Good Excuse Needed

[garethrow]

Can anyone give me a good excuse / reason or two for temporarily 'storing' my wooden mast / boom etc in the living room please? She who must be obeyed may need some convincing of the need to circumnavigate the Christmas tree with a minor detour or two.

I have swapped from Rustins to  Sikkens Cetol Filter 7 this winter and I am having to wait rather longer for each coat to dry than I would like when confined to the workshop.  - So, thinks I - what about all that lovely dry warm space in front of the wood stove? Hmmmmmm.

By the way - good to see a collection of SBs signed up to Seafair Haven 2016.

All ideas gratefully received!

Gareth Rowlands
Gwennol Teifi S17

[Graham W]

Woodpeckers.

[Rob Johnstone]

But might it bring in woodworm?

[garethrow]

Woodpeckers?  Woodworm?? Minimalist Christmas tree?  Foresooth folks - I am doomed, I have had to resort to bribery. I am not sure the laundry will be quite the same again though...

I wonder if I am the only one who has this type of problem?:

a) Bits of boat in the house
b) Seikkens taking ages to dry - particularly the first coat. I am putting on top of sanded Rustins - but this has worked fine on other parts of the boat so I am puzzled why the mizzen mast won't dry. One or two bits did take a while for the first coat, but went dry after 2 days at 50 - 55 degrees F. This mast however has been tacky for 5 days now.

Regards

Gareth Rowlands
Gwennol Teifi S17

[stef]

If the family situation becomes really critical ...
a gardening tunnel in the garage with a forced air heating on timer is impeccable.
tested with a 2 second tent for parts carbon epoxy.
otherwise the fire is not far ... 
Merry Christmas.

[Rob Johnstone]

Re the drying time; me joints tell me it's been terrible damp in Bucks for the last few days - could it be a humidity problem?

Rob J

[garethrow]

Coluld well be Rob - does humidity slow down drying time? If so I am hoping that the living room stove will resolve in the not too distant future

Gareth
Gwennol Teifi S17

[Peter Taylor]

does humidity slow down drying time?

Very much so!  Most paints and stains nowadays are becoming water based so drying depends on how quickly you can evaporate water from the painted/stained surface.  The evaporation rate depends on the air flow over the surface and the humidity deficit in the air. 

The humidity deficit is roughly the difference between the amount of water vapour held when air is saturated at the temperature of the drying surface (measured in g of vapour per kg of air, which is almost but not quite g per cubic metre) and the actual amount of water vapour present in the air blowing over the surface. If you use an instrument to measure the humidity of the air you will probably get a reading of relative humidity (as a percentage).  So if you measure say 75% relative humidity the air already is holding 3/4 of the maximum amount of water vapour that it can hold.  So you have a chance to add at most a further 25% while getting your mast to dry.  Of course if the air is moving, then you can keep adding water vapour to it because the air that you have moistened will blow away.

But there's a catch. the actual amount of water vapour in grams that that 25% represents varies very rapidly with temperature.  If the air is cold, that 25% of relative humidity may only represent a gram (per kg) or less.  Only a little bit of the stain or paint you've added can evaporate before the air is saturated.  If the you are at tropical temperatures, 25% may be 10 grams or more and things dry more than 10 times quicker. 

Summary: warmer, drier, faster moving air hastens drying.

Incidently, the rapid increase in the amount of water vapour that the air can hold  at temperatures of 30C and above, is why climate warming of only a degree or two has the potential to make weather much more extreme.  An example of this effect is that hurricanes only form if the sea temperature is more than about 28C.

End of lecture! Happy Christmas,
Peter

[garethrow]

Thanks for your detailed explanation Peter and your season's greetings.

I hadn't realised that humidity would have such an effect on Siekens - which I assume is not water based as it requires white spirit to clean brushes. However, in my case I think the problem lies in water penetration into the timber that is not obvious to inspection / touch. If humidity were the cause of poor drying (and heaven knows- it's certainly a bit damp around here in the west) - then presumably the whole mast would remain tacky; as it is, it is just one or two spots that remain stubbornly tacky. I have now stripped these down to bare wood again and applied a heat gun in an attempt to drive out any damp within.

At this rate it would be considerably quicker to make a new mast from scratch!

