Raw or boiled linseed?

[Steveh]

http://www.imagestation.com/picture/sraid164/p62c5bc89f83142adf7c7dc85270a6232/f48b0c47.jpg

As if I need the work. What with Ngatira progressing slowly and a Yanmar to strip down and decide weather to rebuild or use as a mooring ;) .

But I do get the urge and find myself down in the car port with enough time to strip a plank (strake) give it the thrice over finishing up with a mix of 50/50 terps and boiled linseed to feed the wood.

And of course this is the time when you look at those glowing planks and think "mmmm that would look superb varnished"

So the point in question is what is the better of the two? Raw or boiled. As I understand it boiled dries harder than raw but is this the best to prepare for varnishing?

[seayou77]

The Raw goes black, say inside the hull. I had some shellac I tried to cover, didn't happen.

[Jay Greer]

Well now! You can save yourself a heap of time and get a very good job by just thinning out your first coat of varnish by about a third with pure turpintine. It smells good. Goes on easy. Soaks in, seals the wood and drys a hell of a lot faster than linseed oil which, in fact is not necessary---at all! That is unless, you are going for an oil finish instead of varnish.

[Wooden Boat Fittings]

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What Jay said.

However....

As the owner of a bright clinker dinghy myself, I can tell you that keeping the varnish up to the mark can become a chore (especially if you leave her in the water all season.) If you like being able to see the wood itself but can do without the high gloss finish and all the upkeep that varnishing requires, you could do worse than consider oiling her only. Oil can be slapped on a bit at a time, whenever you feel like it. It doesn't need any preparation. And it doesn't matter if you do only a strake or two every other week. Or month.

Mike
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[Bob Smalser]

Boiled linseed is simply raw linseed with metallic driers in it. Raw linseed takes a long time to dry properly and larger quantities soaked into end grain never dry.

Both flavors turn black in UV:

Original boat soup finish:

http://pic3.picturetrail.com/VOL12/1104763/2594266/32745994.jpg

Finish one year later:

http://pic3.picturetrail.com/VOL12/1104763/7081299/91841729.jpg

Applied thinned and hot, it's useful to soak into old wood that's become dry and brittle before varnishing, and soaked into raw plywood it'll aid in preventing it from checking.

I'd repaint that boat, leaving some varnished trim, as paint simply provides better and more durable protection. If you do want to oil it then commercial linseed-based finishes like Watco, Seafin and the like don't turn black in UV.

[Ed Harrow]

If you take a look in the WoodenBoat archives, you'll find an article by Paul Haley advocating the application of linseed oil (and no, I don't remember which) to wooden boats when they are hauled out for the winter. His point was that it helps to stabilize the wood.

Similarly, Poppie's tool box, which was tweaked for years (thanks, Dad, LOL) was straightened by soaking with linseed oil, careful disassembly, reassembly, etc. The linseed oil allowed the dried wood to be coaxed back to shape.

[JormaS]

I agree with Bob, including painting in stead of varnishing.

As for boiled linseed oil, it is raw oil boiled at 180 centigrades for a certain amount of time, with driers added. The oil starts polymerizing (molecules get bigger I guess) and the oil won´t soak into the wood as readily and thus can be used like a varnish.

If you want to impregnate the wood, you should use raw linseed oil. It takes from 4 to 6 weeks to dry which means that it has a lot of time to find its way into the wood. Very efficient, and it is done a lot in Scandinavia - an old tradition. The oil will make the wood swell somewhat initially, and in the coming years it will stay rather stabilized. If, after this treatment, the boat has leaks when you launch it you have to consider that the wood will take up water very slowly.

The wood will darken somewhat, but if it gets really dark or black it is because of molds and dust etc.(maybe ultraviolet also). The oil doesn´t really have to be thinned, but I usually add some 20% of pine turps or something which contains anti-fungus poison because of the mold problem.

This is time-consuming because you have to apply the oil once or twice a day as long as the wood absorbs - which can go on for two weeks if the wood is old. Then you wipe off the oil that has not absorbed and after that you do something else during the next few weeks. Then you can paint the bilge with read lead paint for example.

The rest of the inside you can paint with boiled linseed oil, which will make it look very professional. The real reason is that it is easy to maintain. Paint on the inside is a bad idea because it will flake, and you´ll regret it.

On the outside you should paint the hull with ordinary oil paint (house paint) because it will hold on for many years, and even after that it is very easy to maintain. If you can´t find it you can mix titanium white pigment into boiled linseed oil and there you have a cheap high quality oil paint.

