Introduction: Restore an Old Garden Bench
Nice looking garden benches, either new or restored, can be quite pricey at home & garden centers. Old garden benches in poor condition are easy to find at garage sales or online auctions such as ebay. Fixing or restoring an old garden bench is quite satisfying job that does not require any special skills.
This project took about me a weekend to complete, but if you were purchase pre-made wood slats this time would be greatly reduced.
This project breaks down into a few key steps that can be done in nearly any order.
- Measure up and choose your colours and materials.
- Clean up cast iron chair ends
- Cut wood to size
- Finishing (staining, painting, varnishing etc)
Step 1: Overview and Supplies Needed
- Chair ends
- About 8 hardwood slats about 25x50 mm or 1"x2" see step 3 for more details.
- Paint or other protective barrier for the metal. I used hammerite but rustoleum would also be fine.
- Paint brushes and rags
- Protective finish for your wood, I used teak oil but timber deck treatments or an polyurethanes would be fine.
- Screws, round head bolts, nuts and washers. I used 14 zinc plated 50mm M8 bolts (about 1/4" thick and 2" long) 15mm zinc plated phillips head screws
I also used some PVA glue for on some lap joints, but this is optional
Please also check out other authors work who done a similar project.
Step 2: Tools Required
A minimum tool kit would like:
- A tape measure.
- A study brush for cleaning up the metal.
- A handsaw, drill and drill bits for the wood.
- 4 or more clamps
- An adjustable wrench/spanner and a screw driver for assembly.
- safety gloves and glasses.
Nice to have tools
- An angle grinder or drill with a wire brush attachment. Using a drill attachment can be a little awkward.
- If you are using rough sawn timber like I did a circular saw with a fence or a table saw will be required. As will hand planes or a planner.
- I used a chisel for making lap joints on the back, but lap joints are optional.
- A router for insetting the back piece, also optional.
Step 3: Measure Up and Choose Your Materials and Colours
On the old chair ends count how planks and bolts you will need and measure the thickness of the channel in which the end of wood sits. It pays to measure the thickness in a few couple of places, better to be to thick and have to shave a little here and there than too thin and have the thing break. In my chair I measured 25mm or 1 inch, but it was clear some corners of the slats edges would trimming.
Measure the gap between the centre of two consective bolt holes, these holes wont be evenly spaced so it pays to do this in a few places. You'll need planks with a width about 75% of the shortest distance between consecutive holes. This width should still be at least twice the thickness of each plank I noticed most pre-cut garden chair planks for sale on ebay are 25x50mm (1" x 2") so go with this if you're still unsure, I went a little wider, 60mm, which is fairly close to 2.5".
Measure the length of the metal back piece and count how many screw tabs there are. The final length of the timber will be approximately the length of the back piece plus plus twice the width of the planks, so you'll want some timber slightly longer than this.
Choose a timber that is suited for outdoor use, I found some white oak at a timber merchant, other choices good choices would be cedar, sapele, iroko or mahogany. Benches made with softer wood such as treated pine require supporting middle structure.
Choose a finish that you are going to be happy with. Some metal paints can be forgiving on occasional rust spots which can save you a lot of time. Some woods will grey over time if you don't want this look for a marine finish with UV protection. The standard colours of benches are black ends with natural timber slats. However staining the timber black to match the ends would look quite striking. After experimenting with some stains and finishes on some off-cuts, I chose white and a copper colour for the metal and a teak oil finish on the wood.
Step 4: Clean Up and Paint the Metal
Using your firm brush and soapy water clean off all the dirt and grime. Many metal paints can tolerate a light surface rust, but it is important to try and remove big flaky pieces of rust. You can see I used a sanding disc on an angle grinder but I later shifted to a wire brush to get into all the crevices. Once clean you can paint the metal, two thin coats is often better than one thick coat. Personally I would delay painting until after cutting the wood to to size so you don't get wet paint on the wood, but this comes down to your personal timing.
Step 5: Cut a Frame for the Back Piece
After getting your lumber to the right width its important to make the frame around the back metal piece before proceeding any further. My back piece had a slight taper so the length of frame wasn't easy to establish.
Using a saw and chisel cut the optional lap joints on one side of the back piece. The advantage of lap joints is that the securing bolts goes through all pieces of wood. If you don't know how to make a lap joint see step 4 in this instructable https://www.instructables.com/id/Some-Basic-Woodwor...
Holding the lap joints in place with clamps push the metal back piece tightly against the frame measure and cut the shorter piece to size then cut laps only on the shorter piece. Mark the depth of the rim one onto a scrap or one of of the laps and use this depth to establish and the mark the position of the inside edge of the frame. Now the remaining lap joints can be cut and the frame completed.
The thickness of the back piece was thinner than the wood I was using so I measured the difference in height and cut away an inset grove with a router, taking away a little at a time. I then glued up the lap joints holding everything place with clamps.
Pre-drill screw holes so the wood didn't split before attaching the screws.
Measure the back piece and frame and the cut slats to the same length. I then rounded over the edges with a hand plane.
Step 6: Dry Fit Assembly, Finish, Then Reassemble
Place the back piece and frame into one of the chair mark out and drill the hole for the bolts on one side then the other. This may be easier with the help of a friend. I found I needed to chisel a corners few spots to get a good fit.
The nature of these garden benches is that the holes are not exactly in the same place on each side, so its best to assemble in-situ going by eye rather than precision measurements. With the bench part assembled place one of the wood slats into position, hold down the slat with clamps and check that the legs are square and parallel. Mark and drill a hole on one side, secure that end with a bolt and washer then repeat for the other side. Repeat these steps for each consecutive slat using spare bolts to achieve a parallel spacing.
Number each slat on the underside to remember their order, take the whole thing apart and treat the wood with teak oil or your alternative. I apply teak by dipping a rag in the oil and wiping on a thin coat. The disadvantage of teak or tung oil is that it needs to be reapplied every 6 months, but I don't mind this at all. More permanent finished like polyurethane need far less maintenance but may require complete resanding when refinishing.
Reassemble your bench and voila, you are done. Personally I didn't like the colour of the zinc plated bolts so I painted them with copper paint.