Monday, August 31, 2009

A Bit Of A Departure

I've got some non-wood-related stuff going on right now. Yesterday I was doing bricklaying for the first time in... years. Soon I'll be patching drywall and whatnot. Is anyone interested in blog entries on the non-wood stuff?


Wednesday, August 26, 2009

Sofa Table Completed

Okay, so after endless sanding, two bouts of staining, etc. I've got three coats of brushed-on polyurethane, scuff-sanded with stearated 400 grit (FEPA 600 grit) sandpaper between coats. The third coat turned out so well that I just left it as it was. I was planning on putting on four heavy coats, sanding it down, then putting on wipe-on poly for the final coat. Apparently my brushing skills aren't quite as woeful as I thought, because the third coat turned out great and I decided to go with it. So it's done. It wasn't as difficult as I thought it might be, but it certainly took a while waiting for the thing to dry or dust to settle before the next coat.
As it sits it still has some sanding-dust in the decorative grooving that I'll have to get out, but it's done.

Some things that I learned on this project:
- a raking light isn't a luxury - it's a necessity!
- the world of wood-finishing solvents is far more complicated than it needs to be.
- having a $40 sanding block doesn't make sanding fun, but it *does* make it more tolerable.
- it can take a long time for wax to settle out of shellac.
- brushing varnish (polyurethane) isn't as hard as I thought it would be.
- some finish fixes are dead easy. Others are a lot of work.
- having a separate finishing room would be really, really nice.

Oh, and if you don't remember how scratched and maimed it was when I started, here it is:

Good luck with your own finishing projects!

Monday, August 24, 2009

Poly for the Sofa Table

The sofa table top has been stained. Twice. Well, you see the first time I didn't sand it properly. I sanded it. Plenty. What I missed was a proper raking light. Now I know better. A raking light is all-important. If you don't have a good, strong light source to rake across the surface then you don't really know whether you've sanded enough. It looked great to me. I couldn't see any scratches - until I stained it, that is. Oy.
So I had to strip it and sand it all over again, and I stained it again. This time I didn't seal it... I wanted the stain darker, so I decided to take my chances with the potential blotching. As it is I got a very minor amount. I'm happy with it. The natural colour of the wood that this table is made out of varies somewhat. This makes for an uneven colour when you 'strike the stain' (wipe off the excess after wiping on plenty and letting it sit for ten minutes). When you rub the excess stain off you can rub a bit more and/or harder on the areas that had darker wood so as to even out the colour a bit. You can get close enough for jazz just by doing this on each coat.
Anyway, I put the last coat of stain on at about 7am this morning. The instructions on the can say that you can apply polyurethane after 8 hours. I waited 12 hours, but it wasn't really long enough... I was picking up stain with the brush. Not a lot, though. I think it will be fine. I laid on one heavy coat of poly with a brush (the raking light helps a lot with this procedure, as well!) and in the morning I'll see if I can add another coat. I'll probably put four coats on, scuff-sanding in between, then let it dry for a good week, then level the finish, then wipe on another couple of coats of wiping poly. I'm not good enough with a brush to be able to brush on a finish coat of poly, so my final coats are best wiped on. Safer. :) I'll let you know how it goes...

