Tuesday, December 31, 2013

Daniel Pratt Jr. Clock Restoration - Part 1 of 3

Part 1 will cover the restoration of the veneer and case components, part 2 will show the movement cleaning and repairs, and part 3 will show the finished clock.

I began the project by gathering-up all the parts of the clock that had been scattered around the house. The clock case was upstairs along with a grab-bag of parts (pendulum, hands, pins and wood chips, etc), while the door and pendulum rod were in the basement.

I also brought together all my repair materials:

- Mahogany veneer packs
- Cherry repair blanks (for wooden wheel repairs)
- Thick-cut "mahogany" door veneer*
- Veneer saw
- Hide glue
- Carpenter's glue
- Pine scraps
- Clamps (you need lots of these!)
- Painter's tape
- Acrylic paints
- Dye stain
- Oil stain
- Artist's brushes
- Craft knife
- Chisel(s)

As well as other common sundries like a pencil, ruler, toothpicks, cardboard (for mixing paints and making patterns), etc.

* I use a mix of "incorrect" woods in my restorations simply because they were easy for me to find (or free). Several years ago I needed a 1 1/2" thick slab of mahogany (about 12x12) to cut thick door veneer for wooden works clocks. I couldn't find any locally, but I got a good deal on a chunk of Sapele instead, which I then cut into dozens of packs of 45 degree and 90 degree door veneer (1/16" thick). Those packs can be seen wrapped in green tape below. Sapele is a tropical wood that is very similar to mahogany. It has similar grain, and colour, and for most repair jobs, it's not very noticeable. I also have a large stock of scrap pieces of Spanish cedar, which is also very similar to mahogany, but it's much softer and paler than mahogany. I avoid using it whenever possible, but my stock of mahogany scraps is limited. Select pieces of Spanish cedar were used on the longcase clock (the small cove mouldings under the swan neck moulding).

I was able to obtain several "bundle packs" of mahogany crotch pieces. You can see a whole pile of those in the photo below. The best source I've found for veneers is on eBay. I believe these packs were about 10-15$ for roughly 100 sq/ft mixed bundles (plus shipping). These are wonderful for repairs, since it can be difficult to match crotch mahogany veneers.

I have also purchased large batches of "cathedral" crotch cuts, which you can see below above the tape measure. The piece shown is actually the top half of a sheet that broke in the centre. Long pieces are useful to have for side repairs or back boards.

The first two pieces to be repaired were the door, and the dial retaining strip. These were repaired using hot hide glue, clamped overnight.

The entire centre divider in the door was loose, as well as the veneer on the face, so all the veneer was removed, the old glue scraped off, and the bar was re-installed (also with hide glue).

While parts were in the clamps, I started to work on the splat and the missing (left) side return.

I picked-out a piece of antique pine (from my stash of old wood), and I found a suitable sheet of crotch mahogany.

I would have preferred an off-centre crotch cut like this Daniel Pratt clock below, but none of my pieces were wide enough.

To make the pattern for any missing top splat (which I've had to do often), I always create an exact copy from an existing clock by the same maker. To do this, all you need is a head-on photo of a complete clock, photo-editing software (such as Photoshop or GIMP), and the width between the chimneys.

For the missing splat on this clock, the distance between both chimneys was exactly 12". I went ahead and selected tops from 3 similar Pratt clocks, and cropped the images square with the inside edges of the chimneys, then resized the photo to 12" wide. This gave me 3 splat options, and I picked the one I preferred (splat #3):

Since my printer won't print up to 12", and I usually prefer to flip a pattern over to mirror both sides, I cropped-out 1/3 of the photo, and printed it. You can see my printed pattern glued to cardboard in the photo of the splat pieces above. Note that the printed pattern at 12" DOES NOT INCLUDE the extra 1/4" for the mortises into both chimneys. This extra 1/4" must be added on each side or the splat will be too short (the extra 1/4" shows up on the pattern as just a white stripe).

The splat veneer was glued with hide glue and clamped solidly between 2 boards overnight (or longer if possible).

Back to the door.

With the centre bar now firmly reglued, I made the repair to the bottom hinge corner. The clean break between the wood (diagonal crack) was repaired with carpenter's glue, while the slotted (slip mortise) corner joint was glued with hot hide glue.


To reattach the centre strip of veneer, I laid out a straight line in painter's tape on the glass to use as a reference (since the veneer overhangs both sides and it's hard to judge if you're gluing it crooked).

