Monday, December 26, 2011

Applied Archaeology

First let me say that the Christmas season has had me too busy to blog.

However I did the repair work in my spare time and photographed the steps as usual as the work went along.

I have seldom done super glue crockery repair on so broken a piece, but I approach with a fearless good old times scientific attitude.

The only tool needed for the assembly tricks is an erasable marker pen. Clamping is hand pressure for ten seconds.

I protect the work surface with a small piece of plywood to take any spills of and provide a better contrast for the photography.

Here I am stuck between a crock and a hard place.

Problems to the left of me and problems to the right of me.

Let me explain.

Crockery does not bend, nor can it be carved, stretched or otherwise fooled with as if it were metal or wood.

Take a look at the gaps in the crockery where the next piece would have to go if I had started glueing it together just anywhere like in a jigsaw puzzle.  The problem will be to do the jigsaw puzzle trick first to determine which pieces go where, then plan an assembly sequence that makes sure there is a way to insert the next pieces where the next piece does not have to slide into a narrow space, or fit into a space more closed at the entry point.

First I sort of assembled the whole thing dry and marked where the various parts met so I could make a swift positioning after the glue was applied.

This shot shows the first actual glued bit. Notice that the angles where the next bits have to arrive are wide and allow easy insertion.

To the right you see the most difficult sequence laid out ready to be attached.

Its an awkward set of small pieces that were at the point of impact I suppose and took the most energy.

Their unique shapes overlap in a way to make the assembly critical. Take a look at the assembly before it is installed on the crock.

The big bit with the handle can go on next but never before because of the way the top rim has to be assembled. There is quite a wide oblique surface that meets on the inside of the crock and it must have the meeting pieces already in place before it can go on.

After gluing the five pieces to the right, I went away for a few hours to let the glue set up thoroughly.

As a note, take a look at the inside. If I were serious about making the crock strong enough to use as, say, a planter, I would reinforce it from the inside.

There are plenty of ways to reinforce the inside of an opaque object.

I have some kevlar cloth and even some carbon fibre I could paste to the inside using epoxy.

Cheaper would be epoxy and canvas or fibreglass from an automotive body repair kit.

Even a coat of varnish under and over some cloth would make a big improvement, and all these would make the crock hold water again although it would not be suitable for cooking or maybe not even plant roots depending on your choices.

So there we have it with all the bits back together and it is still missing a few parts that were missed by the broom.

It gives me an appreciation of the archaeologists who sift through the midden of some thousands of years old village to put together examples of long disappeared pot designs.

This one is not rare enough for a museum to do that sort of thing to but has been a fun time to see what can be done in a small scale exercise of the real thing.

What am I going to do with it?

First its going to be a piggy bank and collect loose change. When its full it will be more valuable.

As a planter it might be interesting to use the tiny hole you can see below as a place where a baby plant can escape to contrast with the big one in the top.

Maybe I'll bury it deep in the park on Mount Royal filled with two quarts of carefully selected odd stuff to puzzle archaeologists of the distant future.

Unfortunately the good side is not the side with the crown, but such is life.

You can't fix it if it ain't broke, and if the fix ain't perfect, well it was broke anyway.

Monday, December 12, 2011

This Old Crock

First I am going to tell you a little (mostly true) story about this picture, and then in my next blog I am going to report on my efforts to repair a piece of broken pottery.

Here's the pic:

I live in an apartment owned by this nice septagenarian guy with a deep tan and a pony tail.

He is surprisingly, still upgrading the building and has progressed from new lawns and polishing the marble in the entry to replacing the electrical panels in everyone's kitchen.

So one day it was my turn and there was this nice electrician - lets call him Mons. H. Dumpty - working away when he accidentally knocked against a shelf and the antique bean crock had a great falling out with its mirror neighbor.

Natch, the Humpster denied everything, and so did the landlord.

So there I was with a sense of doom after sweeping up the cheap recycled mirror that also fell (looking forward to seven years' bad luck) and contemplating what to do with my valuable, way more than just cracked, pot.

Since you can't fix anything that isn't broken, this is an opportunity to repair broken pottery and pass some lessons and experience on to you. It was also as in many seeming disasters, a primo shopping opportunity.

