Beavers Prize 1777 by Mike Y - 1:48 - POF - Hahn style

[Mike Y]

Winter finally arrived to Stockholm => humidity dropped => some ugly gaps opened between the frames..

(the spacers are glued on the "dead" part of the frames, that would be cut off when the hull would be removed from the jig. The cutoff marks are visible. This glue mess definitely does not belong to the hull!)

 

These spacers were tightly glued previously. As a result, some frames are twisted, leading to uneven spacing

Hope it will return back to norm when humidity will reach the normal levels.

 

I was worried about it, and was thinking of leaving every 4th spacer unglued on one side, to allow for a predictable shrinkage. But discarded this idea as an overthinking. No, it was actually a smart idea. Even with 60cm hull, humidity changes cause problems.

 

On a positive note - it means I have the entire winter to finish the gunports, fair the hull and prepare the keelson. 

I can't install the deck clamps before the end of the winter, otherwise I will end up fixing that twisted frames permanently.

No rush!

Edited January 6, 2016 by Mike Y

[dvm27]

Having a solid wall of timber is probably not the best idea, as I found out on my Speedwell model, Mike. There are gaps between the fillers in the winter. I have filled them with sawdust and glue and they have appeared elsewhere. They'll probably disappear as the humidity rises, as you perdict.

 

I am reminded of the problem Franklin had when building his beautiful model Egmont (which was purchased by the NMM). He noted that his hull shrank almost 1/4" after framing as the humidity decreased. He applied a wet towel overnight and the length of the hull was the full 1/4" longer the following day. He then applied the wales and the problem was solved.

 

if there's one thing I learned after watching This Old House for 30+ years is that wood is a living material that expands and contracts. One must always compensate for this (although I'm not quite sure how this could be done with a full set of filler frames unless the model was kept in an environment with consistant humidity forever).

[Mike Y]

Greg, nice story I guess if you want to make a full set of fillers - some of them should be glued only from the one side. Or buy the humidity controlling equipment? I heard they are widely used by the people who are into wooden musical instruments - guitars, violins, etc. They are a solid objects made out of thin wood, I can only imagine how it will be stressed when humidity changes dramatically.

 

After careful inspection, I found around 8 cracks per side.

Made a symmetrical cracks on the other side too, to reduce the twist and relief the stress in the hull.

Next time will do it from the very beginning. A single-side glued spacer every 3 frames or so.

The whole point of that spacers was to lock frames (avoid twisting and keep a clear 90deg angle) and to have a more solid hull when fairing.

 

Lesson learned! Hope the frames will go back to normal when the winter ends. Reeeally hope so

[tlevine]

There is also the option of running a humidifier in your workspace to maintain a relative humidity of 30-35%.  Doing this in the winter and running a dehumidifier (aka A/C) in the summer made a big difference for me.

[Mike Y]

Yep, tried it. But my hunidifier is too small for that livingroom (it is also an openly spaced room connected with other rooms, I hate doors except for bedroom).

So I need to invest into some sort of apartment-wide humidifying system. Not on the shopping list so far..

 

Also, luckily there is no low humidity except winter - the area where Stockholm is located is between the sea and a large lake, so when this water is in the wet form - it is very consistent medium humidity. With a rare and short spikes up when it is really raining.

 

So I guess it is better to just keep it in mind and prepare the "shrinkage" points, so the hull can shrink evenly without any twists or deformations.

Edited January 6, 2016 by Mike Y

[Gaetan Bordeleau]

The joints on French keel are all  horizontal.

I believe an horizontal joint is stronger because it could support more weight than a vertical joint.

 

 

In french the name is trait de Jupiter.  If you look this title on Internet,  this type of joint is always horizontal.

Edited January 7, 2016 by Gaetan Bordeleau

[Mike Y]

Thanks for the info, Gaetan! It is definitely a food for thought.

 

While cutting the gunports, tested few finishes. Getting tired of wipe on poly - it is tricky to apply (sticky, needs careful buffing, otherwise the surface is not even). Disclaimer: it is hard to find Minwax here, so I use some local brand.

 

Tried tung oil (locally produced, but well respected brand) and some danish oil:

Tung oil seems like the right choice, because it has a boat on the canister, not like some typical "furniture piece" on the can of the danish oil 

 

I use pear for the structural element of the hull, not planking. So I was emulating small surface, but with some edges, milled mortises, etc. It was also important to check how it works with the residual glue (if I used too much glue and immediately wiped the excess away). One coat for all finishes, because I do not want to bother with multiple coats for every single part that goes onto the model.

 

Results:

Left - wipe on poly, center - tung oil, right - danish oil.

Bottom - untreated pear, no finish.

 

Seems like the tung oil is a clear winner. Hard to see on the photo, though.. It is also less glossy than any other finish.

It makes pear much darker though, so maybe I need to try to dilute it. 

