Finishing off the bottom plate

Remember when I salvaged the old brake pipe brackets from the rusted old bottom plate (click here)? Well, when I went to weld them onto the new bottom plate I realised that the recessed area stamped into the repro panel was too small widthwise for them to sit in. Typical! As the original panel never had these recesses I decided the best thing to do was to cut them out and weld in new flat metal. The old recess cut out and a card template made up:

New metal (from the left over scraps of the naps hat repro panel!) all welded in:

Ground down the welds and bent the flange to match the profile of the panel. Then finished welding it up, sanded everything smooth and added a lick of primer:

Once I had done the same on the other side I located the factory correct position of the brackets (thankfully I kept the old rusted panel for reference) and plug welded them on:

Continuing on the topside of the frame head, I decided to add a solid weld bead along the small section of flange between the naps hat and the diagonal flanges. I did this in a couple of stitches so that I wouldn't heat up the metal to the point of causing distortion. Here is the first stitch cooling off:

This just left me with the front edge to sort out. After laying down the first lap weld stitch it became evident that the old metal was not holding up well to the intensity of the welder and as a result the edge blew out in a lot of places:

I managed to reconstruct the area using weld material and grinding it back into shape, but it was a long and tedious task. To combat the blow-out I used a copper backing plate on the other sections which really did help to maintain the integrity of the old metalwork. It also proved to be an effective heat sink and drew a lot of the heat away from the area:

I 'pie cut' the curved section (where the profile of the new panel did not closely match the original) and bashed it into submission with the body hammers to get a better fit:

After a lot of fettling I got a passable result:

I then devoted a bit of time tidying the entire frame head, sanded the plug welds flat and filling a few pinholes. This finally concludes the epic frame head saga. Done. Finito. Phew!

Fettle, fettle, fettle!

The time had come for the addition of the frame head bottom plate. I knew the fit was going to be a challenge with this Klokkershite panel and my intuition was correct! The main cause for concern was around the front lip which had not bent up to 90 degrees, so it caused the panel to sit further back than it should. To remedy this I cut a series of slits around the corners of the lip in the report panel to allow for easier manipulation of the steel. I gently bent the lip back so that I could get the whole panel into rough alignment. My thinking was that if I could get 75% of the panel to fit satisfactorily then I could fettle the rest using the persuasion of my body hammers. I spent A LOT of time on this - checking, measuring, making small adjustments and rechecking etc...

I unclamped the bottom plate and began my final preparations before welding it on. Once again I coated the inside of the framehead and naps hat with some FE-123 and once it had dried I mixed up some Mastic 121 and coated the inside for extra rust protection. Also stripped part of the bottom plate with a wire cup and gave it a lick of 121 in the middle and zinc primer around the edges to be welded: 

before permanently sealing everything up, I bent the last section of the new fuel line into place so that it exited through the correct hole in the top of the frame head:

I cleaned up all the framehead flanges and gave them a decent coat of zinc primer:

Drilled out a series of 8mm holes for plug welding, to emulate the factory spot welds:

Starting with the centre of the spine I added the first few tack welds. I then filled the plugs along the Naps Hat flanges before filling in the rest of them on the underside:

To ensure a flush fit in the hard to reach areas I invested in a deep throated G-clamp, which really did the trick here:

Got very positive signs of penetration on the top side. In fact I probably could have eased back a little on the power settings, but at least I know these plugs are super strong:

The bottom plate is almost there now. Just a few tweaks to make along the front edge, a couple of seam welds to add and the brake line brackets to reattach. 

More updates to follow shortly...

Bottom plate removal

Using a wire wheel attached to an angle grinder I cleaned off most of the dirt and surface rust from the frame head. This allowed me to see what I was really dealing with in terms of the metal work condition. Thankfully the frame head looked fairly solid despite being pitted in places. The same could not be said for the bottom plate which was in a sorry state. I agonised for a while as to whether I should try to patch it up or simply cut it out and replace with a repro panel. I choose to cut it out and replace as it was the more thorough option. The added advantage is that with it gone I will have better access to the front of the chassis tunnel. In the near future I intend to clean out all the accumulated rust flakes, dirt and grease from the inside the tunnel and then treat it with Waxoyl or similar to seal evering up. Anyway, I started by cutting around the spot welds:

I then switched to the angle grinder and ground down the seam welds along the front edge. It was quite a long process, but I was deliberately going slow to ensure that I did not damage any metal that I wanted to save:

 

 

For the smaller areas and tight corners I used a Dremmel, which I found to be surprising capable:

Here is the bottom plate starting to come free. Note the area at the top of the image that I separated by 'thinning' the metal of the unwanted bottom plate until it could easily be broken free:

So, after a few evenings of intensive cutting and grinding the bottom plate was off:

A comparison between the old panel and the repro one that will eventually be welded in:

I have heard other people mention that taking off the bottom plate is no easy task and they were certainly right! It takes a lot of persistence and at times I felt frustrated, but I resisted the urge to cut corners (both metaphorically and literally in this case!). I am feeling pretty good about the result as none of the metal that I am trying to save was damaged by the clumsy use of power tools. Slow and steady wins the race! 

Now I need to grind down the rough edges, clean everything up and straighten up those flanges.... 

Spot weld cutting

Well, as you can see from the picture below (taken a few weeks ago) my framehead bottom plate is in a sorry state, particually on the drivers side. Just look at the size of that rust scab!

 

Thankfullly the rest of the frame head seems pretty solid so I have decided to cut off the whole bottom plate and replace it with an aftermarket panel. I will then clean up the rest of the frame head, which should only need minor repairs (if any). I am keen to retain as much of the original metal work of the car as possible and figured I would salvage the brake line brakets and graft them onto the new panel. I have heard that the ones that come attached to the replacement panel are flimsy and utterly crap, so I think this will be worth the little extra effort. I have circled them in red below:

Flipping the pan back over I started out by wire brushing the area below the brackets and then lightly sanded to reveal the location of the spot welds. As you can see there are 3 distinct spots under each bracket which needed to be drilled out:

 

This is the spot weld cutting bit for my drill that I opted to use. Basically I used a centre punch to create a dimple in the middle of each spot weld then placed the spring loaded guide pin (the protruding part you can see on the left of the photo) into the depression:

Working with the drill on a slow roatation I steadily cut through just the top layer of metal:

 

Then gently separeted the bracket from the old panel:

 

 

I then clamped the piece into a vice ready for grinding down the excess weld material:

Here is the piece after grinding. Now it just needs cleaning up and a quick lick of paint to keep it from rusting until the time comes to attach it to the new panel:

Now that I am practiced in the art of spot weld cutting I better crack on and drill out all the little buggers that are holding the bottom plate in place...