The park benches in our church courtyard were in sad shape. Sad probably isn’t the best word. More like sobbing-your-eyes-out shape. The wood slats were crumbling or missing entirely and only the rusted bolts and layers of black paint were holding them together.
When my ever-loving wife, “Queenie” (not her real name), saw the benches she tipped her head back ever so slightly and pronounced, “We are not amused.” She let it be known that they should be tossed in the rubbish heap, which for park benches is the equivalent of “Off with their heads!”
But one of them had a nameplate reading, “In Memory of Elizabeth” and the deteriorating benches were threatening to take that memory with them.
Since the benches were sitting on an ipe (pronounced “ee-pay“) deck, I decided to rebuild them using ipe slats so they would look like they belonged there. Ipe is a Brazilian walnut hardwood. Very hard. Very dense. Very heavy. This makes it an excellent wood for outdoor furniture and it requires very little maintenance. It is so dense it doesn’t absorb much moisture and most sealers just sit on the surface because they can’t penetrate into the wood grain. A very, very thin layer of hardwood oil is the only thing they will take.
Since you can’t just walk in to your local Lowe’s or Home Depot to buy a few feet of ipe, I found an excellent source for it online at AdvantageLumber.com. They manufacture “sustainably harvested” exotic hardwood, which is important when using wood from Brazil (or anywhere). The salesman was helpful and knowledgeable. Highly recommended.
Most of the bench slats were 2″ wide with another three that were 1″ wide at the top and bottom. AdvantageLumber had 1 x 6 ipe deck boards on sale in 4′ lengths so I ripped them into a pair of 2″ slats and a single 1″ slat. The math worked out pretty well for the number I needed of each size. Ipe sawdust is a very fine yellow powder that looks like pine pollen and gets everywhere. I should have hooked up the Shop Vac for dust collection while I was using the table saw. I also should have worn gloves because unfinished ipe makes for hard, sharp slivers. Don’t ask me how I know.
Then I ran the new slats through the router to round over the sharp corners. (This time I remembered to hook up the vac and wear gloves.)
I chose type 316 stainless steel carriage bolts to attach the slats to the wrought iron bench sides because I like the look of the round caps and they will last forever. Every slat needed two holes drilled for the bolts so I set up a jig on the drill press to position each slat at the right distance from the end and centered width-wise.
I bought a new cobalt drill bit for this project because the web said ipe can dull ordinary bits.
There is some debate as to whether you should sand ipe because sanding will make the surface even harder and less able to absorb the protective oil finish. Since people were going to be sitting on these benches I decided it would be more important to sand them so as not to snag Grandma’s bloomers.
I set up a scaffold as my sanding station out in the carport so the wind (and a fan) could blow the dust away. The trick to sanding a long narrow board like a slat is to find a way to clamp it down so it won’t move. I screwed down a small piece of molding to butt up against the left end of the slat and then screwed down a short rounded off board on the right end of the slat. The screw was off center a little so that rotating the board would tighten or loosen against the slat. Both clamping boards were thinner than the ipe so that the sander could go all the way across the ends of the slats.
I used a belt sander with 100 grit sandpaper to take off the saw marks and any flaws followed by a pad sander with 120 grit sandpaper to finish it and smooth the corners of the long faces. I didn’t sand the ends of the slats because they needed to be coated with wax to prevent checking/splitting.
To apply the wax to the ends, I piled the slats tightly together and brushed it on the whole pile at once. The wax is supposed to be as thick as possible without running.
After the wax had dried the next day, I wiped off the sawdust from each slat with a cloth dampened with mineral spirits and hung it on a finishing nail driven into the edge of a plank on the top of the scaffold so that it would dry and stay clean.
Then I put on rubber gloves and brushed a little hardwood oil on a slat and wiped it down with my hand in a sock trying to get as much of the oil off as possible because any oil that didn’t penetrate the wood would eventually become sticky goo and we don’t want Grandma to sit in sticky goo. The sock picked up enough oil that I often didn’t need to brush any oil on the next slat and simply started wiping it down with the sock. Each slat was returned to its nail on the plank so it would dry.