This is how we do it. But we´re a lazy bunch trying to avoid work whenever possible, and we have discovered that if you do it right once, you can concentrate more on fishing and sailing. ;)

[Wooden Boat Fittings]

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Which reminds me that to waterproof a leaky dinghy, Eric Hiscock recommended putting some gallons of linseed into the interior, then moving the boat round on chocks bit by bit till the enitre interior had been thoroughly soaked. He said it provided a permanent cure.

Mike
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[Steveh]

Thaks guys, that’s excellent. My main reason of using linseed is really to feed the wood. As for varnishing I’ll think on that. Either way it will be finished with paint or varnish. Don’t really want a mouldy black boat.

Sailing the other day onboard Rawene (see Lohn B thread in Misc. Boat Related A sail on a special boat. Rawene. Page 3) the owner’s grandfather designed the NZ version of the frostbite and talking about them discovered one of the crew used to own the frostbite I now own. Useless trivia, but said crew also oiled interior as Hiscock described but using DEKS OLJE. I think this might be a linseed based product too. Sounds like a good option seeing I’ve started with the linseed.

[Wild Wassa]

Deks Olje (from Flood) comes as Deks #1 a matte finish and Deks #2 very glossy. It is recommended that #2 be painted over #1. I like satin so I mix 50/50 (or adjust to suit), over 4 coats of Deks 1. Allow an adequate curing time because Deks stays soft for a while. If you do blend 1 and 2, mix only when needed ... because they will set in the jar when mixed.

I rub Deks onto spars with my hand (watch out for splinters though), I don't use a brush with Deks, pour a bit on and rub it in. Deks Olje needs the skills of a finger painter (just like in kindergarten). You either like Deks or hate it. Deks is softer than varnish and needs doing more often but is so easy to apply and redo ... it isn't as though you have done anything at all, unlike varnish.

As a painter, I use refined Linseed at about 4-5x the cost of the par boiled or raw and add oil rich drying media, (types 1(fast), 2 and 3 (is the slowest and most flexible and used for topcoats). I use refined linseed because it has no artefacts in it and it doesn't darken as quickly as the basic linseeds.

Warren.

[ 04-11-2005, 02:57 AM: Message edited by: Wild Wassa ]

[Wooden Boat Fittings]

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I've read a good deal in these pages over the years about linseed darkening. But where I am, at least, I haven't experienced it (except by its attracting dust while it's still wet.) My experience would lead me to believe this is an overstated drawback.

It was Deks No.1 that we used on Swallow's mast (http://www.woodenboat-ubb.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=3&t=001932&p=), and this was the first time it had be redone since new, three years ago. Being an oil, it's easily applied, as Warren says. (It's also sticky however, so you don't want to splash it around the general environment too liberally. By the way, for more pictures of Swallow, see this page (http://www.woodenboatfittings.com.au/forsale/forsale.htm).)
_______

Hey Warren, what's your email address these days? I'm not getting answers from the one in your Profile.

Mike
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[ 04-11-2005, 10:18 PM: Message edited by: Wooden Boat Fittings ]

[allwood]

I sure like tung oil as a linseed substitute. That is unless you want the coating not to dry (raw), don't mind the darkening effect (boiled and raw) or really need to save a few bucks.

[Wild Wassa]

Originally posted by Wooden Boat Fittings:
"My experience would lead me to believe this is an overstated drawback."

http://www.imagestation.com/picture/sraid164/pe52e9532e35530fd4de53bc5966cb4e9/f47b8a56.jpg

When it ages slowly you can't see it happening. This bottle is only about 3-4 years old, the residue around the cap, is a bit dusty but not 2 stops dusty (I'm guessing 4x darker desitometrically speaking). Twenty years of build up would be awesome.

Refined Linseed is a quality product.

Mike I'll give you a call my email doesn't work, Microsoft keeps failing to accept my Windows XP as being mine. The dramas of changing a motherboard as far as Microsoft is concerned. I can't reinstall Canon's twain drivers to get access to a few bits either. Microsoft tells me my XP is an illegal copy, a $700 authentic Microsoft illegal copy ... as weak as water.

Warren.

[ 04-13-2005, 04:12 AM: Message edited by: Wild Wassa ]

[Canoeyawl]

I have a suspicion that raw linseed oil is a favorite food of the wee bugs. My experience is that mold/mildew loves to grow on wood coated with it. At least boiled linseed oil has some toxicity...