Monday, August 17, 2009

Refinishing the Sofa Table Top -- Seal and fill the pores

First I need to mix up my shellac. If you use shellac out of a can then you can ignore this. The reason I'm sealing the surface is because I've heard that mahogany, depending on the origin, can be blotchy to stain. The solution to that problem would be a commercial wood conditioner, or for we penny pinchers, a wash-coat of shellac.
Above we see a container of methyl hydrate, which is a very pure (but very poisonous, and probably carcinogenic) alcohol, flanked by two jars. One has my mixed shellac and the other is full of un-mixed shellac flakes. Shellac flakes, properly stored, will keep for years. Once mixed it will begin losing its ability to cure in about a year, the books say.
Shellac can be mixed in different strengths. For a wash-coat you want a one-pound-cut which means one pound of shellac dissolved in one gallon of alcohol. This equates to one ounce, by weight, of shellac in one cup of alcohol. I weighed an ounce of shellac, and added it to a cup of alcohol in a jam jar. Plastic or glass is fine to store shellac. Metal isn't. Every fifteen minutes or so for an hour I'd give the jar a swirl to help the flakes dissolve. You could shake the jar, but there's always that chance that you might seal the lid shut from the inside if you get shellac up that high in the jar, so I just swirl it. Then I let it sit over night to settle. This will allow any dirt, bits of bugs, and wax to settle out. In the morning I pour a bit of the clear stuff at the top into a bowl and wipe it on the prepared, previously-wiped-again-with-mineral-spirits-and-a-clean-rag sofa table top with a clean cloth. Job done.

An hour later the top is ready to have the pores filled. This I have never done. At all. I checked my books and got at it. I mixed up some water putty into a thin paste. Water putty is similar to shellac flakes in that in its dry form it lasts for ages. You mix it with water (surprise!) and the powder can be mixed as thick or thin as you want.

Once my putty was mixed up I wanted to darken it. The fastest way to darken something is using carbon-black, and the most accessible form of that, for me, is india ink. I added some to the putty, and that made it a dark gray, but I wanted something vaguely reddish-brownish so I added some burnt-sierra artists colour. For a water-based mixture like this you could use acrylic colour, but I have a weird water-mixable oil colour that has the benefit of being mixable in either oil or water, so I don't have to worry quite as much about putting the wrong colour somewhere. If I had been able to find dry pigments I would have gone that route instead.
Anyway, I mixed the colour in and applied the paste to the table top with a swirling motion to force the paste into the pores of the wood.

I waited about 15 minutes and then wiped as much of it off as I could. If I had been thinking I would have wiped the edges while it was still wet to make sure none of the putty was over-hanging. As it was it was quite irritating to remove the dried putty from the finished surfaces.
After wiping off the excess I allowed the table to dry over night, then sanded it by hand with 180 grit in the direction of the grain to remove the raised grain and putty residue.

Refinishing the Sofa Table Top -- Stripping the top

I have already oiled the majority of the sofa table, but I did not oil the top because I wanted to completely refinish the top. I don't really have much experience doing this, but that doesn't usually stop me from trying.
So I took the cabinet scraper to the top only to find that the top isn't level. Apparently the pieces were sanded separately then glued together, because the joints aren't level. The cabinet scraper couldn't get it all because it kept riding up on the higher pieces so the blade would stop cutting. If I kept going to cut down the higher piece I would have torn out the far edge. Having been stopped at this point with the cabinet scraper I switched to a card scraper to get the majority of the rest of the finish off. There were some spots that I just could get at, though, at least not without removing a lot of material. An example is shown below - at the joints there is finish left, and it's ugly. I wiped the wood with alcohol to make it more visible.
I asked for opinions on the Canadian Woodworking finishing forum and decided to just sand the bejeebers out of the joints to level them, then blend them in. It won't be really flat, but it will be closer than it was.
After more scraping, and sanding, I ended up with this:

Now I let it sit over night. I wanted all of the dust to settle before I started doing any finishing.
The next step will be the seal the surface and fill the pores before staining and clear-coating.

Friday, August 14, 2009

Oiling the Sofa Table

The only real difference between what I'm doing to this sofa table and my normal method of 'Finish Reviving' is that I'm adding colour to the oil mixture. The reason I'm adding the colour is because the table is covered with scratches. Light scratches would be fixed by a coat of normal 'reviver', but some of the scratches on this table are downright huge - bordering on being gouges. They need some colour. I've spent a couple of days playing with commercial solutions, like finishing pens and even wax sticks and nothing has worked very well, quite frankly. At least, nothing has worked better than the cheap solution that I'm going to outline below.

