Case Study | Leather Car Interior Restoration

Introduction

One of my favourite modern classic cars the BMW E30 convertible; 1988 325i M-sport. This is a very nice example but unfortunately the interior was letting the rest of the car down. It was my honour to transform this interior back to its former glory so that the owner, a repeat customer, can once again cruise around proudly and in style with the top down.
This project took a few weeks, and I had to utilise many of the various skills, techniques, and processes I use to carry out the repairs and refinishing.

BMW E30 Interior Restoration

Minor Leather Repairs

A well used 32yr old leather interior is going to have numerous knocks, bumps, and scrapes. The aim with this project was not to try to make everything perfect but to deal with the most obvious damage thereby 'de-ageing' the interior and improving overall presentation. 

The  example below shows a dent and a scrape on one of the rear side panels. This was rubbed back; sealed with binder solution; built back up with thin layers of leather filler; a final rub back and sealed again ready for it's new colour and finish. 

Minor Damage Leather Repair

Leather Colour & Finish

Once all the repair work has been carried out, everything needs cleaned and prepared for applying the new colourant and finishing lacquer. We use a multistage system that is top quality and allows us to get as close to a factory style finish as possible. We have the capability to match and mix the colourant in-house, but for this project we utilised our suppliers colour scan technology to ensure a consistent and original colouration throughout the whole interior. 

The final stage is to apply a finishing lacquer which provides a protective coating to the colourant; can be sheen adjusted from Matt through full Gloss; and provides that fresh from the factory feel to the touch. 

For high wear areas (such as bolsters) we can introduce adhesion promoters and cross-linker for added durability.

Leather Colour Finish

Leather Cleaning and Treatment

Any leather restoration or repair work starts with a thorough deep cleaning of the leather. We are aiming to remove as much dirt and contamination from the surface, pores, and in-between the grain and creases as possible.
Revitalising the leather if it has become dried out is essential. If the leather is dry and hard, and especially if it has already started to crack, then we need to revive it and get it back to being soft and supple before commencing any repair work so that we don't risk damaging the leather further whilst working on it.

The leather seats in this car had dried out significantly, which was a major contributor to the damage they had sustained. It took several treatment cycles to get the leather supple and healthy again. 

Leather Car Seat Cleaning

Major Leather Repairs

By far the biggest challenge of this interior refurbish was the drivers seat, with almost every panel of this leather seat needing repair work to a lessor or greater extent. From wear holes in a bolster, significant cracking, splits and tears, but we managed to save it. It has to be said that the overall condition of the seat was right on the limit of what is feasibly repairable. It was never going to look like new again (and the owner understood this) but we have successfully knocked a couple of decades off of it and have a very presentable seat again whilst maintaining the integrity of this original leather interior. 

The holes in the bolster and surrounding worn leather were stabilised with a thin sub-patch of new leather glued in behind. A new surface was then built up with multiple thin layers of flexible leather filler and sealed with binder. 

Major Damage Leather Repair

Interior Installed

Here we see the leather interior reassembled and installed back in the car. The transformation is "stunning, just stunning" as described by the very pleased and slightly shocked owner at how well we had been able to restore this interior. 

BMW E30 Convertile restored Interior