Those of you who have followed the epic on the main site will know I have been 're-visualising' an old tatty f-glass N18 into a cruising dinghy with a lug rig.
stunned by the + £1K pricetag for a carbon spar I decided to build my own hollew wooden mast, which is now almost done. It was'nt quite as refined as I had hoped, problems with gluing up meant that some of the external glue lines were rather more open than I had hoped, but the spar is essentially sound and probably overbuilt. I have glued and filled the open gluelines with thickenned epoxy.
The mast will essentially be unstayed, carrying a high peaked balanced lug rig, the deflection on the mast, tested by putting my not inconsiderable bulk on the centre whilst having the masthead and partners supported is around 1" side to side and zero for and aft [the section is ovalish]
Anyway - to the question in hand - Finishing. yes it's the old G4/varnish/epoxy/paint conundrum.
I'll say from the outset that varnish is out. The spar will be painted, whether in 2 pack or trad, I'm unsure, hence the reason for this rather long-winded post.
My thinking at the moment is to either coat with G4 or Eposeal and paint - primer/undercoat, and white topcoat. The topcoat needs to be reasonably long lasting, and able to withstand a certain amount of banging around from the yard [which will be leatherd]. Will trad yacht enamel suffice or should I spring top dollar for 2 pack?
What say you good people?
'Sibrwds' Mast
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Obscured by clouds
- Posts: 715
- Joined: Mon Apr 06, 2009 3:23 pm
- Location: north Wales
'Sibrwds' Mast
Tony
MR 2404 Julia Dream
N18 276 Sibrwd [ongoing project]
Hirondelle catamaran Kalipse
[down to 3!]
MR 2404 Julia Dream
N18 276 Sibrwd [ongoing project]
Hirondelle catamaran Kalipse
[down to 3!]
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Ian Malcolm
- Posts: 51
- Joined: Mon Mar 07, 2005 3:42 am
- Location: United Kingdom
Re: 'Sibrwds' Mast
The mast will probably flex a fair bit if it isn't a ruddy telegraph pole.
Most twopack and other hard paints and even conventional varnish are likely to crack as the wood bends. That's why they used to have a special grade of varnish for spars which remained more flexible. Unfortunately as so few people use wooden masts and spars any more, "Spar Varnish" is just a marketing phrase nowdays and you need to check the manufacturer's application notes. IIRC while B&Q were sponsoring Ellen McArthur, they made the mistake of selling one that was labelled on the tin as "Not for exterior use"!
Sorry that's not a lot of help in finding a product that will actually work for you.
There are some two pack car paints designed for plastic bumpers that are hard but have enough flexibility - talk to your local independent auto spay shop, they aren't DIY as the fumes are highly toxic.
There is nothing to stop you using a different harder paint where the jaws bear. You might even want to surface this area with glass or kevlar cloth. before painting.
Most twopack and other hard paints and even conventional varnish are likely to crack as the wood bends. That's why they used to have a special grade of varnish for spars which remained more flexible. Unfortunately as so few people use wooden masts and spars any more, "Spar Varnish" is just a marketing phrase nowdays and you need to check the manufacturer's application notes. IIRC while B&Q were sponsoring Ellen McArthur, they made the mistake of selling one that was labelled on the tin as "Not for exterior use"!
Sorry that's not a lot of help in finding a product that will actually work for you.
There are some two pack car paints designed for plastic bumpers that are hard but have enough flexibility - talk to your local independent auto spay shop, they aren't DIY as the fumes are highly toxic.
There is nothing to stop you using a different harder paint where the jaws bear. You might even want to surface this area with glass or kevlar cloth. before painting.
Ian Malcolm. London, ENGLAND. (FORUM REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.
Re: 'Sibrwds' Mast
Check that the product you get has maximum UV protection. Epoxy is not great for UV resistant so needs protection. ( Good old aerolite is often preferred for spars as it has much better UV endurance)