[Vwdiesel] Broken Bleeder Valves
jhsg at sk.sympatico.ca
Wed Mar 12 00:59:47 EST 2003
Just a couple things to add to a well written article.
Buy as much welder as you can afford.
The really cheap wire feed welders, are poor at best. stick with a brand
name, buy a good mig with gas, and you will have no need for anything else
to weld with. Brand names like Lincoln, Hobart, Esab, Panasonic, Miller are
good ones to stick with, I've used or demo'ed them all, and they work very
well. I've helped friends to get their no name on sale welders going, and I
can barely make a bead with them, let alone get them to work for a newbie to
mig welding. Pay some attention to duty cycle, the small ones are only good
for about a 10% duty cycle, meaning they run for a minute, they need nine
more to cool the transformer at some point. Wire feed is in two flavors-
flux core, or gas sheild. Gas works well indoors, but if you weld outdoors,
you need the flux core as the sheild gas doesn't blow away as easily. You
get a mig, forget about burning sticks. My 300 amp hobart gas welder might
as well be sold, I use it only on mobile repairs now, like once a year and
the shop ac/dc hasn't been turned on in a year at least. I used to burn a
hundred pounds of rod a year in the shop minimum. now I just go through a
few 20 lb spools of wire, and the welds are better and stronger.
On to gas welding
Oxy acetylene is okay, but expensive to have. Most of the time there is a
contract for tank rental, but the contract cost is mostly for insurance-
part of the cost of ownership is the exorbitant amounts of premium money
that the insurance companies want to insure your shop if you own your own
tanks. Contracts take care of that, but are costly too. Liability issues
on owning acetylene tanks in your home are large. Oxygen is not an issue.
There is no real replacement for learning to gas weld on oxy acetylene. The
skills are transferable to most forms of welding from tig to mig to stick.
Take a community college course, and I would think they still may teach gas
welding as a first step. It's a good thing to learn.
For precision mild steel welds, acetylene is the absolute best next to tig.
You can't gas weld with propane worth beans, but who cares, if you have a
mig, you will never need to. I used to burn up three tanks of acetylene a
year, as all small stuff was gas welded, and arc for the big stuff. Now
with a mig, I use a tank every two years. I will be getting propane when my
contract runs out next time. I've used propane, and it actually seems to
cut easier. You can buy dedicated propane torches, and they are very nice.
Another advantage with propane is the oxygen tank is cheaper to own as well,
less dangerous, cheaper to insure.
Stitch welders are just a mig that has a timer function that enables you to
hold the stinger at the correct distance, and hold the trigger on. The
timer starts and stops the welder just as if you were stitch welding with
pulling the trigger and releasing it. I don't really like them, my finger
moves and pulls the trigger just fine, maybe if you did nothing but weld
thin body metal all day, it would be nice. The idea here is to get enough
heat to get a full penetration weld, but stop before you blow a hole, allows
things to cool, then restart.
Compressor. Get as big a tank as you have room for, it will help with the
air tool usage by providing reserve.
> -----Original Message-----
> From: vwdiesel-admin at vwfans.com [mailto:vwdiesel-admin at vwfans.com]On
> Behalf Of Lee Hillsgrove
> Sent: Tuesday, March 11, 2003 10:14 PM
> To: vwdiesel at vwfans.com
> Subject: Re: [Vwdiesel] Broken Bleeder Valves
> >I've always wanted to get a small tank oxy-acetylene
> >torch for home use, but w/ a full size burner head. In
> >shops I've seen ones w/ tanks about two feet tall.
> >Where can these be bought? Used appeals to me for
> >price reasons. What attachments are needed? Also, are
> >these jsut for cutting metal and heating up stuff real
> >hot, or can you weld with these? I'd also like an ark
> >welder for true welding. Oh, and I guess an air
> >compressor and air tools would do nicely too.
> Oxy-acetylene torches are great - nothing beats a red wrench!
> The problem with small acetylene tanks is that they aren't rated for a
> great amount of flow, probably not enough to support a large heating tip.
> Acetylene is pretty unstable stuff that can self-ignite from the
> friction of
> flowing through hoses at gas pressures over 15 psi. How do they fill the
> tanks to the high pressure which they contain without an
> explosion, you ask?
