In order to reap the rewards of driving an old car, you need to accept the maintenance obligations. This mostly entails making sure that various components either move or remain static as appropriate, but the leading cause of distress and financial inconvenience must be the curse of corrosion. Look under any old car and you’ll find it’s almost designed to trap mud and grime which will build up in the cavities and work its way into the seams. The damp will set in and rust will soon take hold which, if left unchecked, will have the body peel to the ground leaving you with merely a seat and a steering wheel like a clown’s car at the circus. This is undesirable.
In order to avoid this state of affairs you need to keep on top of things, especially if your car gets regular or hard use and particularly in the winter. When I bought my BMW 2002 rally car it was in full clown car condition and a significant amount of new metal was required to save it from the scrapyard. It pays to take precautions against a repeat of the decline. I make a point of thoroughly cleaning underneath after every event but it was time for a freshen-up. The floors remain straight but the chassis legs have seen a bit of action and there is no shielding for the inner wheelarches, the 2002 coming from a time before plastic arch liners. Inevitably, these high impact areas were showing signs of gravel rash but my tactic of thorough cleaning and preventative maintenance had been worth it. On balance, it wasn’t that bad but it was definitely time for some attention.
When the car was first rebuilt it was treated to comprehensive layers of primer, stonechip and topcoat which have done pretty well in preserving the body. As a precaution against the places the spray gun couldn’t access I pumped Dinitrol into the sills and then subsequently discovered Dynax S50 which has been injected absolutely everywhere else a couple of times since. Squirting the flexible lance is a satisfying activity and seems to have been well worth the comparatively minimal expense with all of the box sections remaining rock solid. With no structural rust to contend with this time, I only needed to reseal any compromised areas but you can’t just slap anything on and hope for the best. As I hardly ever say, if a job’s worth doing, it’s worth doing properly.
I rent a reasonably sized workshop where I can take my time and it’s important not to underestimate the time required for preparation. After its last event I got the car up on stands on my driveway and jet washed underneath but stubborn mud lurked in the many rot traps that BMW thoughtfully designed in. I use the word “mud” to dilute the horrible truth because what I really mean is a coating of toxic green cow-eggs from a particularly unpleasant field in Leicestershire. This particular waste product dries rock solid, resists the jet wash and stains paintwork. Unpleasant. Once in the workshop I raised the car up on stands again for a final scrub and degrease which took considerable effort and can be directly linked to the disappearance of all the dish brushes from my kitchen. After spending so long lying down I needed to go for a lie down before the next stage.
This tale might now start to read like sponsored content extoling the virtues of Bilt Hamber products, but it’s my own money that has changed hands and you can be sure we remain impartial. I’ve previously tried all manner of well-known stuff and been disappointed but Bilt Hamber products seem to be consistently effective and this will be a good test of how they stand up to harsh conditions. With the hull fully clean I tackled the areas where the old paint had been scuffed off and the metal exposed. It probably looks worse in the photos than it was in reality but a thin layer of surface rust had formed so I set to work with the Deox rust removal gel, a product that sounds like snake oil but actually does work. Basically you just trowel it on, cover the treated area with cling film and go to the pub for a couple of days. When you return you can peel the cling film off and agitate the rust away with a stiff brush and a squirt of de-greaser. Frankly, it works a lot better than expected and I made sure to get back to shiny bare metal where I could, whilst using a rust converter for good measure elsewhere. I left any undamaged paint in place, save for giving the underside a good going over with a wire brush to deal with any flaky areas. Working upside down in the gloom is no fun and I impressed myself by sticking at it but the memory of galloping corrosion is a strong motivational tool. You may wonder why I was working in the gloom but I should explain that corded inspection lights seem to be a thing of the past so I am forced to use a rechargeable LED thing that gives three minutes of light for every seven hours on charge.
After the rust treatment it was time for two coats of Electrox zinc primer and the job started to show some visual progress. I somehow managed to get primer inside my gloves and up my sleeve, so including me, I covered more surface area than expected. With the Electrox dry I shuffled around looking for any places that would benefit from further seam sealing but apart from the spare wheel well there were only a few inches that needed attention. I don’t see the point in running sealer everywhere as if it gets compromised and damp gets in behind, it create problems. It’s better just to inspect regularly.
Time for the main event now, the Epoxy Mastic. The product comes in two parts, a large tin of inky gloop and a small tin of clear hardener. As the temperature was around 10 degrees I warmed both tins for a few minutes on the cam cover of the car I’d arrived in and then poured the hardener into the black gloop, stirring well and leaving the cocktail to settle. I pulled on a fresh pair of long marigold gloves and dipped my brush, turning it upwards to meet the floor pan whilst the mastic ran straight up the arm of my jumper. It’s a curious product, simultaneously offering good coverage and easy creep whilst being unfeasibly sticky. Soon the brush had become irretrievably glued to my glove and I was glad I’d put a tarp down or the workshop floor would have been a lost cause. It’s serious stuff and doesn’t wipe off easily. I had enough for one good coat and a bit of strategic recoating before the tin was expended but once dried it looked fantastic and feels very hardwearing. Epoxy can chalk on exposure to UV light but that shouldn’t be an issue underneath, so I’m not going to topcoat for now but I will keep an eye on it. All that remained was to add some colour where appropriate so I built up layers of Chamonix white in the high impact areas inside the wheel arches, especially at the rear where the stones really fly. Finally, I applied fresh Max Meyer two-pack to the rear valance and the outer sills, and called it done.
After such an amount of work, it seems a shame to get it dirty again but at least I can do so with a clear conscience that I’ve done the best job I can with the equipment I have. You can’t really have too many coats of protection on the underside and its bad form to let cavities become a breeding ground for grot. I’m going to hope the products I’ve applied will work as intended but the best way to test that is to use the car in the manner it’s built for, and I’ve got a quite a full diary already. Time to hit the road once again.