The outer layer of alclad is pure aluminium and you cannot get much softer than that, your other problem is blasting by it’s action forces corrosion deeper into the material…….. the blasting material does remove metal, that iw why the surface becomes textured as you do it, it also distorts thin materials such as skins…… I have seen what looks like perfectly good skins punctured and destroyed by shot/bead/glass/ice blasting, when you can do the job chemically without any of those problems……

Granted the outer skin of alclad is alu, probably more in a T6 state than as soft as “pure”,and I’ll also agree that the wrong media can and does damage thin alloy, but if as you say blasting does not remove metal, how can it “drive corrosion deeper into the metal”? what is happening, is that if you use larger particals of grit, they are unable to get into the microscopic crevices, and smaller particals are invariably softer and cannot remove all of the corrosion, before degenerating to powder.

This is the Newark air museum your talking about, and not the scrap yard adjacent to the A1 (with the lightning )?

Hi Peter, using a fine blast will be ok, some companies these days use Dry Ice BTW as a medium, once done the Ice melts back to a gas leaving no residue, A lot of companies beadblast Aircraft corrosion but if the material is thin and the corrosion deep it can take a lot of material off, it can also “stretch” the material , I was told by some painters that with alloys been softer it can push some of the corrosion deeper into the material, but saying that a lot of companies still use it, chemically treating it is just less invasive, especially on older Aircraft and thinner materials. I do still use it in areas on our aircraft, but if I can I use chemicals these days, you can see when it’s killed the corrosion as all the black spots will be gone. Remember though Alclad has a thin layer of pure aluminium on both sides, this acts as a sacrificial layer and like Zinc coating “self seals” over scratches etc protecting the alloy underneath, when treating corrosion this is often lost, so you need to replace it with something such as paint etc

Do read the FAA link I gave you, it is very good and full of lots of information, indeed there are paragraphs on most things, wood, fabric, repairs, electrics, welding etc. It is a goldmine and free

Its a good job “some painters” told you that, if it were a metallurgist we’d be in trouble; I suspect that their experience was that the metal wasn’t blasted properly, and that corrosion remained, covered by deposits left from the blasting media,(as some soft compounds do) and once painted, reared its ugly head again.

For what it’s worth, I’d go with Bruce’s suggestion, there ain’t a screwdriver yet that a 4.5″ grinder can’t sharpen! when reshaping the tip, it is important that the sides of the blade are ground square i.e not tapered, and the ends radiused correctly; the real problem with these screws, is that (when rusted) there probably isn’t anything that will move them, and the will have to be drilled out.

Or hollow ground as John (above) has said.

The dog’s name may well be trivial, but the fact that “we dare not speak it’s name”, is not.

I have a strange feeling of deja-vu, all over again….

A couple of things to look at, are the points gaps set absolutely spot on, with a narrow gap the engine will run but is reluctant to rev, are all the plugs sparking? (these engines foul plugs when not running under load, or idling for long periods) check the colour of the deposit on the plugs sooty is too rich, no deposit is way to lean, light brown is about right, if the mixture is set correctly, and the pug colour indicates weak mixture, you probably have an air leak.between the carb and the heads (somewhere); Merlin Pete is really your man for this, I believe he once had a misfire that turned out to be a dropped valve…..

Firstly, there can be no comparison between the Vulcan and Sally B. Sally B has operated successfully for many, many years, and this is the important bit, operated as a flying Memorial to the many thousands of men of the United States Army Air Force who died in the cause of the liberation of Europe. It’s a sad fact that Sally B’s problems would be resolved at a fraction of the costs incurred in the restoration and ongoing maintenance of the Vulcan.

I can’t comment on Sally B’s mechanical problems because of the simple fact that I’m not party to that information and I strongly suspect that even if I were I wouldn’t understand it. Some 88,000 USAAF airmen died during World War Two, IIRC somewhere around 50,000 in Europe alone. I know which aircraft has the greatest personal resonance for me.

Someone mentioned marketing? I suppose the big difference in approach is VTTS’s shotgun approach of give us more money or we scrap 558.

One final thought for the Vulcan fans. If the posting seen this morning on a thread about 558 is correct, then it appears the Vulcan is no more serviceable than Sally B today.

Regards,

kev35

I had always favoured the Lanc to the B17, but at the 60’th anniversary of the dams raid, the Lanc was a “no show” apparently it was too windy; Sally B however flew, and I was greatly impressed with the teams dedication, and so became a supporter, as a fringe benefit you can actually clamber aboard this A/C for free.

Tango Charlie,it is bad luck for the operators of this A/C, especially as they need the airshow (and public appearance) revenue to keep her flying, but sadly if it were just bad luck, it would be like having a stone chip in exactly the same place on the windscreen three times over, having barely got out of your drive.