I raced out to the hardware store and got some strong glue for the assembly bit, and a box of vinyl gloves to wear while handling this dangerous stuff.

I selected a fairly rapid setting variety (10 ten seconds) and am now going to do a bit of thinking. Mostly about the best sequence to gather up the broken bits and stick that collection of dumpster destined crockery back together again, thus saving the world.

No king's men and no horses will be used or tested upon in the project.

Not even for making the glue.

I will be using unnatural, chemically produced and somewhat hazardous ingredients.

But hey - its for a good cause; saving space in the land fill.

Thursday, December 8, 2011

waxing antiques

Here is a bit about what wax can do as a finish, and why I prefer to use it.

I prefer it because it is relatively cheap, reversible (comes off with household solvents) can be tinted an amazing number of colours, is water resistant, and easily repairable, while imparting a fine gloss, and protecting the wood from changes in humidity.

See my kit above?

Currently there are three kinds of wax to use according to the application in mind.

You can also see a coffee pot heater that produces a steady temperature of about 140 degrees (I measured it one day) and it will comfortably liquefy a can of wax if I want to blend stuff into it.

There are also a variety of brushes adapted to applying or polishing the wax. I also have a converted floor polisher for large surfaces like tables ( not shown.) You are allowed to modify tools.

Speaking of modified tools, there is a modified spoon/can opener where I ground the end of the spoon handle to make a convenient can opener for the cans of wax, where it does double duty as a scoop for the whole ball of wax.

Here is the whole ball of wax on wax application:

I bet you thought it was just an expression. But no, the manufacturer gives directions on the label  on how to get the best results.

To the right you can see the spoon opener ready to go to work.

Most manufacturers want you customers to get good results so you will come back and buy more , so they print the best clues they can on the side of the product.

One way to tell if the item is made by an American company is to see the Legal Department's wording. READ and UNDERSTAND THESE DIRECTIONS!

I do my best, but I assure you from teaching in a high school that the majority of readers on many tests fail to understand the simplest of directions. Like - where to put their name and the date, for instance.

I digress.

The directions are to take a piece of cotton or wool (never use synthetic fabrics for these tasks) and scoop out a quantity of wax from the can into the ball. I use the spoon opener to scoop.

Then wrap the ball with a thin cotton.  It forms a ball.  The ball of wax goes with to the next step.

Now you can see the relevance of the industrial strength (looks like a hair dryer) variable speed and temperature air blower in the photograph. (Do not dry hair with this baby, it can produce temperatures of over a thousand degrees.)

In theory the ball of wax is warmed by the hand holding it, but I cheat. I set the blower on low and use it to warm the wrapped ball of wax in my hand, and it will dispense a very thin film of wax on whatever I rub it gently upon. No need for great pressure, and I love the fine beeswax aroma coming off as I wax on.

Allow an appropriate time to pass (according to that label) and then polish. I use lint free cloth or brushes depending on the surfaces and the wax involved. You can even find brushes made from  ostrich feathers for polishing wax on antiques, if you live in France.

Here is a method of recycling old belts from bathrobes if you have lots of rungs and spindles to polish:

Wrap the belt one time around the spindle and saw it back and forth, tugging lightly.

With practice you can make it slide up and down as it goes round and round.

For the flat surfaces I use a smooth rag from an old cotton shirt.

Below is a nicely blurred shot of the finished chair, waiting for Godot.

Did I wax poetic?


Tell me what you think, what do you want to know, and I will see if I can do that in the next posts.

Tuesday, December 6, 2011

That Antique Wooden Kitchen Chair Again

Remember in the last post where I said I adjusted one of the back spindles on the antique Windsor influenced kitchen chair with the broken seat?

Because it was too short I said I coped by putting a spacer in the bottom of the hole in the seat?

I lied.

I didn't do it.

But it was in a good cause.

That post was going to be too long and might have become too confusing to mention two other ways to deal with that problem at the same time. So I wrote about the easiest, lowest  tech method first.

But there are other ways.

I deployed my wood stretcher machinery and made the spindle longer using one of two possible approaches.

Take a look to the right.

The spindle is seated deep in the chair seat out of the picture to the left, and I am just finished slicing a flat spot on the side where it will do the most good.