Regards

Gareth
Gwennol Teifi S17

[steve jones]

Happy New Year,

I found the dying time using Danish Oil on my BR17 to be around 2-3 days during Feb2010, in my unheated garage. Jan/ Feb 2015 I used Sikkens Cetol'7  on the mast and spares of my Cornish Crabber, again in my garage and the effect was the same 2-3 days touch dry time, however ,at the same time of year I applied Sikkens to the woodwork on the Crabber in the open air and the drying time was about a day. At the moment I am painting Sikkens , on components of the boat in my garage ,the drying times are back to 3 days or so.  Make of it what you will !

  Hope to see you at Seafair'

Steve  BR17 Nona Me

[garethrow]

Thanks Steve, and a Happy New Year to you to.

Very interesting comments. I will try leaving a little longer in the garage but as I said in earlier post - the drying is not even - some bits of the mast are fine whilst others remain tacky. I have tried striping down to bare wood and starting again with Siekkens - and am waiting to see the result. It is however very damp here at present. I am wondering if I have salt water impregnation into the timber in places and if I actually need to soak the mast in fresh water for a while - which seems rather counter intuitive when I have spent around 3 months trying to dry it out properly!

Yes - should see you at Seafair Haven in June. I wonder if it will have stopped raining by then?

Regards

Gareth
Gwennol Teifi S17

[steve jones]

Hello Gareth,

  I am still experiencing that patchy , uneven   first couple of coats in the  garage, which seems to cover  ok after a few more coats. I recently fitted two oak sampson posts on the stern of the crabber, initially first coat at a home and then final on the boat, -same result :-patchy in garage  but ok in the open air in the between rain .

 I've  now used the Sikkens on pine, mahogany and oak with the same result. I haven't tried contacting the manufacturer as it seems to come right in the end.  Never used it on Douglas fir though, I decked the BR with DF and used Danish oil securing and calking with Sicaflex.
 A marine paint I have discovered is Jotul  is mail order only  and is supplied with a minimum of 5 ltrs
it is designed for big ships! ,suberb paint though.

Regards

Steve

[garethrow]

Hmmm, interesting Steve. Yes I had also noticed that if one can get the 1st couple of coats (Siekkens) to dry, subsequent ones behave better. Did you detect any pattern to the patches that were slow to dry - harping back to my salt water impregnation theory?

Regards

Gareth

[steve jones]

   Initial patches occurred on the internal mahogany panels, there didn't appear to be any surface expression before hand, similarly with the mast and spars , and the oak stern posts.  Outside  painted stuff did dry with different densities but I can't remember any of the obvious patch pattern.
   I chose Sikkens for its UV properties and because the Crabber is out on the pontoon all year, I like Danish oil but noticed that other boats at the yacht club require constant attention. The BR spends a lot of time in a shed. Expensive varnish, like Coelan? I rejected - it's a boat not a piano! and the cheaper stuff would not last long here.  I also have a Tideway that requires the awful varnish taking off and oiling ,but time  is the enemy.

Regards,

Steve

Steve

[Matthew P]

I have tried various finishes on various boats over the years.  With no technical knowledge and probably inconsistent application I have found:

Conventional yacht varnish - looks great but there is not enough time in my life for all the sanding, multiple coats and maintenance.  I do admire those lovely boats when it has been applied well though. 

Burgess Woodsealer - at one time beloved and recommended by Drascombe owners. It's weird watery stuff, but easy to apply and seemed effective at preserving bare teak.  I felt I had to apply at least one new coat each year.

Deks Olje -  it is satisfying to apply, I like the smell, (maybe I am becoming addicted) and newly applied looks good to me.  But again I feel the need to reapply it at least once a year.  Its the devil to get off fibreglass gelcoat if you spill it or let it run - which it does very easily. 

Sikkens was OK but too orange for my tastes.  Perhaps the orange colour results from a high iron or chemical additives that explain its reputation for good UV resistance.  Gladys spends most of her time under a tarp on a trailer, so UV resistance is not a priority for me. Applying it was OK but I do seem to remember it took a long time to dry in winter, in my unheated garage.

International Woodskin (made by Graham's favourite company? - or is that BT or MegaMarine Superstore?) - My current favourite. It is easy to apply and seems quite durable.  I sanded back all my spars and teak on the hull before applying. Cost about £18/0.75 Ltrs.  Some web sites say it takes a while to dry but I've had no trouble outside above 12 degrees C.

Matthew
BR20 GRP Gladys