I start with mineral spirits to wipe the piece down with. As I will get into later, I should have spent more time wiping the piece down. Or at least, I should have paid more attention when I was wiping the piece down. If there are problems that show up when you wipe on the mineral spirits then deal with them now rather than later. After wiping down the piece with mineral spirits I add boiled linseed oil to the mineral spirits left in the container. I want a rich mixture (more oil than mineral spirits) because in this case I added a good, solid slurp of wood stain, and since the stain is thin it will replace some of the mineral spirits. As long as the stain is not water-based it will mix right in. I just grabbed the darkest stain that I had and dumped some in. I ended up with some dark finish reviver as seen below:
I then used a clean rag to generously apply the oil mixture to the table. I have a piece of hardboard protecting my bench from drips and whatnot, because I want to be able to slop this stuff on with gay abandon. Get it in all the nooks and crannies. I saved the left-over reviver in a jam jar because after it dries I'll be looking for spots on the table that didn't get dark enough.
I've already noticed an area that I should have spotted while I was wiping the piece down with mineral spirits - a spot of adhesive of some sort. If I had noticed it in time then I could have saved myself some grief. As it is I'll have to strip that spot, then remove the adhesive, then apply the oil again, and wipe it down again. Ah well. Here's the table as it stands right now. I didn't oil the top because I'm going to refinish the top completely - it's too badly damaged and needs to be scraped.
Here's the table with the oil mixture slopped on. I had it upside down for convenience, and I used a corner of the rag to push the oil mixture into the 'decorative grooving'. After the 10 or 15 minutes, I'll wipe off the excess, and...
Here it is. It's looking a LOT better. The vast majority of the problems that it had have been sufficiently camouflaged by the oil mixture. Some of the really big chips need a bit more colour, and I'll get to that in a future posting. Right now I have to wait for this thing to dry over night.
A hint I'd like to pass along is to also pay attention when you're wiping the extra oil off. It's not that hard to miss a spot, and you don't want that, because the oil will take forever to dry when it's that thick, and it will dry with a dimpled orange-peel finish. If you catch it after a day and try to wipe it off then it will be sticky and it will grab the cloth and things will be unpleasant. Use a rag damp with mineral spirits to sort the problem out, then you'll have to wait for it to dry again.

Oh, and don't leave rags wet with linseed oil piled up in a garbage can. Although it's quite rare it's possible for oily rags to spontaneously combust, and linseed oil is famous for that. Leave the rags spread out on the bench and they will dry over night. Once the rags are dry they can be safely thrown in a garbage can.

Different Ways to Scrape Flat Surfaces

There are different ways to scrape a flat surface. Above we see the three most common methods for furniture. Leftmost is a card scraper, which is simply a rectangle of sheet metal which, properly sharpened, will do a lovely job. Behind is a scraping plane, and to the right is a cabinet scraper.
Each method has its pros and cons. The most maneuverable and by far the cheapest is the card scraper. Since the card scraper is held in the hands you can hold it at whatever angle you like. You can push or pull it as you like. You can work on a tiny area of tear-out without affecting the area nearby, and you can work pretty far into a corner when you need to. These are all good things. The drawback to a card scraper is that it is by far the most physically demanding to use. Your thumbs get hot, and your hands get tired. It's miserable to do a large piece with a card scraper. Additionally, since it has no 'sole' it can't be relied on at all to level a piece or even keep an already-level piece level. It can dig into softer areas. You get a smooth finish, but not necessarily a flat one.
The cabinet scraper is more expensive. It's far less physically demanding to use, and it has a sole so it keeps the surface reasonably level. The main drawback is that you can't 'finesse' it much. The scraper blade is held at an angle set by the cast-in angle of the body. You can adjust the hook of the scraper blade to make the unit cut more or less aggressively, and you can add more or less pressure on the screw to adjust the aggressiveness, but you're still locked in to that angle.
The scraper plane has the longest sole, so it keep the surface the flattest. This also means that it is not very useful for working small areas of reversing grain. The scraper plane is the most expensive, but while it shares the ease of use of the cabinet scraper it also has a level of adjustability that the cabinet scraper can't even dream of - you can adjust the angle. This means that you can take a wide, thin shaving, or a narrow, thin shaving without re-tuning the blade. You can fine-tune the presentation of the blade to the wood and you are done - all that's left is to push it. No stress, no anguished thumbs. It's lovely.