I am doing it this way, with the chair already assembled because you can always do this trick while the chair is apart and it is even easier to do the work to make the spindle effectively longer.

But if the chair only has the one or two problems like a short spindle? Why knock the whole thing apart to make one small repair?

This trick can also work with a broken rung in an otherwise sound chair.  Merely remove the broken bits from both ends, and make a two piece rung to fit, gluing the rung together along a long diagonal cut you pre make, so the ends can be fitted properly and the sliced cut can be glued later.

Here I clean out the hole with a small chisel, and whittle a small plug to fit the hole in the hooped back.  Now do you see why I selected the side away from the place where the hoop curves down? The short spindle can still touch the hole edge on one side so the stress on the glue joint will be less in the task of keeping the spindle in place.

The plug is flat on the side that touches the spindle, and rounded to fit the hole.

It is cut from a scrap of oak. Suitable for this type of service, it glues better than maple, and is strong and shock resistant.

See how the spindle will catch the outer part of the hoop and reinforce the joint?

Now I am going to select a glue for the task of keeping these parts together. In this case, the hoop is flexible and so is the spindle so there will be a fairly frequent testing of the joint, and I do not want a strong, but brittle joint like I would get with hide glue. In this case I actually prefer a strong glue with a bit of creep possibility if the humidity of the location changes from season to season.

So, I am using a cabinetmaker quality white glue whose strength is advertised as above even that of hide glue.

With the glue spread where I want it to be, I tap the little wedge home, using technology from the Bronze Age. A lump of bronze that is conveniently heavy, fits the hand nicely, has a round surface, a flat surface, and even a leather covered surface for imparting small urges with a personal feel.

I follow this up with a small c-clamp that holds everything where it aught to be until the glue sets.                                                This glue has a rapid grab and sets to about 90% strength in about half an hour.  
Now you finally get to see the real last assembly portion of repairing this chair.

My next post will be a peek at the way I wax this piece of furniture. 

Plus as an added bonus I will show you how I operate the common random orbital sander. 

Or maybe I will do a review of mankind's oldest tool so you can see how far we have slipped from the optimum design during the last century. 

Wednesday, November 30, 2011

Over the Top

bent things going straight

The glue is dry and the bottom is assembled, so here I am trying the final bits dry before doing the glue part.

If you look at it above, there will be some fitting problems because the left side verticals are a tad short when they are seated all the way down their respective holes. And, how will I hammer the bent bits into the holes without making marks on them?

The solution I plan to use is merely to not seat the verticals all the way down. I can do it by dropping a short spacer into the hole to prevent them from going all the way to the bottom.

It is the tight fit at the sides that does the glueing, and the fit is good. So I will sacrifice some strength at the bottom to get some at the top.

The other thing to see is how I plan to tap on the curved hoop to seat it in its holes on both sides. It is so springy that normal tapping on the centre  of the curve will not work well.

Here is a closer look at the hand screw type of clamp which is very useful as well as being extremely powerful as a clamp. The two handles allow the top bit to spread the outer ends, closing the gap with great force at the hinge part.  Makes a good nut cracker too.

You got the glue tutorial in the previous posting so I am not going to repeat it here, just remember that I planted the four sticks in the middle and waited for the glue to dry before going on to the hoop part.  Patience is a real virtue in wood working. The ability to pay attention to details and plan ahead is also crucial. But the real test of skill is in how to cover the mistakes.

As Howard I Chapelle wrote in his book about building boats, you need a Moaning Chair to sit in  while thinking of how you did it and how to recover gracefully.

Here is the hoop and its little wedges ready to install. See how much closer the ends are than the holes they will occupy. Its quite springy.

So there it is - assembled and glue dry with the wedges sticking out from the bottom, where I merely saw them flush with my nice Japanese razor saw.

And with the little curved braces installed it is ready to finish.  For a project like this I prefer to use a traditional finish, not the factory one. I first rub a few coats of linseed oil on with some fine steel wool. Then I wax it.

A few clues about using linseed oil are appropriate here.  Its cheap, edible in the raw state (used as a cattle laxative) and bio degradable. Don't use that stuff.

