Saturday, September 22, 2012

Covered Bowl Turning

The first tool I ever really remember being taught how to use is the  lathe.  I must have been about 5 years old and yet I can remember standing on a box in front this huge machine with a gouge in my hand that felt like it was half my height.  One off the best parts of this memory was have dad standing behind me guiding every move I made.  The lathe in our family was part of a rite of passage and for me remains one of the most enjoyable tools in the shop.

With all the turning projects I've done, or seen done by dad, I don't recall doing a covered bowl.  So I thought I'd give it a try.  Andrew had a blank leftover from his candle project that was a bit thicker than the others.  It has a knot running through it and was hard to tell just how deep it ran, but I thought I'd using anyway.         


So the process is pretty simple and straightforward.  Mount the face place on the blank.  Rough turn the diameter and since I've been using the turning chuck turn the socket for it.  Then flip it over onto the chuck and it's creativity time.  At this point I began turning the lid.  I then took it off the lathe and chip carved in a cross.  Back to the lathe and finished the lid.  Then using a parting tool I cut down a step on the back of the lid.  I sanded and finished the lid at this point because once I parted it away from the rest of the body I wouldn't be able to turn it anymore.  Then using a parting tool I separated the lid and bowl.  Now all I had to do was turn a bowl.  The only thing I needed to do was be sure the rim was just big enough for the lid.

As I was finishing the bottom of the bowl the knot I was afraid of showed up.  So I went ahead and finished the turning.  I remember a video from the wood whisperer site that talked about filling and stabilizing a knot with epoxy.  Here is the link if you want to take a look:
                                                                                                                                                                                                                                           113 - Fixing a Knot March 14, 2010 A clever way to stabilize a knot so that it looks natural. →                                                                        

I haven't filled the knot yet but plan on it.  In any case here is the finished product.

Friday, September 14, 2012

Yeah I Could Make That or Diane's Work Table

As a couple goes through life together you get to know each other pretty well.  One of my many idiosyncrasies that Diane has had to deal with as we have gone through life together is listening to me say, as we pass by an piece of furniture, "yeah, I could make that".  Of course without a shop I never did.  Years passed and her responses have gone from a jubilant, "really that would be wonderful" to an affirming but knowing smile and nod of the head.

Enter the era of the shop and a new year for her at work with a few changes to her work area.  She asks if I could make an inexpensive work table that would fit into some fairly specific dimensions.   My response was quick and enthusiastic, " Yeah! I could make that"!

The first trip to the home center was to look at materials and get an idea how just how much would it cost.  I was thinking of using poplar, a good choice for painted or unseen construction.  By the time I would have had enough to glue up for a top and build the legs I was over fifty dollars, which does not fall into the inexpensive category.  I went home a bit dejected.  A few days later we were passing the other big box home center store and we stopped in.  As we were walking toward the lumber section we passed a display with cut MDF (Medium Density Fiberboard) that was just over the dimensions needed for the top.  Best of all it was only a bit over six dollars.  Down grade the base from poplar to common clear pine and the material price was cut in half.  Needless to say my spirit picked up a bit.

The pine they had was only 3/4 inch, which is too thin for the legs I wanted to build so I figured I'd just clean it up a bit and glue two pieces together.  So I brought the 3/4x3x8 (that 3/4 inches thick, 3 inches wide and 8 feet long) into the shop.  Spinning 8 foot boards around in a small space can be a real trick and that's all I'll say about that.  Anyway, without moving a lot of things around I couldn't get them on the table saw so I pulled out the old trusty hand saw.  Add an inch or two to the finish length, mark and with a few strokes of the saw I had four, almost equal, lengths for the legs.  Using standard yellow wood glue I squeezed out a zig zag pattern and spread it out with my finger.  I always keep a roll of paper towels in the shop which made cleaning the glue off my finger pretty easy.  I didn't have enough parallel clamps to clamp each leg by themselves so I just stacked two together and clamped them in sets.

So after the leg blanks had dried the next step to was figure out what shape I wanted.  This was a simple table so I wanted a simple leg shape, a taper along the width.  The outside of the leg would run straight and the taper would run along the inside of the width of the table.  To do this I pulled out a tapering jig I had made some time earlier for another project.