Note that a scraper should take shavings as seen below. If all you are getting is dust then you need to sharpen your scraper... but that's a posting for another day.

Fixing a Dull Finish

This is by far the easiest repair to make to a finish. You have two general options, though it's best to do both.
The first option is a coat of wax. Regular paste wax can do wonders for a finish, and properly applied it will give the finish a small amount of additional protection. If you use a dark paste wax on dark furniture then it will help to hide small scratches and whatnot, as well.
The second option, and the one that I prefer as a first step, is to revive the finish by cleaning and oiling it. You can buy commercial "Finish Reviver" liquids, but essentially you can get that effect with mineral spirits and linseed oil.
Take this old drawer, seen below. I was given an old dresser by a lady I worked with. It's a beautiful old thing. Hand-cut dovetails on the drawers, and good, thick burl veneer on the solid faces. It's good, honest furniture. It also looks like it hasn't gotten any love for a long, long time. I've had it for over a year and I know I haven't given it any. Sure, it does a fine job of keeping my underwear off the floor, but it's dull and un-distinguished looking.
Now, look again at that drawer. That washed out look comes from exposure to UV rays (sunlight). A dead giveaway is that the finish is darker and more 'lively' where it's in the lee of the drawer pull... the light must have been coming from the right hand side for most of the dresser's life. This dark spot gives me my first inkling of what the drawer should look like.

I'm going to revive the finish on this one drawer face. First I take a bit of mineral spirits and pour it into a container. I rub the finish in an inconspicuous spot. Why? If the finish was french polish (shellac) then the mineral spirits would take the finish right off. That's not what I want! So I check to see if I can rub any brown off of the finish with straight mineral spirits. Nope. It's probably coated with a cellulose lacquer. Okay, so I wipe the drawer face down with mineral spirits and that helps to remove dirt and prepare the surface. Now I add boiled linseed oil to the bowl. I want at least 25% linseed oil, but 50% wouldn't be a problem. You could make yourself a container of 'reviver' with 25% linseed oil and 75% mineral spirits. I should do that, but I haven't bothered yet. Now I wipe the mixture onto the drawer front. I leave it pretty thick because I'm going to wipe off the excess after 10 minutes, and I'll give it a good buff with a clean cloth. After it dries over night it's good to go.
I put the drawer back into the dresser so you can play 'spot the drawer'. Can you guess which one has the 'revived finish'?
That drawer is looking pretty sweet. Now I have to do the rest of them, 'cause it looks funny.

I sincerely hope the lady who gave me this dresser doesn't read this blog, otherwise she'll be on my doorstep with a shotgun trying to get it back!

Since it's my dresser so it doesn't have to go back to some anxious relative, I'll give the oil a whole week to really dry, and then I'll wax the piece using a dark wax. It's a 'belt and suspenders' thing. The waxing can be done with the drawers in place (and still full of clothes) but you'd be best off emptying the drawers to do the oiling.

This whole job took about 15 minutes to do, and that included waiting 10 minutes for the oil to 'set' before I wiped it off. Doing the whole dresser would probably take 20 minutes. It would be best to stand the dresser on a cloth - if you drip oil on your floor you'll regret it, though it can be cleaned up easily (before it dries) with mineral spirits.
Don't oil the insides of drawers or furniture - it takes forever to dry and it will smell funny until it does.

I'll put another post up about waxing in particular.