Use the boiled linseed oil which is more suitable because it polymerises to a film instead of remaining permanently sticky like the raw stuff does.

The next clue is that as it dries, and the chemical reaction to oxygen in the air takes place, it puts out heat. Hence the warnings about oily rags. Its the linseed oil that's the usual culprit.

It suffices to either place the rags in a water filled container as per the techno sophistoes, and then contend with all sorts of storage problems and mess when it is time to throw out the garbage.

Or do it my way. My way is too easy and really cheap.

Lay them out to dry flat. (I lay them on the concrete floor overnight, but really any surface will do.)

Or hang them on a line, flat. The heat has plenty of area to radiate from so it never builds up. It is as thermally safe as the oil drying on the wood you just oiled.

For a fire you have to scrunch the rag up into a small volume where the heat cannot escape easily and there is a supply of oxygen for the reaction to take place and eventually the heat builds to combustion temperature.

In my shop I once tested this and a tightly folded oily rag began to smoke after about four hours, so we flattened it out and it cooled right down.

Tuesday, November 29, 2011

Putting the Chair Together Again

Here is the long and the short of it. And get ready for a long post.

It is unnecessary to mark all those little rungs and so forth because they can only fit properly back together one way. (Mostly)

There are two usual ways to make a chair.

One design has a frame that has the back two legs continue from floor to the top of the back, and a series of horizontal parts make it look more or less like a ladder, then there is a frame going forward to connect the front legs and support the seat. The seat can be integral as an upholstered cushion strung on bands of material attached to the frame, or an applied seat that rests on the frame.

This chair is the other kind.

This kitchen chair has a strong seat, which is the meeting point and holder for the back and the legs. It is similar to the centuries older Windsor chair style with a thick pine seat holding the legs and the back, which are usually made with maple and hickory or ash for the bent bits.

In this Quebec made piece, the thick pine seat is replaced by a thinner maple one of the same strength. The rest of the design is simplified but essentially identical to a Windsor, which is considered by many to be the apex of design using different woods for their unique properties in meeting the demands of a chair.

Take a look at the chair from the side. See how the seat slants to the rear for a more comfortable angle. More modern than the Windsor, the seat is made from Maple and carved by machine to that gentle contour that receives the grateful fundament as my grandmother called it.

 Maple is strong enough to do the work while being thinner. (Unfortunately, Maple is harder to glue than pine as it is so dense it absorbs little, and presents a smooth surface which is poor for grip.)

Note also that the legs are splayed out, farther apart on the floor than they are at the seat.

This means that the bottom rungs are longer than the top rungs. Which also means there will be a pair of long ones and a pair of short ones,  and then three extra.

The shortest extra will be at the back because the rear legs are closer together than the front ones. The two left over go to the front, longer one at the bottom shorter at the top. Simple, really.

Also note that the front legs are not only longer, but have some decorative turnings. Maple is excellent for turning and makes good legs and rungs.  Also some fancier chairs have the front rungs turned fancy as well.

Now lets fit some round pegs into round holes.

First look at a hole. Look at all of them before doing the glue trick.  Here is one:

See the dried glue at the bottom? It has to come out before the new assembly takes place. I use a small chisel to clean the sides and bottom.

I use a bigger one to treat the rungs before they go in. But first the clean out ceremony on all the holes.

There are a total of twenty eight holes in this chair. Don't believe me? Seven rungs - 14 ends, plus four leg holes and two back hoop holes in the seat, four back rungs with four holes in the hoop for them and four in the seat.

Not to mention four screw holes and two slots for wedges. A whole lotta holes!

The reason for the hardened glue at the bottom of the holes is simple. As the round pegs go in, they push a slug of glue in front of them that has nowhere to go, This hardened glue will prevent the next batch from moving out of the way of the rung, and might make the joint looser than it could be.

A quarter inch chisel takes care of the old glue.

Now about the new glue, and Mark's Method of promoting the best possible results.

First I treat the ends with my honkin' big chisel to make a series of thin wedge cuts at the ends of each peg that goes into a hole. See?

The reason for the little slots in the sides of the peg bits is to allow air pressure and glue to ooze back up and out of the hole if there is an excess that can't be accommodated at the bottom of the hole.

