One month later.. and time to do a little catching up..
With tennis-elbow stopping play last month ..I redirected my attention to restoring my Sunbeam S7 motorcycle. But over the past weeks I learnt that hydrochloric-acid cleaning of rust off a panel needs to be done and then painted - in a single schedule of work.
The lesson I learnt here was ; to do the rust treatment / cleaning surface rust off the panel on one dry day, immediately dry it with clean cloth, and then store those panels in a warm dry place (in my lounge) overnight (to dry out any damp in the panel's seams). And the following day, after the sun has warmed the morning air - get on and paint those panels. Otherwise they will rust again (..even in the garage during a spell of dry weather) ..and you have to do it all again !
I had understood that Jenolite (which uses hydrochloric-acid as its main ingredient) was supposed to make the metal inert so as to not rust easily again. Apparently raw hydrochloric-acid doesn't do that. Anyways up..
Having likewise weld-repaired and rebuilt the front RH side inner wing's edge flange, and encasing that in fibreglass, I've now cleaned off their surface rust and painted them inside and out with epoxy primer. And then yesterday with 2-pack polyurethane paint by Hempel. This is the paint I used when hand-repainting the deck of my fibreglass boat, and I'm happy with how it works (painting with it), how it looks when dry, and its durability.
^ epoxy primer undercoat going on. I've decided that I cannot afford the time to get a smooth finish on the inside panels and so I'm going to try and leave a deliberate mottle finish on them ..with a 2" fine hair roller (in corners I use a brush to scrub the paint in).
Extra work was required on the front wings and the headlamp/grille panel ...
^ the outer front RH side wing had clearly been the subject of a fender bender. Most of the dent had been beaten out and then filled over. Still for a 40+ year old car's front wing it really is in solid condition. And in fact someone had done a pretty good job of reshaping the panel .. very much better than a block of wood or chicken wire with bondo over it.
^ filled over and painted.
^ in the process of the paint being chemically stripped, and of course also the filler.
^ sodding filler took three applications of paint stripper even after the paint was off. It had to come off though, as I wanted to try and get a better shape.. And you can't (successfully) panel-beat a panel which has bondo in it.
^ finally ! Here I'm already starting to reduce the high lumps, with hammer and dolly. It'll take a time but it's the best I know how to do.
^ It doesn't look that different I know (..not least because I've deliberately taken the photo to show its surface !) but I've reduced the dents from 1/4" or more to less than half that.
One-quarter of an inch doesn't seem very much anyway ..and had that been 1/4" of very gradual dip over a six foot panel then it would barely have been seen, but a localised 1/4" deep dent over just six inches of panel (or between hammered out places) is really very noticeable. With a little extra time & trouble that can been usually be chased / dressed out with hammer n' dolly to 1/16" or less ..and then such a shallow skim of body-filler will flex with the steel panel ..and not flake off nearly so easily. However with panel-beating you have to be wary - not to excessively beat the metal ..as that will stretch the surface. And then you end up with a bulge.
So the trick is to use a dolly on the other side to where you are lightly tapping the high points of the lumps down. The dolly is not flat though. It is shaped with a gently round upper surface which with careful positioning & rotating can be made to sit down flat into the inside of a curved (compound shaped) panel. The idea being to bridge the nominal level surface with the dolly and then to tap (from the other side) the panel's lump down to that surface. The flat side of the dolly is used on the outside of the panel when tapping the dents out from the inside (which on the inside appear as lumps).
^ Dollies come in different shapes and sizes and are shaped according to use. This one has relatively flattish curved surface for laying to the inside of flatter compound car panels. Some are very much more rounded to fit into the top corners (for example) of a car's wing, whereas others are shaped to fit well around a wheel arch. But this one is a generally all round useful one ..with both hard and soft edges used as appropriate to support into tight corners (such as a relief line along a panel).
NB. I use the terms 'laying to', 'fit into' and 'supporting' ..which I hope helps you realise how they work.. ie. by laying flat to the nominal level inside even a compound surface, so the high points can be tapped down from the other side to that level.
I can't remember when I bought these tools ..sometime in the early-1980's I'd guess*, but even though they are a little scarred now, they have served me well over the years. I'm sure good old dollies can be bought at an autojumble nowadays. But.. avoid buying a dolly which does not have compound curves. Some I have seen from China appear to have a round surface along a single plane rather than compound curves, whereas many are just too rounded to lay flat / fit well inside the gentle curves of a car panel ..perhaps they are intended for the tighter inside radii of motorcycle mudguards ?
p.s. * Ah ha.. I recall in '79 or perhaps early 1980.. I was working for Tony Stevens in Warwick and one evening went to an open air concert (with parking on the grass in the park) I was driving my Vauxhall Victor FB and in the darkness thereafter drove off with its crooklock still on, around the brake pedal ! We drove a gently arc until I bumped into the back quarter of a mini ..at tick over speed, which just pushed along until our engine stalled. (NB. I obviously didn't have the quickness of mind to have just turned the ignition off !). Anyway, the rear light panel of the mini crumpled in (no damage to the Vauxhall) ..and rather than drive off I waited for the owner to return. I agreed to personally repair his car, in lieu of adding to my youthful insurance premium. So, I bought these tools (new !) to repair that (..in the owner's front garden). He was so pleased.. that he asked if I would do other repairs on the car. I politely declined as it wasn't how I wanted to spend my weekends.
You'll also note that despite the age of these tools - their faces are still kept reasonably blemish free and clean. And that's because any blemish tends to get 'stamped' into the metal's surface (especially if working with soft metals like aluminium, copper or brass). The old ball hammer was my fathers. I have no idea how old that might be, but just occasionally I use it in my panel beating, again just where it fits tightly..
So again : Work in turn from one side of the panel and then the other - always tapping the high lumps (which are dents when seen from the other side of the panel) down to the nominal / mid level.
Hope this has been a useful quick guide to 'chasing' dents out of metal
^ no filler, just a coat of epoxy primer.
^ coarse rub down with 240 grit.
Next.. required a bit of work with the welder, as the return flanges of this front wing were cracked in two places and buckled in others (so back to hammer and dolly). Likewise the car's front (grille) panel.
^ work in progress
^ This was dented / buckled straight in perhaps 1/2" but very locally. The grille was undamaged so either it's been replaced or we were lucky. Above I've straightening it perhaps half way.. another 1/4" to go I'd guess.
There were so many dents, cracks, bend and otherwise buckled edges, that I can't show even a small percentage of them, but each have / are being addressed with welded repair and hammer n' dolly as required.. Until . . .
^ shaped without any filler (..yet)
And of course, the insides of both front wings and the inner panels have now been painted in the 2-pack polyurethane . . .
So not a great deal of progress for a whole month, but then as I say I have been doing other things too.
Hope that is of interest,