Rotten and old mast

[ray275]

Two questions- I have removed both masts from the deck of the renovation of Prescilla K. They have sat on the deck,horizontal, for the past five years therefore dried up I think they are either spruce or fir there are a couple of knots but the main mast is not too bad Question one - How can I check the strength/ soundness before I start cleaning up and revarnish?
The mizzen is smaller and shaped like a pear ( end on) no knots but some rot where fittings are. Question two- Can I scarf in wood to repair and if the rot is deep and then I repair will this weaken the mast?
All donations gratefully received !

 

[georgelewisray]

Unless the spars have been painted it is almost as simple as "If it looks good it is good." One has to be sensitive to the way that water/moisture travels and where it might lay and cause and hidden/disguised problem. If there is no seperation of glue joints and the only rot is very small pockets by fastenings you can likely replace the rot with glue putty of some sort (epoxy?) and sand and varnish and there you go...
A hat pin or some such small thin/sharp probe will help you determine if there are pockets of rot and if so how big they are. You don't want to gash up the spar to much in checking things but a handful of thin little poke holes are allowed.


If rot proves to threaten the structural integrity you can scarf in replacement and that is/was common practice. Use a digital camera and make scale drawings that you can post to a discussion group and you will get some good advice and specific suggestions as to the proper nature ao a full repair.

 

[Peterduck]

As you suspect rot around fittings, try sounding the timber with taps of a light hammer. If the timber "rings" [ie sounds firm] the rot may only be shallow. If the tap sounds woolly or dull, suspect that there may be more rot inside than is visible outside. Fittings are usually at high stress points, so repairs need to be well-done rather than quick fixes. A scarf in a spar is usually done with a compass plane, as it has a shallow curved face between the spar and the graving piece. The axis of the curve would be square to the axis of the spar.
Peter.