And the other thing I do is pay attention to where the glue goes. Glue works by sticking the sides of the hole to the sides of the rung, and the rung almost never gets to the bottom of the hole. So it is pointless, and counter productive to put glue on the bottom of the hole.

Some lesser people advise putting a ring of glue around the uppermost edge of the hole or around the leading bit of the rung and let the insertion process spread it to where it will do the most good.

Not me.

If I want the glue to be on the surfaces that are supposed to be together, I put it there. I use a stick to spread a thin coat of glue all around the insides of each hole, and I also put a thin film of glue on the corresponding surface of the rung that goes in. Some excess goes down the hole, and some oozes up around the rung. And I clean it up after the rung goes home.

In order to prevent a frenzy of glue spreading and the ticking clock, I do the glue ceremony step by step, first assembling the rungs to legs in a pattern that makes it easy to work, and still assemble the bottom bits in a calm manner.

Take a look.

See one leg with three rungs applied ready to glue. There is another leg with no rungs at all, another leg with two rungs.

You can't see the other leg but it also has rungs sticking in it.

The reason is simple.  All seven rungs will have one end already glued into place before I even start inserting legs into the seat.

This makes each leg insertion a simple process of applying glue to a few relevant ends and holes. Do this a few times, and put the whole thing together by joining the various sub assemblys.

Folks, it takes more than ten minutes to do a slop job of applying the glue to the right places and then sticking all those parts together before the glue loses its grip, and you begin to lose your grip too.

So do it my way.

It is so superior to a frenzy of eighteen holes to glue with four leg ends and fourteen rung ends with a total 'open time' for most glue of ten minutes or less.

Open time for glue is important. Each glue has an allowable time open to the air before it skins over and needs to be cleaned off because it will not stick right. It is not enough to apply more on top because the skin is still there.

There is another reason to be selective about which glue to use for putting tight fitting pegs into round holes.

Some glue has a very rapid 'grab' where it starts to stick almost right away after pressure is applied. This is not good if the glue grabs while the peg is half way in. You either break the grab (ruining the strength of the ultimate joint) or have a great deal of trouble pulling the danged thing back out to try again.

In doubt about which glue to use? Read the label. If it doesn't tell you? Don't buy or use it.

I like hide glue because it gives a decent amount of open and repositioning time, and is ultimately both stronger than most white glues (yes its true, despite being an ancient formula) and it is gently reversible using heat and moisture.

But it is not suitable for building boats, exterior use, or in damp steamy locations.

In my next blog we will get on to putting the top bits on and a few more secrets from your friendly chair doctor.

And remember that butcher block conversion to a desk blog a while back?

The whole thing is smooth and sensuous to caress despite its rough look.  Here is a snap its happy owner sent me of it in its new home.

Saturday, November 26, 2011

shrinkage cracks in the Seat

I sanded the seat after it came out of the clamps and at the back, it looked like this:

So it is time to do the wood filler trick. I do not buy retail wood filler, I make my own.

This time I used a combo of Titebond liquid hide glue and some sanding dust from the filter bag on my excellent Ridgid random orbital sander with variable speed.

Stir it together to form a thick paste and use a small spatula to force it into the cracks.  Here is what the filler kit looks like. I keep vials of dust from a variety of wood species and use various glues to make the paste, from Weldbond to hide glue to epoxies, depending on circumstances and what effect I am looking for. This time I want the filler to show as a dark line.

So here is the filler 

When sanded clean the cracks show dark.

Next trick is to show you how I sand the rungs.

Here is a picture of the setup.

Note: The lathe is unplugged since I am going to rotate it by hand. I have also disconnected the drive pully from the motor so I can turn the shaft easily.

You will note also that I have a Jacob's chuck in the lathe on a Morse taper. It allows me to grip small stuff for turning and other work without cutting a cross in the end for a standard lathe turning fitting.

The tail piece with its ball bearing pointy head keeps the rung on the level, and I merely run the sander along the rung on slow while turning the rung slowly by hand.

My sander is connected directly to my shop vac for efficient dust control.

Tune in soon for a discussion of how to deal with the way the legs fit under the warped seat and how to move the holes around to suit the new geometry.

You might be amazed by my cleverness. Or not.