The holes for the bolts in the wrought iron sides were not perfectly aligned as if they had been hand drilled as the bench was begin assembled. Some holes were a full 1/4″ closer to the edge than others. Since the holes in the new slats were all the same distance from the ends, many of the holes in the wood weren’t going to line up with the holes in the iron. To fix this problem I used a round file to “move” the hole in the iron to where it should be and then redrilled the holes in the iron with a larger bit to give the carriage bolts more wiggle room. It was tiring filing by hand so I replaced the blade in my jigsaw with the round file. Running the jigsaw at a fairly low speed made filing out the holes much easier.
The next challenge was literally (and I do mean literally) putting a square peg in a round hole. Carriage bolts have a square top under the big round dome that embeds in the wood to keep the bolt from turning when you tighten the nut on the other end. The square top will sink into the grain of softwoods like pine if you just hold the dome while you are tightening the nut. Ipe is not soft. It is very hard. (See above.) The square top won’t just bite in as you tighten the nut. I didn’t have a chisel or mortising jig small enough to make the little square hole. I did have a hammer and took the adage to heart, “If all you have is a hammer, everything looks like a nail.” Before assembling the bench, I hammered a carriage bolt into each (round) hole to form the square hole. This is risky because it is easy to split the wood, which happened a couple of times on the 1″ pieces. (If you have a suggestion on how to make a small square hole, please put it in the comment box below.)
With the enlarged holes in the iron and square holes in the surface of the ipe, bolting the slats to the iron sides was pretty straightforward. The slats had some variation in color so I alternated the dark, light, and medium ones to provide a more pleasing effect.
I wrapped a 1″ strap of aluminum around the back and bottom of the slats to distribute the weight when someone sits on the bench. I used an old strap as a template for making the new straps. Again the screw holes were not spaced correctly so I had to bend the slats a little to make them line up. In the future I won’t trust the old parts to be right and will instead measure and mark based on the new pieces.
Two metal braces run from the iron sides to a slat to keep the bench from racking side to side. The holes for the bolts in the sides were, wait for it …, round! So I had to file a square pocket for the carriage bolt head to fit in. The triangular file worked well because while two of the corners were making a side flat, the third corner rode against the opposite side and helped push the file down. I found that pointing the file at a slight angle toward the middle of the hole quickly cut the proper shape.
After bolting and screwing the metal braces, I flipped the bench right-side up and invited Queenie to place the royal buttocks on the ipe outdoor “throne.” Her Majesty was visibly pleased. Upon reflecting on the fact that the benches were to be returned to the churchyard, however, she decreed that I would just have to make her another one.
It is tough to please royalty.
7 thoughts on “Park bench resurrection”
Square holes 🙂
Gary, I’m planning on restoring the same bench you have in the photographs. I ordered the ipe from the same supplier as you did, and the stainless steal bolts.
However the question I have is what size bolts did you use?
I ordered 3/8″ x 1-1/14 stainless carriage bolts, but they’re too large to fit through the existing holes in the frame. Did you use a smaller bolt?
My fears are that drilling out the larger holes might weaken either the frame or the slats, but then the smaller bolt won’t be as strong.
Yes, 3/8″ sounds a little large. I used
316 Stainless Steel Square Neck Carriage Bolt, 5/16″-18 Thread, 1-1/4″ Long
The 5/16″ seemed to be the right size. I had to enlarge some of the holes in the metal frame because they were not aligned a consistent distance from the edge of the metal. They must have been hand drilled originally right through the wood slat, whereas I had used a jig on the drill press to make the holes exactly the same distance from each end of the slat.
So I would recommend using a smaller bolt but also don’t worry about enlarging the holes a little bit if you need to.
how to fit carriage bolts into hardwood
“And all the people of the kingdom rejoiced.” Brilliant and wonderful, Gary!
How many of these did you have to repair? It looks great!
I had to rebuild two benches. Glad you like them.