Restoration Project
Andrew Atwood
 
Sorting Out the Upholstery, Carpeting & Steering Wheel
Part 11 of an ongoing series
 
We’re on the home stretch now. Since all my interior pieces and wood trim are refinished, it’s time to start the reassembly process. However, before going into those details, I needed to address the last part of the restoration process – the carpet, seats and upholstery. This is where I see a lot of failed attempts and horrible jobs that are sometimes worse to look at than the original upholstery. There is something to be said about an original interior with some patina on it. On the other hand, my interior was completely destroyed and had rats living in the seats;  trust me, this is not the good kind of patina.

Seat upholstery

When deciding what to do with your upholstery, your desired goal once again must be considered: Is the car to be show quality or an everyday driver?
Let’s start with the most common problem. The original padding was made from horsehair or some other fiber and rubberized glue that over time slowly dried out and deteriorated into piles of debris under the seats. Eventually, there’s no padding left and you’re basically sitting on  metal springs.

As long as the leather upholstery is in reasonable condition, the pads can be replaced with new ones, if available, or rebuilt; leather skins can be repaired and professionally redyed in the original color. When done correctly, the result can look very nice and feel almost like new.

However, if your seats look like mine did, then a completely different approach is needed: No amount of patching or dyeing would bring mine back to life – and that’s obvious in my pictures. As I removed the remains of the tattered and rat-eaten leather, I found the padding was essentially nonexistent. This meant I was going to have to completely rebuild my seats.

I could have simply given the seats to an upholsterer to rebuild, but that can be expensive. So with advice from an experienced friend, I decided to tackle the job myself. Fortunately, I was able to find the needed horsehair pads from an aftermarket source, though they often have to be made from scratch. Purchasing the pads for the front seat meant they would have the original contours and feel.

To start, I stripped all remaining remnants from the metal framework. Then I formed a flexible but solid surface over the springs on which to mount the new pads by using heavy plastic screen material, attaching it with upholstery hog rings using hog-ring pliers; it was firm enough so I could glue the original-style horsehair padding to it, and then cover the seats. This may not be how an upholsterer does it, but it worked nicely for me.

When it came to the leather, I had several options. First, I could use one of the numerous companies that make replica seat skins to be installed by the purchaser, or I could take the seats to a professional upholsterer locally and have the leather covering made, with the risk that the techniques used might not match those used on the original seats. I’ve had good results from World Upholstery & Trim in Santa Monica, California, and the company was able to supply me with leather kits in the original color with period-correct pleat pattern and stitching. The only task was to carefully and patiently fit the kits over the refurbished and repadded seats.

Carpeting

The interior carpeting was also all rat-eaten and rotten, but was the easiest part of the entire restoration project. Seriously, it was a genuine pleasure replacing it. This is definitely something almost anyone can tackle with just basic tools and some common sense. World Upholstery supplied me with the correct looped-pile wool carpet with period-correct color and  matching edging.

Installing carpet in these older Mercedes vehicles is very simple; builders didn’t fit the flooring from a large swath of carpet like U.S. manufacturers. Instead, they used small sections so that if one area were later to be damaged or soiled beyond repair, it could be replaced individually without having to replace the entire unit.

After I removed the seats and door-entrance moldings, I could pull up the old carpet and then clean and prep the floor for new carpet.
When installing the carpet, a good industrial-grade, interior-trim adhesive needs to be used so the carpet doesn’t come loose in hot weather or when vacuumed. I usually start with the sides and work toward the center. Be sure to test fit every piece first before applying glue or you’ll wind up destroying the carpet when trying to pull it back up to trim or get glue all over the carpet, which is next to impossible to clean with loop-pile carpet.

Be careful and take your time to get good results. As you can see from the photographs, there are a lot of uncarpeted areas, which is normal for cars from this era; if you’re going for an original look, keep that in mind if you decide to have a local upholstery shop make and install customized carpeting for your car.

