An explosive solution to a workaday problem...

Forgot to mention that the half-circular failed brazing experiment did not go to scrap - we made a very large dial thermometer, using it like the Bourdon tube in a pressure guage. Waste not, want not...

Could you please finish the quote at the end of your last entry before it drives me nuts?

Sorry, this is obviously too long for a sig. "Intelligence is like having a big boil in the middle of your forehead - it doesn't make you any happier, it doesn't make you any more attractive, but it does give you something to talk about..." This comes from Judge "He ain't heavy, he's the Law !" Dredd, in the 1980's. Quote from Venus .... I'll look around for the source...

Gotta love Judge Dredd. I worked on the movie with Stallone when I was thinking of going into special effects for a field. There is a field with tons of problems like the one you were talking about. Great post though.

Ah, didn't know there had been a movie, I'll look out for it... Googling around leads me to believe that the quote was from Halo Jones, but I can find no direct reference. The Zarjaz 2000AD Comic was so far ahead of anything else in the UK, when "comics" meant The Beano (excellent though it was..) this, of course, was when the year 2000 was way in the future...

The movie came out in 95. The models for MegaCity 1 were in Lenox MA; I worked moving around motion control camera gear for them while I was in school. I loved the comic, even the later Dark Horse stuff.

Where are you located? Any pictures?

Did you look into ultrasonic welding? I know that this is used to make strong electrical connections between dissimilar metals and to secure some mechanical parts that might otherwise be damaged by high heat of brazing or welding.

The principal is similar to ultrasonic welding of plastics, only in metals the bond is more mechanical.

In plastics, application of ultrasonic energy causes friction which melts the surface, allowing the material to flow together in liquid form creating a true weld. The weld will remain isolated yet cool fairly quickly since the surrounding material stayed cool, as plastic is a poor conductor of heat.

In metals, the temperature is not raised high enough to melt the metal, but its ductility allows solid flow to fill the irregularities in the surface and form a mechanical joint or bond. I believe that is the theory, anyway.

We've used ultrasonic welding for seaming and joining polyethylene sheets, indeed, I believe that no satisfactory adhesive has yet been found. This was for a project to make covers for "poly-tunnel" hemicylindrical greenhouses, the welding serving to form water-pockets for tensioning and ballasting the clear plastic cover. The covering sheet is usually buried at the edges, but this gives uneven results, which means that the cover can start to "flog" in high winds, at which point it doesn't usually last long. It worked very well - some of the covers were good for three or four years, whereas we usually counted on replacing them yearly, if we were lucky. However, a homemade generator for 100 micron PE is not going to get far on 1.5" x 24" brass...

This idea, with several others, was never commercialised - I'm just not interested. Business people rarely if ever understand inventors, and these later often end up bitter and disillusioned. Let's hear it for the Public Domain! The Free (as in Liberty, not gratuity) Software movement should be an example to us all.