Danish oil seems ok, but failed to penetrate the wood properly in the mortises and where the residual glue was present.

 

Also tested how easy it is to scrape away the oil and glue something, just in case I will need to install some part after the finish is already applied. Tung oil and WOP are the winners, because they are thick and do not penetrate the wood deep enough (WOP do not penetrate at all, and Tung oil is easy enough to scrape away). Danish oil is penetrating quite deep, but also possible to scrape away.

Edited January 10, 2016 by Mike Y

[Gaetan Bordeleau]

Tung oil is more refine oil than danish oil.

Tung oil instantly ''age '' the look of the wood. It does not build up like  danish oil.

Very easy to apply, just wipe the excess.

 

Finally, one important reason, when you take a photo, there are no shining spots as you could see often with danish oil.

 

I thought that tung oil was made with tung nuts growing in China.

[Remcohe]

I also did some experimenting, Tung oil, WOP, beeswax, museum wax of different brands.

 

I use Tung oil as a finish, 50% deleted with turpentine. Gives a nice nearly flat finish, not as flat a sanding sealer which I like better. But Tung Oil also takes care of any remaining sanding dust in joints and other very small recesses.

 

Remco

[Gaetan Bordeleau]

Remco,

 

May be it could be interesting to try to go 1 step further.

 

I use 1 coat ofTung oil straight because I like the look of it and it is very easy to apply.

 

2 questions: what is the advantage to go 50-50 with turpentine?

                     does the wood could benefit  from a treatment before applying Tung oil which could help to enhance the final look  when           completed?

 

I do not know the properties of a sanding sealer but I could try a test  2 cherry planks 1 with Tung oil only and 1 with  as a preparation.

 

May be  I could read instructions before applying too to see if they have some good ideas.

Edited January 11, 2016 by Gaetan Bordeleau

[Gaetan Bordeleau]

I hope I do not get too much intrusive, but after a little research, here is what I found.

 

  Tung oil has been known about for hundreds of years in China, where it was used as a preservative for wood ships. The oil penetrates the wood, then hardens to form an impermeable hydrophobic layer (repels water) up to 5 mm into the wood.  In a pure form, the oil is an amber color, and has the approximate consistency of glycerine.   The first reason to oil the wood is to enhance the color of the grain. Wood stability is another good reason. It reduces the rate and amount of water vapor entering the wood so that it does not swell either to quickly or too much. Pure tung will give you a matte finish.

 

Tung oil seeps into the grain of the wood, giving it a perpetual wet look that highly accentualizes the grain of the wood, commonly referred to as "making the grain pop". Because of this, the color of the wood is slightly darkened, giving the wood a rich, warm color that is very pleasing.

 

 

Application: Raise the grain, sand, and then begin.

 

Almost all experts agree that using a cloth moistened with warm water is the easiest way to raise the grain on your project before oiling. When using pure tung oil, you need several coats. It’s very important that you thin each coat with the first coat being the thinnest (I recommend 70 percent solvent). Each successive coat should be thicker (less thinned), and the last coat must be the thickest. Your thinner needs to be an organic solvent, one that is carbon based like turpentine. Every layer except the last must be sanded, so the next layer of tung oil will bond to the previous layer. 320 grit sandpaper creates the “tooth” that grips the next layer.  

 

Sanding sealers are usually used to fix problems with uneaven absorption of stains, however it is not required under penetrating oil finishes such as tung oil. If you do choose to use sanding sealers, it is recommended that you are sanding to 180/220 grit, and only move on to finer sanding once the sealer is applied.   

 

In my case,sanding is below 100, the sanding roller is 80 grit, so I do not believe  a sanding sealer would be any help as long as the kind of wood I use , in this case cherry evenly absorbs the oil which in this case is not a problem. They recommend 3 or 4 coats in the real life to obtain hydro properties. In my situation 1 coat is enough to enhance the color of the grain which is the main reason to use it.

100% pure Tung Oil is slower drying, but this will be improved with thinners. Tung Oil loves to be rubbed, and the more heat generated the faster it dries. This makes it a great "friction polish" for lathe finishing or hand rubbing.

 

The next seed oil that I will try will be grape seed oil which has been apparently used by generations of instrument makers. It has excellent drying nature being high in Linolenic to be a main reason why this particular oil has been used.

[Mike Y]

Gaetan, you are definitely welcome! It is not intrusive at all.

 

Interesting approach. I miss the idea - what is the benefit of raising the grain? 

[Gaetan Bordeleau]

Hi Mike,

 

Depending of the wood species,wood fibers  can rise when you apply a liquid on the surface. We try to eliminate fibers rising before painting so that after we have a softer surface without wood fiber peaks.

[Remcohe]

 

 

2 questions: what is the advantage to go 50-50 with turpentine?

                     does the wood could benefit  from a treatment before applying Tung oil which could help to enhance the final look  when           completed?