Tuesday, August 11, 2009

Clamping for PVA glue

There was just a discussion on the Canadian Woodworking Forum that started to go off in tangents and one point made was that in R. Bruce Hoadley's book "Understanding Wood" he mentions that PVA glue actually requires a lot of pressure for proper adhesion. This struck me as a surprise. I often don't clamp my glued items at all, and he's referencing one or two hundred pounds per square inch for common North American woods. That just flies in the face of my experience, meagre though it may be, so I decided to do a test to make up my own mind about how necessary it is to apply tons of force. I built a simple test rig. The pieces are shown below:

The two pieces of 2x4 have 3/4" holes bored in them. These holes fit over the round bench dogs in my workbench so that I can use my vise to pull the rig apart to test the glue. The middle piece will be glued with one 2x4 piece on each side, so that both joints (clamped and un-clamped) are pulled at the same time. The first to fail is the weaker of the two. The larger 1" hole in the central board is to allow clamping it to the 2x4 on the 'pressure' side while not clamping the non-pressure side. This way I can do both of the joints at the same time so there is no worry about one joint having an extra day to cure before the test. The joints were glued within a few minutes of one another.
In the second picture below we see the clamped side of the rig being clamped by a bar clamp tightened up as far as I could get it (should be around 500lbs of pressure) and the other side has almost no pressure - it's being done in the manner of a 'rubbed joint', so the only clamping pressure is the weight of the workpiece above (and the clamp). Total weight - less than five pounds, so it's probably less than 1% of the clamping force.
I normally use a modified PVA glue - a yellow glue - so I bought a bottle of bog-standard white PVA glue for this test.

I'll let this sit over night and then test it in the morning.

Okay, it is now the morning (time flies, eh?) and I have done the test. The un-clamped joint was the one that failed, but it tore up the wood in the process, so it didn't go terribly easily. The results can be seen below: I'm going to do the test one last time after planing the failed joint again to clean it up. The reason is because I want to be sure that the unclamped joint was sitting right when it dried. When I did it the first time it had the weight of the clamp hanging on one side, possibly causing problems. Today the clamped joint won't need a clamp so the unclamped joint should be a lot happier. We'll see how it goes. It will be one more data point, anyway.

Okay, so I re-did the test, and once again it took a very hard pull to separate the pieces. So hard a pull that I am not really interested in trying to continue the experiments, as I fear for my bench. The non-clamped joint let go again, but again it went only with damage to both pieces so I am convinced that the un-clamped joint is more than strong enough. And remember - this was completely un-clamped. I am certain that a moderate clamping force is more than enough to make the joint far stronger than need be.

So, when next you clamp your glue joints put more effort into getting the surfaces flat rather than clamping them with tons of force.

Thursday, August 6, 2009

A Question for the Readers

My purpose for having this blog is to share knowledge, and help to maintain the knowledge base for hand-tool woodworking. There are many who do this better than I do, but I like to stick my oar in and see if we get anywhere.
The question, though, stems from this: As I looked at the table that I'm refinishing for the Finish Repair Project, I got to thinking of all of the wonderful tangents I could run off in. Scraping begets sharpening scrapers, and where a cabinet scraper works better than a hand scraper, or where a scraper plane trumps them both. I could talk about using lacquer sticks, shellac sticks, or wax sticks for fixing finishes - I could fix a few of the scratches and gouges before I strip the finish, just for the sake of educating myself and others.
Here's the real question: Do the tangents help, or do they cloud the issue? Should I focus on the task at hand and just document the project, and not worry about tangents unless people specifically ask for clarification?
Give me your opinions. Please!

