Doug,
I KNOW!  I've received some very painful shocks from 12VDC, and even from 5VDC!  You'd be amazed at the amperage on some of the spacecraft!  Thanks.
Not quite sure how to take that.
Doug

Doug,
I cut and pasted from a previous message:
I was an aerospace worker for twenty-two odd years, started on Voyager and ended up working on Endeavor.

These are NASA spacecraft that I was involved in the construction/assembly/quality control (HA!) of.

If that explains how to take that?

Rose is Rose

I just bought an old "Airco" welder/generator, almost an antique.  Gas engine, air cooled 2 cyclinder Kohler I think. Label KW rating is 10KW.
The recepticals are 110V AC two prong outlets and there is a 110V DC two prong outlet.  220 is accessable via a three lug connector, labeled 1, 2, 3    1 to 2=110v, 1 to 3 =220v, and 2 to 3=110v.  I plan to change out the two prong 110v outlets with three prong outlets.
I hope to ground the generator trailer frame to a copper ground stake, like my neighbor has his generator grounded.  He says I need at least 6 or 8 feet of rod driven into the ground, sounds right to me.
When I use the generator for my well pump I think the ground connector is not a concern, but when I use grounded tools or appliances on 110 volts AC, I understand the ground is extremely important.  Makes sense to me also.
I have some aerospace industry assembly experience, actually a lot, but the reason for this inquiry is that the engine starting-charging circuit is "positive ground" and I just cannot get my head around the idea of positive ground versus negative ground. 
The "silly little girl" in me is asking, am I looking at or for a problem that doesn't exist or am I just waking up at night out of boredom?

I am also watching for an 1800RPM diesel engine to install someday in the future when the gas engine dies.

Thanks all,
Rose is Rose

This has to be one of the hotest and coldest conversations I have ever tried to follow!
I see no issue with big business trying to get better deals, we all try to get the better end of the deal (at least, most of the time).
I think the problem is not just corporate greed but government sell out to big business!
Sure, we elected 'em Zeke and we can remove them - but I think we will see freeze warnings from the opening gates to the very center of hell first!

As Ross Perot used to say "I find it very interesting" that big oil claims lack of refinery capacity but has suddenly found that processing "normaly waste" products in the existing refineries will do ANYTHING to help the consumer in an way shape or form!  (Ross' saying in quotes only, not the entire sentence)

Why do dogs lick themselves? 'cause they can!
Low speed diesel engines........ Our glorious leaders have so graciously protected us from the evils of diesel engines - - - - -'cause they can!
They tax us nearly out of existance - 'cause they can!
There must NOT be a reasonably priced version of a low speed small diesel that meets our wonderful EPA requirements or we would be seeing advertisements for them!
Why are NO companies jumping on the low speed ci engine development and manufacturing bandwagon?
My reply here is not intended to hurt feelings nor to anger - just remember the truth sometimes hurts (and sometimes it hurts terribly!)
Vic

Vic,
It seems that you are or were a fan of Ross Perot.  I was very swayed by his first run at presidency.  It didn't take too long for me to realize that although he had a firm grip on the existance of problems, he seemed to have very little grasp on the possible solutions to the problems.
Having said that, what exactly are you trying to say in your message?

Rose is Rose

After much searching ( about 15 minuts worth in the bone yard ) I've decided I should make a fuel tank for Gus.
I assume he used a much higher tin alloy than I'm used to using. The Silver is no good ( at least the stuff I used in the motor shop too much heat needed ) so what kind of solder is right for joining a steel tank, and what kinf of acid flux is best. How big of an Iron do I need and or should I try electric or copper heated by torch ect...
Doug

Doug,
After many days of considering this question and answers, it looks to me like your questions were never really answered.  As I mentioned, my grandaddy was a tinsmith and he was a good one, he used a flame heated, large copper iron.  He used 67% tin-33% lead, cometimes called eutectic alloy.  He used sulphuric acid as a cleaner, and a paste flux which was an acid based flux and he used sal ammoniac as a tip cleaner for his soldering iron.  The iron was solid copper and might have weighed 2 or 3 pounds and it took a while to heat it but it really did the job.

Based on many posts I have read here, I think I will coin a phrase by saying "the GF way" is as listed above!  Not the only way, just the best way.

Rose on her motorcycle

Hmm. I've never really had any trouble with the "standard" 60/40 on tinplate/mild steel with a decent acid flux. That is, all the containers I've made have never leaked......
- 60/40 solder should do it. The triangular solder sticks about a foot long and 3/8" on each side are good for this kind of thing.
- You'll probably need a small gas torch, electric irons would be a little on the small side, unless you've got a 300-watter about the place. You can cook the solder with the gas torch, so use it to heat a seam and then sweat solder into it - just like 'normal' soldering it should flow into the seam nicely by itself. I've one that's basically a burner on top of a small disposable can, nothing special, throws maybe a 1" blue flame.
- I use "Bakers Soldering Fluid", acid based. Run it along the seam, sizzle it a bit with the torch. Don't breathe the fumes 

When I was doing this kind of thing many years ago, I used to make a "J" on the end of each piece of tin, hook them together and (gently!) hammer flat. You then solder the side that's accessible and the hammered-flat J makes a small recess to leave a nice bead of solder in. Putting the top and bottom halves of a tank on, I would probably form a lip (Kind of a sideways "S" shape) around the top of the lower piece, dished enough to hold a small amount of solder, make a matching lip on the top half, tin both parts with extra solder on the bottom part, place together, and sweat with the torch.

Hi Guy,
This is my first post (after my hello) and I can say my grandaddy was a tinsmith.  I went with him many times in the early 50's as he built sheetmetal structures and parts.
He used a bar of solder about 3/4" wide by about 1/2" thick.  Maybe 12-16 inches long, seems like the solder bar was stamped "60/40".  Not really sure from more than 50 years ago.  He used a small furnace resembeling a coffee can burning charcoal that looked like burnt wood, not briquets.  He placed a large "iron" maybe 2"x2"x6" made of copper with a handle around 24" long into the "furnace" and then used the iron to heat the metal before touching it with the solder.  The solder always flowed into the joint like grease in a skillet.  Sometimes when he was in a hurry he would heat the iron with a blowtorch, a pump up white gas fueled torch to heat the soldering iron.
I asked him "why not just use the torch to heat the metal?" and he said "silly girl, the torch will just warp the metal!"  Of course, the metal was always copper or very light weight galvanized or tin metal so this might not apply in your application.

Rose is Rose