 

 

 

Diluting has two advantages. The oil dries quicker and there is less risk of a build up of a layer of oil on top of the wood leaving a shiny finish.

I had no need to apply sanding sealer as the tung oil does not raise the grain.

 

Remco

[Mike Y]

Remco, do you mind a question?

I read in your log that you used to dilute the tung oil with white spirit, but now you suggest turpentine. What is the difference between that substances for dilution?

Is it possible to store a diluted oil in some can for months, or it should be stored in the original form and diluted right before the application?

[druxey]

Tung oil does tend to polymerize in the container once it has been opened. To store it, pour it into a smaller container to avoid an air space or use a small gas canister (designed for this purpose!) to 'fill' the air space above the oil.

 

As for your humidity issue and wood expansion/shrinkage, this is a perpetual problem with wood. One can minimize this by building the hull in low humidity times of year. When humidity rises, things will tend to swell together rather than shrink apart. A finish on the wood will also slow down changes due to humidity. It is no accident that museums and art galleries control both temperature and humidity. I also use a humidifier at home during winter months in Canada.

[Remcohe]

Mike, my mistake. I only use turpentine. 

There is a big difference 

https://en.wikipedia.org/wiki/White_spirit 

https://en.wikipedia.org/wiki/Turpentine

 

Turpentine smells a lot better. I store a batch of the mixed stuff in a small glass jar, it keeps a long time but is does polymerise to the lid. The rest of the oil I keep in an old bottle that is vacuumed with a wine saver.

 

Remco

[Mike Y]

Druxey, Remco, thanks for the knowledge!

Does it polymerise as a film on the surface, that could be later removed, or I seriously need to use the wine saver or a gas, otherwise the whole bottle will polymerise?

Edited January 12, 2016 by Mike Y

[druxey]

I've had a whole container turn to a solid gel, Mike.

[Mike Y]

Whoops! Damn it!

Gone shopping for the wine saver vaccuum pump.

[AON]

might as well grab a couple bottles while you're out there!

[Mike Y]

Hoorray, gunports are done!

Practice is the key, the last ports were made twice faster than the first ones

 

I also changed the lights in the room and working table to a warmer ones, and now my camera switched to some sort of warm mode when in auto. Photos look weird now, need to find how to adjust the brightness settings on the camera...

 

 

 

 

The next step should be fun - hull fairing! Really worried I screwed up the frame alignment, and I added complexity when installed that "iron bolts" that hold the "timbers" together. Which gives a smaller margin for fairing - bolts can't become too close to the frame edge.

[wyz]

While the colors in the photos may not be accurate I rather like the warmer look.  No matter what light you use to illuminate your model it will look really nice.  Ok, scratch the black light and infra-red.  ;-)

 

Tom

Edited January 17, 2016 by wyzwyk

[jose_b]

She looks really great. Congratulations! I like your way of working. 

[Erik W]

Mike,

 

Well done!  The gun ports look great!  Have you had any more low humidity issues?  What part of the build is next?

 

Erik

[Omega1234]

Hi Mike

 

Congratulations on reaching this critical milestone! She's looking great, irrespective of the photo quality issues.

 

I'm looking forward to the fairing of the hull, next.

 

Cheers

 

Patrick

[Mike Y]

Mike,

 

Well done! The gun ports look great! Have you had any more low humidity issues? What part of the build is next?

 

Erik

Thanks Erik!

No new issues, and I unglued one side of every 3th/4th spacer synmetrically on both sides of the hull, so it reduced the hull stress due to shrinkage, and the gaps are now evenly distributed. Should have done that frome the day one

Next is the hull fairing with a very small margins for that. Should have added a bigger margin when cutting the frames!

Edited January 18, 2016 by Mike Y

[Mike Y]

The "romantic" style of photos is due to the new light setup - two warm spotlights 400lm each installed on both sides of the table:

I will probably just use a weaker lamps (200lm opal shade lamp) to take the photos.

 

The hull is covered in layers of the masking tape and is ready for fairing.

 

Getting really used to working on angle, using the vice as a stand to fix the model. Allows for an easy access inside the hull (yes, it is a problem when building upside down), and also easier to work with the sides of the hull.

Dreaming about a lifting table! 

[Gaetan Bordeleau]

Mike,

 

You will never get too much lighting.

To get 200 lumen with a 400 lumen light, you just need to put your lamp on some kind of arm,

you can easily fabricate and back up a couple of feet.

[mtaylor]

Looking good, Mike.  The lighting does give it an "old" look that's interesting.   Use all 800 lumens or better and still don't have enough light.  Maybe one of these days... rip out the wiring and redo all the lighting.  

 

Looking at the photos, I suspect you won't need a lot of sanding for fairing the hull....