
Personally I used époxy for all my spars and the birdsmouth method. Doing some more soon, a 23ft main mast, plus other sticks and will use the same methods.

Good discription of B/M on the Duckworks site.
DW

Polyurethane is not as strong as the others, but probably still stronger than the wood.

 

[Seanick]

Cascophen or polyurethane, or epoxy.
Cascophen requires high clamping pressures and a good fit
Polyurethane requires medium clamping pressures and a good fit.
Epoxy does not require much pressure, has gap filling qualities, which is why it's such a DIY favourite, especially if you don't have 25 cramps to glue the mast up!

Whatever you glue it with treat it to real varnish, not some microporous rubbish.

 

[PaulJ]

Thanks both for your replies. DW, I looked at BM construction on the Duckworth site but I think it is a bit too complicated, also the Smuggler's mast is on a tabernacle so the base is square in section and needs to be quite "chunky" so I think we will use a more conventional construction. My main concern with epoxy was it's reported vulnerability to UV but I was not aware that "UV resistant" varnish could help in that respect. The guy in the yard who is going to build the mast does favour epoxy (and I'm not sure how many clamps he has!) so, for better or worse, I think epoxy will be the way to go.

Thanks again,

Paul

 

[TQA]

Large Jubilee [ hose ] clips work well as clamps.

 

[DownWest]

Large Jubilee [ hose ] clips work well as clamps.

+1 That's what I used for my mast.

Paul, the BM system looks a bit of a hassle, but in practice is not. I used a router table with a 45 deg jig, others just use saw tables with guides. For gaff rigs with masts that only taper above the hounds, also easy to do. I ran all my staves down in an afternoon ( locally available timber required scarf splices in all pièces, another advantage of the idea) As for tabernacle, a few extra 'wedges' on the foot sorted that out.
In the end, if your guy in the yard is building it, then his opinion is what matters.
DW

One ends up with a mast that is as light and strong as a practical method can do.

 

[vikramsuri]

nice one