Door cards

The last upholstered items were the door panels or, “door cards” as they are called in Europe. Mine looked as if they had been stacked in a Pringles potato chip can and then steamed; they were so warped and disfigured, I had to start from scratch to replace them.

I used a type of heavy interior board that is readily available through any upholstery supply store. I cut pieces to fit the doors, covered them with a very thin layer of foam and then glued the new leather trim over the foam. These are fairly easy to do; the hard part was rebuilding the map pockets and installing new elastic to keep them closed. Of course, I could have simply ordered a new set of finished door cards from a supplier.

Then it was a matter of reinstalling all my freshly refinished chrome and wood trim pieces: There are five pieces of wood on each door and anywhere from eight to 10 individual pieces of chrome trim per door on these old 300SEs.

Steering wheel

Now for the last interior piece – often overlooked – the steering wheel. Like many older cars with plastic rims that have sat in the Arizona desert sun, mine had many cracks, some up to a quarter of an inch in size. The repair technique is straightforward, but it does require a lot of patience and perseverance.

To fill cracks and chips, I used a panel-bonding two-part epoxy compound, such as made by 3M. Before applying the epoxy, it’s critical that all grease and oil be cleaned off the steering wheel or the cracks will quickly reappear; be diligent. Be sure to use panel-bonding epoxy; other types of epoxy won’t work as well.

Then it’s just a matter of filling the cracks with the compound and gently and slowly sanding the epoxy down to the original level of the steering wheel. I used a 600-grit max to start with and ended up finishing with 800-grit, which is perfect for painting prep.

To cover the fills and get a flawless finish, I primed the steering wheel with a good filler primer before painting and then sanded again with 800-grit paper. I find the filler primer fills all those stubborn tiny little hairline cracks found all over the wheel. With the wheel perfectly smooth, it was at last ready for painting.

To give it that perfect factory look, I opted  to use a professional painter with a dustless spray booth and baking oven. I could have saved money by using good-quality, high-heat engine enamel from a rattle can and baking it in the sun, but, after all my preparation, if the paint ran or bugs had landed on the freshly painted steering wheel, I would not have been happy.

While the steering wheel was out for painting, I recovered the horn pad using a marine-grade vinyl: It’s more flexible and doesn’t shrink in the heat. When the steering wheel came back from the paint shop, I was gratified to see all my hard work had paid off in a flawless finish. With the horn ring reattached, the W112’s steering wheel looks fresh from the factory. 

What’s next?

With the upholstery, carpeting and steering wheel restoration now successfully finished to my satisfaction, all that is left on the project list is final assembly, a thorough mechanical inspection and the test drives before the car will be ready for its formal debut. So until next time: Be careful, be smart and most of all be thorough.

Regular Star contributor Andrew Atwood  is the owner of Atwood European Repair and Service (www.atwoodeuropean.com) located in Phoenix, Arizona.
 


62 TOP: The rat-infested husks of my old seat covers.



Rebuilding the rear bench seat in my W112.




Comparison shot of new front seats with completely decayed original.The stripped and cleaned metal frame. Heavy plastic screen material substrate below the foam, attached with hog rings. The first layer of foam.
The finished seat covered in red leather. Aftermarket front lower seat pad and worn out original horsehair pad.



 Installing the period-correct loop-pile wool carpet with red piped edges and seams. First test fit of the rear bench on new carpeting.
 


Restored and unrestored steering wheels show the factory-like results you can get by spending the time to properly fill, sand and prepare an old steering wheel for painting.



I redid the door cards with heavy poster board, foam and leather – the refinished chrome hardware and wood trim now dazzle.
 


Detail of a decayed and cracked old steering wheel.



I first cleaned and degreased the wheel, filled cracks with a two-part epoxy compound, and then sanded  progressively, ending with filler primer and 800-grit paper to fill hairline cracks.



Black Beauty: the results were worth it.