The veneer on the door centre bar had been previously glued in the wrong spot (if you check the before photos). For some reason, all the veneer edges in the lower door had a nearly black paint or stain along the interior edges. This meant that the veneer needed to be installed 180 degrees from where it had been previously (and poorly) been installed by the last restorer. The grain on this veneer section was also unusual because it started on the left with a slight lean to the left, and gradually leaned far over to the right nearly to 45 degrees. The veneer on this piece should have been just vertical, but I assume that they just used whatever veneer they had.

90% of the original veneer was reattached to repair the centre bar, with just one missing piece on the far right.

The rest of the veneer repairs on the door were simple patches. Since my veneer (1/16" thick) was a bit too thick, all the patches needed to be block-sanded flat.

Side note: Block sanding is when you use a stiff wooden block faced with sand paper to sand down a surface perfectly smooth (and flat) as opposed to hand-sanding or sanding with a pad that has a soft or sponge facing.

One other repair to the door was to correct a previous repair (in the centre of the right side). In the before photo the veneer here appears to be cracked and buckled. This was caused by a poorly aligned glue repair to two sections of veneer that had been reattached. These two sections were carefully removed, the glue was scraped off the door frame and the back of the veneer, and they were re-installed. The blue arrows point to two triangular pieces of veneer that were still attached with the original glue joint. The surface of the veneer was sanded and puttied to help blend the repairs.



A simple patch on the upper left. This close-up gives a good example of the mahogany vs. sapele. It's very hard to tell the difference, though I'd still prefer mahogany when I can get my hands on some.

I'm not sure if the veneer around the keyhole is an old repair or not (because of the uneven inside edge), but it looked original and I left it alone. The photo shows the shadows of the escutcheon pins.

The clock would have had one of these:

More veneer patches to the case. Some sections needed thick veneer, while others needed thin (regular modern) veneer.

Splat and side return in the clamps, along with their corresponding patterns. Luckily I had an existing side return for my pattern, since photos of side returns can sometimes be difficult to find. In a worst case scenario, one could be traced freehand to a close match on other clocks. Generally the side returns follow only a few common patterns.

Here you can now see the case with all the veneer repairs installed, sanded, and puttied (where needed). There are 11 new patches. You will note that on the column "blocks" (top right and bottom left), and full-length strip of veneer was used for chip repairs, and the entire surface was sanded (including the original finish on the non-patched area). I find that this method creates the best overall repair, since it's difficult to repair only a small section of a piece, while also trying to blend it in.

In the past few years, I've also developed a preference to removing and replacing more original veneer than is sometimes needed in order to accomplish a better looking repair. This can be seen in the full strip removed from the top right column block to repair a small chip. The other option would have required a diagonally cut, or oddly shaped patch, and I think it would have been a lot more visible.

Moving on, here is the newly cut splat (not yet installed).

Two other case pieces still needed repairs: the chimney blocks.

I have to assume that the clock was broken by the splat, since both chimney blocks had breaks to the front mortises. The left one needed a simple rectangular block. Office supplies sometimes make very convenient clamps!

The right hand block is another controversial repair. To properly fix this block involved removing the face veneer. Though the veneer was largely intact (see before photo), I chose to remove it. The other problem with keeping the original veneer was also in the fact that the veneer on these two chimney blocks runs horizontally, rather than vertically. The repair patch would have been cutting across the grain, and it would have looked bad.


Veneer removed (and saved for future repairs), and mortise repaired.

A new sheet of veneer was carefully chosen (for grain pattern, colour, and direction), and glued. The chimney cap was also nailed and reglued (hide glue).

Here you can see the repaired left chimney top, with its new side return. I had not previously mentioned this, but the face veneer on this block was also reglued (you can see the patched crack on the upper portion. The side veneer had a hole from added nails (removed), and a chip. Both were filled with wood filler.

Repaired right chimney top after repairs and new veneer.

It's at this point that I'll just quickly mention a quirk that I noticed on this clock as I was doing repairs. For whatever reason (laziness or cheapness) the left chimney block is about 3/4" thick, while the right hand one is closet to 1 1/8". The 1/4" difference in depth is quite noticeable if you know to look for it. This goof also resulted in my pattern for the left side return being a bit too short.

Finally, here is the case with all the repairs done, and the top elements re-installed with hot hide glue.

This was after the first application of a light walnut stain:

Then after a second application of a darker stain to the lighter (newer) patches. Additionally, any areas that would not take stain adequately, or that needed additional blending, some paints were used, and carefully blended (read: professional finger painting). The paints that I normally use are acrylics in browns, reds, and black.

The last steps involved in the case restoration were to apply a few layers of amber shellac, followed by ample drying time, and a buffing with #0000 steel wool lubricated with dark paste wax.

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