The Bonnet and Hinges
Some background information is in order here before we start. The bonnet hinges on this
car are scissor type devices. Each has two very strong springs whose main purpose is to
hold the bonnet up when raised. A secondary purpose is to hold the back end down when
closed. For that, they pass an over-center point at about 1/3 raised. The photos show a
hinge in the raised and lowered positions. With the hinge/bonnet open all the way, the
main leg of the hinge is almost straight. It appears that it could almost hold the bonnet
up without the springs, almost. Anyway, it takes some effort to start closing. In fact,
it seems impossible to close the hinge by hand if the bonnet is not present. You have
to spread the hinge legs about 1/2 inch with a screw driver before you can then push it
down. Note that the hinge may not actually get quite so low in the closed position with
the bonnet attached.
The almost four foot leverage of the bonnet, however, provides a lot of torque at the hinge. If it still resists, more force can do great damage. It seems this may be a common problem with these cars. Some DPO did exactly that and distorted and ripped some of the hinge mount area of the bonnet. I discovered this right away when I first got the car. It was almost a two-person job to close, one to pull down at the front and another to press down on the bonnet over the hinge. I figured out that I could close it by pulling down at the front while pressing down only on the left side hinge, a bit of a reach but it usually worked. This was the routine during most of its active life.
At some time I decided to just remove the springs and rely on a shop made prop rod to support it when open. That was its condition at the 1998 All British Car Show, photo. The problem with that was the lack of the springs holding the back down allowed it to bounce around a bit. So, I decided to put the springs back only to discover that I could not find them. After some quite considerable time and searching, I gave up and bought a new set. By the time I got the new ones installed, I found the old ones. Funny how that always seems to work out.
Looking at what is almost surely involved, including removal of the hinge mounts from the bonnet before straightening the skin, I was always a little intimidated by the job, unsure of my sills or ability to accomplish it successfully. After my work on Dick's Model A cowls, My Sprite wing and the Prefect rear apron and boot, I think I have learned enough to handle it.
The bonnet had been off for several months to give better access for working on the wiper motor and its switch mechanism here. I put it up on a work table and began removing the spot welded hinge mount panels. There is a bonnet stiffener across the back, shown in the photo below. The back edge of the mount panels is spot welded to that. The other edge is spot welded to the bonnet skin where folded under along the sides, also in the photos below. The first photo shows the left hinge mount with the bonnet upside-down on the table. From where the outer edge of the mount attaches to the stiffener until it begins to curve toward the bonnet side should be almost a straight line and should almost touch the skin. As shown, it has been bent and distorted leaving a gap of well over half an inch from the skin. The second photo shows the same mount from the other side. Although not distorted as bad as the other side, again it should form an almost straight line and should almost touch the skin. The third photo shows the stiffener across the back with the mount panel removed and a break and bend in it at the outer edge of the mount. A similar break appears on the other side.
The next set of photos show the right side mount, before and after removal. Comments for the before photos are much the same as for the left side although this one is not quite as bad. The mount after removal, sandblasting and partial straightening shows a welded break just forward of the hinge location and another on the far side near the back of the hinge location. The spot welds along the back stiffener were all pretty clean and drilled without incident. Those along the sides were a different matter. Apparently the forward two on both sides broke or tore in the past and the DPO rewelded them but with a torch, not a spot welder, in the bent and distorted condition, and not very well done. On the right side, several of the rearward spot welds received the same treatment. The skin will probably require new metal at that location. You can sort of see those sloppy welds in the left photo.
Meanwhile, I sat the bonnet back in position on the car to check the fit, primarily at the scuttle. The photos above don't show it but there is a crack in the stiffener across the back that has been welded but not completely closed first. I wanted to discover whether that would have to be broken, reshaped and rewelded, probably as the first repair step. The first photo below shows a good alignment as is until the ends where hinge distortion appears. The next photo indicates almost correct alignment between the bonnet and side apron on the off side, again until the rear and hinge distortion. The near side is not so good as the gap is much wider. Most of that appears to be caused by a distortion in the bonnet panel that mates to the slam panel. I suspect at some time the latch did not release and someone had to pry on it to open, resulting in a bit of a bend in that panel. Unfortunately, these photos do not adequately show the amount of distortion.
