Lead Loading the welded areas and arches.
Lead loading has a bit of a mystique about it but its really quite straightforward if you take reasonable care and follow the process correctly.There are plenty of videos showing techniques but this is how I do it and reading this in conjunction with a video may help those who want to try it.
First off an image of the kit you would need for those who choose to have a go!
Moving clockwise we have paper sheets to catch the lead that falls or is filed off , this can be melted back down and used again, although the cost of the sticks is expensive it is cost effective as the dross can be recycled
The blue cloth is close woven material,roller towel, cut into 1ft long lengths and soaked in water,this is used for wiping over when tinning. If you can get plumbers moleskin then use that as it doesn't pick up the tinning and makes for a much neater wipe, sadly I was not able to find anyone that knew what the F I was talking about!
So I used roller towel.
Next is the sprayer,. This has a solution of washing soda mixed into warm water and I will explain why you need this later.
Then we have the paddles in a baking tray of tallow. These where cut from an oak floor board and shaped up with an angle grinder. Any close grained hardwood is OK for this, melt the tallow and soak the paddles in it overnight so the fat gets into the wood then burn the ends.
The blowlamp a neat tool this one,it self ignites and extinguishes immediately so it is very useful when you need to ditch it and use both hands.
Then there is the grinder that has a paint stripper wheel attached this is used to buff up the surface first.
Then completing the circle the lead sticks themselves. These are 70/30 lead and tin. The tin gives the material better amalgamation and adds a bit of "hardness" so not as soft as 100% lead then.
And that is the stuff you need to get the loading done.
The peculiar shape hammer on the floor has nothing to do with this at all it just got itself in shot. It is known as a Donkeys Dick, Cannot think why, just traditional I suppose.
https://goo.gl/photos/kB7hZr5EEuvdMgPNA
Preparation
You need to take care in the prep. Using everything you can chuck at it clean the area thoroughly removing any slag and oxides from the weld beads and surrounding areas. Here I use a paint wheel,wire wheel, sand blasting, followed by a thorough wash out with panel wipe or thinners.
If you dont get this bit right then you will have problems at the tinning stage.
https://goo.gl/photos/QN9YbQbt7BfYoX1F8
Warming and application of solder paint.
After the solvent wipe warm the whole repair to an even temperature. not hot but just comfortable to keep your hand on, this will chase out any old solvent or moisture in the weld beads and panel and help with the solder paint.
Next paint on the solder paint make sure you go beyond the area you want to lead.
https://goo.gl/photos/Qpx4aQ518a4Y4jFL9
Tinning
You are going to be getting the panel hot and distortion can occur if your not careful. It is a good idea to keep a larger area than you are working warm this will help counter any distortion, don`t be tempted to quench the panel/lead if it does distort you will likely make it worse, move on to another area and the chances are it will sort itself as it cools.
Using the torch bring the area up to temperature working about a foot at a time. I start at the lower edge but it is your preference as to where you start. For the sake of the post I have started in the center!
Warm the area until it starts to go as in pic one the grey paint starts to look like a galvanized patch, keep the heat on wafting it over the area until it sweats silver beads and a sort of toffee apple floats ton the top no hotter or you may burn the tin off.
https://goo.gl/photos/L7jnD3kEX3oL9x9S6
There is no need to melt the solder paint until it runs off but some prefer that method. Now using your damp close woven cloth wipe the area over, you will see a bright almost chromium surface appear this is the tinned surface, work about a foot at a time.The cloth will likely pick up bits of solder so turn it frequently or go to another piece if you need.
Move swiftly along to the next section repeating the process and wipe from the cold edge into the just tinned area. Continue this until you have wiped the whole area.
Should be something like this.It looks scruffy but its fine there are no dull areas and that is what you want.
lf you have dull patches it likely means the prep wasn't right or temperature was not hot enough, let that bit cool re-apply the paint and go over that bit as before.
https://goo.gl/photos/MEdHARoDyGsZWNeP6
The next bit is crucial but is often missed .
Now the area has been tinned it is very important that we remove any remnants of the solder paint. Solder paint is acidic and if you dont get this out or neutralized at this stage you will have early failure of the repair.
Simply the acid will eat away at the steel and the first you will know is when you see a raising of the lead work by which time it will probably have penetrated through the steel panel and you are back to square one again.
So this is where the sprayer comes in. I use washing soda two desert spoons to a 750ml bottle of warm water . You can use Baking soda or any alkali mix.
Spray it into the the crevices and joints . You cannot do this too many times!
Just apply it give it a little time and then do it again at least five times
.
Finally wash it down several times with warm soapy water, blow dry and warm the panel back up to chase out any remaining water.
Acid corrosion is a common reason for failure of lead work.
https://goo.gl/photos/EEddALEJdCDFGSBS7
Now the fun begins.
Your floor paper should be nice and wet now that is fine as it will be catching any drop off of lead from the loading.
Here is the tricky bit.
You need to warm the tinned surface and the stick of lead at the same time. Your looking to get the stick "stiff plastic".
If you look at the tinned area it will be grayish from the soda solution and when you you start to see this becoming shiny that is an indicator that it is at the right temperature to receive the lead.
You must amalgamate the stick lead to the tinned surface to ensure proper take up so the two things need to come together temperature wise at the same time, the heat of the stick needs to be right as does the tinned surface. So heat the two equally.
When the temperature is correct is correct you rub the stick into the tinned area working about 5-6 inches at a time pay particular attention to the weld beads.
You have control of the heat if it starts to run pull the flame away.
Carry on around the arch like this.
Now allow the area to cool off a bit, melt the tallow in the pot and get the paddles ready to use. Start back at the beginning with the same process of heating the tinned panel and the lead stick. When you see the stick become plastic push a lump onto the panel and sôrt of snap it off do aboit 6 inches at a time. It doesn't matter what it looks like at this time you are just loading the panel with the right-ish quantity of lead.
Remember you have control of the heat if it starts to drop pull away the heat and push the lump back into where you want it.
Now heat the loaded lead to a plastic state and push it well into the weld bead and then an approximate contour with the paddles.
https://goo.gl/photos/PCwnwk7LHwyqc7cK7
Keep dipping the paddles in the tallow else the lead will stick to them and drag your work..
https://goo.gl/photos/K19e8Kh82P3BaRse9
Dont worry about smoothing it out you will be doing this this with the body blade when we come to shape the repair. Carry on around repair like that.
If you have a low spot then you can just reheat and add a bit or drag some from a high spot across.
You should end up with something like this.
https://goo.gl/photos/ZMQ78EJ3UfzqRMxo6
Allow the work to cool once you are happy that you have enough material in place.
Pick up the paper sheets and collect the fallen lead into a pot.
Wash off the whole job with thinners or panel wipe to remove any tallow. You dont want this being filed into the work or you will have problems at the paint stage later so brush with copious amounts of solvent and wash it down with warm to hot soapy water after.
Put down fresh sheets of paper to catch the fillings and you are ready to start shaping the lead with a body file.
My preference is for a busted half round blade.
https://goo.gl/photos/VY4Y5bDEAdGDUwzz9
I am using the lead to cover weld joints so I will be finishing with polyester stopper before priming.
The point of leading is it amalgamates with the steel it will flex with the panel as steel would and will not separate it can be dressed when cooled just as you would a steel panel, pinning and filing if you wish too.
Here it is washed down and ready for leveling
The lead reclaimed will be cast into thinner sticks.
https://goo.gl/photos/txu2Wkc5APau8Rp5A
Now watch a few videos for the torch technique.
Good luck!
