Saturday, June 3, 2017

Touching hot electrodes

Touching hot electrodes with bare fingers is not to be recommended! After I'd ground the edges of my welded contraption down to be significantly less blobby, I was left with plenty holes in my seams. That meant filling them was in order. Thus my first idea was to dribble molten solder into the holes. Thus I got some high tin solder to use with my butane torch. Well, the first attempt didn't work. The solder went into nice little balls and rolled away.

As an interesting aside, the towers of Tower bridge in London are 40 feet high and are not primarily there for the bridge. They're actually shot towers back from the days when lead was melted and swung around in a big frying pan with holes drilled in the bottom. As the lead went through the holes, it would form a ball as it fell. It would take 40 feet of falling before it would be cool enough to catch in a tank of water below to harvest as ball ammunition for rifles and pistols. Being cast this way meant there would be no mold marks and the balls would be perfect.

The second attempt was a patch. I'd read about somebody filling a space with an oversized welding rod and welding that into place. I tried a compromise of soldering it using solder and my butane torch. Well, that didn't work either and unthinkingly afterwards, I picked the rod up to discard it. Ouch! It was still hot! Thus I burned not just my finger but a very sensitive area of my finger so now my arm feels like it's on fire - even though I immediately pressed a lump of ice on the burn to bring the temperature down. Putting ice and holding it there for at least 5 minutes stops internal burning from continuing and reduces the burn. I still have a painful mark that'll take a while to vanish though!
After that I went back to welding rods and my old method. This results in very pixelated welds. I drag the rod quickly over the hole repeatedly until enough deposit builds up to fill the hole. Leave the rod for a hair longer results in the surrounding steel burning away in a shower of sparks. Having filled the holes, the next task is to attack the holes from the other side. Now the steel is built up, its possible to let the rod linger a while longer to build up body. Needless to say, today I'm not having too much difficulty in starting and maintains an arc!

I'd finished filling holes from both sides using a 1/16 6011 welding rod when I began to hear spots of rain. By the time I'd packed up and put everything away, it was raining quite well. That was the end of the days work, sadly. Sure, there's other stuff that needs doing, particularly completing redoing the under cabinet wiring. That can wait though until the galley floor is clear enough to lie on.

There are still two pinholes in my welded seams but by the time the whole thing has had antitrust primer and white paint, they'll be filled. Then I'll run some latex seal around all the inside angles. That'll make the whole thing good and airtight. The next stage is though to clean flush, the mounting surface for the as yet to be constructed top of the unit and to extend the mounting flanges I welded on a week or so back. That will allow me to bolt the top on using a pair of 1/4 inch bolts.

Anything thing to be done before putting the top together is to weld wide mounting flanges on the sides of my box. I have angle bracket for that but it'll need to be cut severely. I'll also have to make a door that'll press my air filter nicely into place. I'm still thinking on the design for that one!

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