After a long break to finish the Sprite assembly and work on the Prefect wings and doors, I finally got back to the bonnet. First thing was to strip the old paint and filler, of which there was a significant amount on both sides. Most of that was done with 80 grit on the D/A and polycarbide disks on a die grinder where the D/A couldn't reach. Next was to rough straighten the back-outer corners where the hinge problem had significantly distorted them. This proved to be easier than I expected, using a round faced hammer from the inside and just my hand to backup on the outside. They still need some dolly work with the hammer to finish but they are at least close to the right shape. Next I tied a rope across the back to pull the ends in approximately where they belong and to close the gaps in the broken rear stiffener. With the setup, I welded the breaks, removed the rope and test fit it to the car. It was better than I had hoped. Everything looks good except the rear corners are a bit too tight against the scuttle. this should be easy to fix. The photos below show the results.
It is time for an aside here. I have been giving more thought to the hinges. I think I mentioned somewhere that the hinges actually appear to be all right, not loose and not worn so as to open too far. If not, I am doing it now. I suggested above that this may be a common problem but in retrospect, I can't really say that. These cars are quite rare so I have only seen a very few, a couple in salvage yards where I found some parts and the rest fully restored street rods. I get a monthly news letter from a club in New Zealand and it doesn't seem to be common there. There is an owner on the British Car Forum who is restoring one his father bought new and his works fine. I now think it is more likely that a wind gust caught this bonnet up and blew it back against the body, distorting and probably even tearing some of the sheet metal or brackets. Getting it back down, the PO then did further damage. Another possibility, of course, is the bonnet blew up while driving down the road. That seems unlikely due to the way the latch works on this car. That is, again of course, unless the PO forgot to latch it which is a manual operation. In case you have forgotten, PO refers to a previous owner. With that realization, maybe I will be less concerned about how I will deal with the hinge operations in the future. Now back to work on finishing the repairs.
So back to the work. After welding the breaks in the stiffener, the ends were a little too tight fit at the scuttle. Although this looked like a simple fix, it was not. With me holding that side of the bonnet flush against the table, Dick Pulled the near side corner just enough to get that side right. Trying the same on the other side broke my torch weld. I welded it again with the MIG this time and tried again. The MIG weld also broke. I thought maybe the metal was fatigued enough so even welded it could not take the strain. It seemed that a reinforcement might be the answer. I started shaping one but found getting it to fit suitably was not going to be easy. Instead, I got the corners positioned at the proper spacing then welded the break again with the MIG. This time I added some extra material and ensured that the crack was completely covered. The spacing held and it fit the scuttle properly. I declared it finished.
Next thing to do was finish repairing the hinge brackets. I thought I had them pretty close as stated above but I was wrong. I really couldn't get a suitable photo so you will have to use your imagination and try to visualize the following description. The outer edge, where they were spot welded to the bonnet side is fairly well undistorted. If I could have mated that edge properly to the side, the long point of the edge that welds to the rear stiffener would have had to extend two inches or more through the outer skin and the shorter side of that edge would have been about two inches short of touching. In other words, after removing all the obvious bends and repairing the cracks, they still had about a four inch twist that had to be taken out. And, all this had to be done while maintaining a reasonably close alignment to the four bolts attaching the bracket to the actual hinge.
The way to repair this was a long, trial-and-error method. First determine what might be the next step then put it in the bench vise and try to make the corresponding bend by hand. The metal is 3 or 4 times the thickness of body metal. Next take it back to the bonnet on the work table and check the progress, if any. Then repeat the process until it fits. It took a good three hour morning for each one. I don't know how many trips from vice to table were required but probably a few dozen. I probably walked at least a half mile for each one.
With this all done, I could clamp the brackets to the outer edge, aligning the original spot welds then check the fit at the back edge. In fact, this was the method used throughout the straightening process. In the end, the back edge spot welds all aligned and the inner point just touched the back stiffener as it should. The outer corner of the bracket on both sides was about a fat 16th of an inch short of touching. I declared that good enough as it took little effort to close that gap.
Next step was to weld them back onto the bonnet. I was a little concerned for the possibility of either burning holes or not getting adequate penetration since I could not see the under side of any of the welds. This turned out to be not a problem after all. I did work in small steps to avoid any over-heating problems although the brackets are fairly heavy and this is not visible body skin. The photos below show the final result, first the near side then the off side. They show first the bracket itself then two angles showing the alignment at the scuttle.
