How to Lead loading
Black art or something you can do yourself? We find out on MBVR’s Mk1 Granada restoration.
In our bodywork series, we’ve tackled replacing the rear quarter on a Mk1 Granada and in so doing, uncovered one of the traditional areas of the craft that you’d think was forgotten — leadloading — simply because it’s old-school. The seams where one panel joins another often deliberately had a step in them, which was filled with lead and blended in. You’d think that with modern body filler being so good, the practice has been relegated to history but it appears that some things were simply right in the first place and there’s still no proper substitute.
Lead is still extremely good because it’s flexible and can cope with the slight amounts of movement that could crack body filler which, by comparison, tends to be more on the brittle side. Therefore, the practice certainly isn’t dead and is still used on new cars today. But, it’s moved on, especially in the materials that are used. Our partners in this latest series, Mid Beds Vehicle Restorations, (MBVR) still uses such traditional methods and demonstrate to us, exactly what’s involved. We followed along as their lead man, Robin shows us how to fill a seam.
In theory, these are two separate processes — fluxing chemically cleans the base metal, which then allows you to apply a very thin layer of lead, known as tinning.You can apply the bulk lead in the form of sticks that will then stick to the metal, but without either of the processes — fluxing and tinning — the heated lead will simply roll off onto the floor.
Applying the lead
We’ve been using phrases such as body solder because the term, leading is a bit misleading — you aren’t actually using straight lead. What we’re using is an alloy of tin and lead, which resembles the stuff you use for electrical soldering, but which can’t be used here.The ratio of tin and lead determines how hot it needs to be to melt it, thus there are solders for seams and lower-melt solders for areas which are likely to warp under heat.You need a lower one to risk damaging the panel you’re trying to fill.
Smoothing
We’re going to smooth and shape the lead we’ve applied to the panel. For this you need shaped blocks of wood – usually Maple – called paddles.There are various shapes but basically, use a flat one and a curved one.The surface is gently heated...