You can buy these jigs, and I'm sure they're really nice, but for one poplar board, or something else, a hinge, a lid stay and a few screws you can make one for pretty cheep.  You can see in the picture that the work piece is held at an angle to the fence.  As the piece is passed through the saw the jig moves along with the work held at an angle.  The results in a taper being cut rather than a straight cut.  Kinda of cool.  (Maybe if you want me to I'll write a blog on this, let me know.)

I really wanted this table to be strong.  Diane didn't want a stringer between the legs, wanting an open area below the table for boxes and such.  So I decided to use dovetails to hold the apron and legs together.  This is a pretty easy cut using a router table and make a real strong joint.  The best tip I can give you is that once you set the depth of the cutter DON'T CHANGE IT UNTIL ALL CUTS HAVE BEEN MADE.  That's on both the pins and the tails.

Use setup pieces to get the tail position right where you want it.  Start by placing the fence with rulers, taking a cut on the setup piece and measuring to see if you got it where you want it. Then measure from the trailing edge of the bit back to the full depth of the tail and placing a mark on the fence.  Then start your cut, advancing the work piece up to the line you drew and stop.  Don't forget to pull your piece back out the same way it went in, turning off the router is also a good idea.  Since I was using pine this cut was pretty easy.  One of the tricks with routers is to  creep up on your full depth of cut.  But with a dovetail you can't do this.  So as you are making your cut just go easy, let the machine do the cutting.  Also be sure you are minding safety protocols, the work area is clear, use push blocks, your safety glasses are on, hearing protection is in and don't stand on the side of the table where if there is a kickback the work will fly into your gut.

Cutting the pins is done in two passes, one each side of the board. As the apron boards are only three inches wide making a good and safe cut is almost impossible without a way to hold it.  So I made this quick jig out of a couple pieces of scraps.  The work piece is clamped to the post and allows controlled, safe, machining.

With the dove tails cut I cut a grove, known as a dado, 3/8 of inch from the upper edge of the apron.  This was to accept a L shaped piece to hold the top and base together.  These were made by cutting a rabbit designed to fit into the ditto on a long enough board to go through the table saw then cut them to about one inch wide.  At this point it was time to bring out the sanding block.  Yeah I could have done it with my power sander but this was pine and sands up really easy because it is so soft.  Sanding at this stage, that is before it is assembled, makes it a lot easier.  Then dry fit the base together and prep the clamps.  By preparing the clamps I mean determining a clamping strategy and setting them so that with a couple of turns the clamp is engaged.  Once you have the clamps in place don't trust that it is square.  With this piece the simplest way is to measure the diagonals.  If they are equal you should be square.  In my case I forgot to do this.  The results were that the base is slightly out of square, but fortunately not real noticeable.

On to the top.  As I said before I was making the top out of MDF.  To be honest I never really worked with MDF before.  From what I understood it takes paint very well on its surface but because the edges are more porous they can look dry compared to the surface.  A trick I found was to seal them with drywall compound, which is what I did.  This compound has an indicator in it, which is why it looks pink.  As it dries the pink turns white.  When it is completely dry and ready to sand it will be completely white.  Another mistake I made was to rough up the surface with a 200 grit sandpaper, a tip I read on line.  It didn't work out as I hoped, it left the surface much rougher that I thought it would after I painted it.  I put 2 coats of blue spray paint on it then a coat of clear.  It didn't turn out too bad and the paint took the edges pretty well.

Once the base came out of the clamps I touched up and glue drips by sanding them out.  I then applied three coats of polyurethane.   I like using a water based poly because it has much less fumes than a mineral based poly.  I did read that if I did use poly on the MDF not use the water based because it lifts up the surface, kind of like putting water on cardboard, and it just can't be sanded out.  But as I painted the top that doesn't much matter.

Finally, using the clips I made earlier I attached the base and top together.  I really liked the way they worked.  The technique would also would work well with a natural wood top.  Remember wood moves with moisture.  As the clips are not glued to the apron I'm thinking that as the top moves the clips should slide in the dado, keeping things from splitting.  This shouldn't be as much of a problem with MDF.

So this has been a fun project.  I know that every time I would say I could make that I was, at least in part, motivated by the desire to be able to give Diane something I thought she wanted.  It was a great pleasure to do that this time and actually complete it.  It now sets behind her in the office, holding books, or boxes, or stacks of mailings or what ever.  And can say yes I can.