> The tanks that contain it are specially constructed with a stone or
> spongelike filler, loaded with liquid acetone. The acetone bonds with the
> acetylene gas to make it less sensitive. The gas can be forced into or
> dissolved from the acetone at a set rate of flow, if you try to
> extract more
> gas from a tank than it is rated for then you run the risk of drawing
> acetone out along with the acetylene. Acetone is harmful to the
> rubber torch
> hoses, so this is not a good situation. You can tell if you are burning
> acetone by the presence of purple in the flame. If you want to
> run something
> like a rosebud tip without overdrawing your tank, you'll need to connect
> multiple tanks with a manifold to make up the cfm. Acetylene
> tanks must also
> be stored and used in an upright position. If they have been laying down
> you're supposed to leave them upright for a while before using any gas.
> You must also respect high pressure oxygen tanks. If one falls
> over because
> it was not properly chained to the wall and knocks the valve off the top,
> bad things WILL happen. These tanks have been known to pass through entire
> buildings, blowing through concrete walls, and keep on going. Range of a
> full tank is in excess of 3 miles.
> A decent substitute for acetylene is propane. It's cheap and
> plentiful when
> compared to acetylene, and contains almost as much energy
> content. The tanks
> can be bought and refilled practically anywhere, but you do need to use
> different torch tips which have bigger orifices in order to make
> up for the
> reduced Btu content.
> Some plumbing shops use torches that burn propane, acetylene, or Mapp gas
> combined with atmospheric air. They get pretty hot but are not as
> good as an
> oxy-fuel setup.
> Not sure where you could get a torch set used, but eBay springs
> to mind. I
> think most places will only lease the larger tanks now, not sell them. My
> dad bought two sets of O2 and acetylene tanks and has the slips
> to prove it,
> we always have to bring the paperwork when it's time to refill the tanks
> since they don't believe that anyone owns their own tanks anymore
> and they'd
> prefer not to honor his ownership. Just the torch set shouldn't
> be too hard
> to find, though. Try and look for a propane setup since that way
> you'll only
> have to lease the O2 tank. If you don't use your torch a lot the
> lease cost
> per year on the tanks can easily be more than the cost of the gas. We
> usually use one tank of fuel to two tanks of oxygen.
> A complete torch set would consist of a set of hoses with flame
> regulators, handle with gas valves, and an assortment of different sized
> tips, along with a cutting torch attachment. You might also find
> a striker,
> goggles or a face shield, and a set of torch cleaners in there as well.
> Victor makes a nice set in a blow-molded plastic case.
> You can indeed weld with a gas flame. That's what they taught us to do
> first in metal shop. (Of course I was already arc welding with dad's
> equipment at home by that point, but...) Gas welding is pretty fun and can
> do a very nice job. The thickness you would be capable of welding
> depends on
> the amount of heat available. You can also use a torch to braze and solder
> pipes with appropriately sized tips.
> What you would want for a welder depends on what you'll be
> welding and how
> much $ you want to spend. Price ranges from less than $100 for a 110V
> buzz-box AC stick welder to well into the thousands for a Tig
> welder. I have
> at home a 110V Lincoln wire-feed Mig welder which uses flux-core
> wire, so no
> shielding gas is required. It does a decent job on metal up to about 1/4"
> thick and will do 3/8" if you are patient and willing to do
> multiple passes.
> You do need a dedicated 20A circuit if you are going to be running at or
> near full power. I have successfully welded the sheet metal on
> the inside of
> the door of a Toyota pickup I had, and you can imagine how thin that stuff
> was. I couldn't run a continuous bead, though, or it would burn
> through. If
> you're going to be doing a lot of body work, the solid wire and shielding
> gas is the way to go. Small tanks like the size you'd use are able to be
> purchased, but you still need to get them filled with Argon or a mix of
> shielding gas at a welding supply or industrial gas store. This welder was
> somewhere around $350, I think, and the gas kit runs another $150 or so, I
> haven't kept current on the prices. You can get this welder in Harbor
> Freight or Home Depot last I knew.
> I also have a very large AC arc welder which was given to me. It runs on
> 240 or 480V single phase and is capable of 600 amps output if fed with
> enough input current. It's not the best choice for welding sheet metal....
> Air compressors are pretty easy to scope out, I see them all the time.
> Places like Wal-Mart or auto parts stores sell smaller capacity
> ones, while
> I've seen some pretty big ones in Home Depot. Buy the most cfm you can
> afford if you're going to be using air tools.
> Did I miss anything?
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