Finish Repair Project

I've got this piece of furniture that came to me from a relative. It's got good bones, is structurally sound, and I like the lines of it. It's solid oak. The finish, however, is the pits.
I haven't quite decided what kind of table this is supposed to be. The size is right for a sofa table, but it's symmetrical front to back and doesn't sit flat against a wall or other surface, so while it probably would be okay for a sofa table, it wouldn't do for a side table. The openings in the top are to accept glass panels, which I have. I'm not even sure what style I'd call it. At first glance I thought the legs had a sort of 'Queen Anne' look, but the feet go the wrong way. Does anyone here know what style this would be considered?

Anyway, this project is a departure for me, so I'll probably be posting a lot about it. I'm hoping that I get a sense of accomplishment from restoring it, as it is 'frat-house grade' furniture, right now. Regardless of the outcome, I'm looking forward to getting some practice with scrapers and finishing.

The general approach will be to remove the tattered remnants of the original finish, steam out any dents, fill any remaining gouges, decide on a new finish, and apply it. I had considered repairing the existing finish, but decided against it. It's pretty rough, and some of the bare patches are pretty big, and in very, very visible locations.

Oh, and below are a couple of detail shots of some of the damage on this piece of furniture.

Sunday, August 2, 2009

Chopping to a line

There is a simple technique for chopping to a line with a chisel. This is important when dovetailing but comes up in other situations as well. Look at the picture below. I left quite a distance between the chisel edge and the line I'm going for (I should have left a bit less, truth be told).
Now look at the same chisel in the same location, except now I've given it two sharp raps straight down (the chisel is vertical).
The chisel is now touching the line. The bevel of the chisel forced it 'off course' and compressed the wood against the face of the chisel. Pull the chisel out and chop at an angle to remove some material as shown below:
When this wedge of material has been removed you will now be able to set the chisel in the cut again, but by angling the chisel 5 or 10 degrees over the waste material you will be able to hit it hard with the mallet to give a slight under-cut, but not corrupt the edge you have already chopped in its correct location.
When you do the same thing from the other side you'll have severed the piece and have two true edges on it. Lovely.

Cut-To-Line or Pare-To-Line?

I did an experiment. I have never been fond of the notion of paring a dovetail intentionally. Hey, we've all pared to a line after we screwed up the sawing of it, or when there are whiskers left over after chopping, but to saw cut short of the line with the expressed purpose of adding an extra step to pare to the line... It just never seemed sensible to me. However! Never let it be said that I was not Open Minded! An experiment was in order.
I dug a little example pin-board out of my scrap pile and found another piece of wood to cut tails in. The board in question was, sadly, not quite the same thickness as the pin board, and that came back to bite me just a wee bit, but more on that later.

So I marked out each end of this little bit of wood from the same pin board. One set on each end. I then marked them 'saw' and 'pare' and started sawing. The 'pare' end was sawed with about 1/16" left to pare away to get to the line. The 'saw' end was sawed right to the line. Here is the 'pare' end:

The 'saw' end went together as per normal. Unfortunately, since the pin board had come out of the scrap bin and it was slightly thinner material than the tail board, the pins are a bit short, but that's of no real importance here. What matters is the fit between the pins and tails. Here is the 'saw' end of the board:
It turned out well enough, tight enough that the glue-up would sort out its minor problems. It went together with firm hand pressure, and squeaked as it did so (you've got to like the squeak!).
The pared end was a shambles. Why? Despite my spending at least three times longer on it than the saw-to-line end, and using honest-to-gosh paring chisels sharp enough to do cataract surgery with, it was miserable to try to pare a flat plane in the right location. Why is that? That's because there's only a scribe mark on one side of the piece! How are you supposed to get the plane in the right place with only a depth and one side? it was misery. No doubt if you were a person who used various jigs and appliances to cut dovetails such that you didn't have to worry about maintaining the vertical plane, etc. you'd be alright, but I found the experience far from rosy.
Oh, here's a shot of the pared-end of the board, showing the gappy dovetails:

Bottom line? The saw, properly used, always gives you a nice, flat plane and is far more predictable than trying to pare free-hand after the fact. I'm going to stick with sawing to the line, particularly since it's hugely faster!