How many times have you said: "Dang, I wish I would have bought the cheap tool instead!"
There are lots of ways to weld.
Here are what you might call the "big 4":
Superior Steel is a bigger place, and the only place to get big pieces of plate and things of that sort. They sometimes have "cutoff" pieces they will sell to a small buyer like myself. I called in June of 2010 to ask a price of an item on their website (a roll of remesh) and was told they don't sell it and haven't carried it for at least 10 years, so that is something to bear in mind.
10 gauge 0.1345 inches 9/64 90 oz/sf 12 gauge 0.1046 inches 7/64 70 oz/sf 14 gauge 0.0747 inches 5/64 50 oz/sf 16 gauge 0.0598 inches 1/16 40 oz/sf 18 gauge 0.0478 inches 1/20 32 oz/sf (2 pounds per sq. foot) 22 gauge 0.0312 inches 1/32 20 oz/sfNote that anything 1/4 inch or thicker is called "plate" not "sheet". The metal gauge system is intended to make weight calculations easier, though the details have yet to be described to me clearly. Steel weights 41.82 pounds per square foot per inch thick.
Here are some interesting links:
Someday, I would like to own a 110 volt MIG welder.
MIG (metal inert gas) is kind of a slang abbreviation for GMAW.
The big names are Miller, Lincoln, and Hobart.
You can find all kinds of opinions on which is best,
but it is seems to be a Chevy versus Ford thing.
Although I am probably going to buy a 110 volt unit like the Miller 140, I recognize the virtues of having a 220 volt unit (like the miller 180, or Hobar Handler 187), but the convenience of the 110 unit (it does need a 20 amp dedicated circuit) carries the day for me. It means that I can throw it in the truck and go help out a buddy who doesn't have a special circuit for it. It will also do everything that I want to do with it at this point in time. Pushed to the limit, a 110 volt welder can weld 1/4 or even 5/16 metal. Flux core wire instead of gas is recommended to increase heat and penetration. You will need to go slow. A 220 volt unit will do these big jobs smoothly and with ease.
The cheap welders at places like Harbor-Freight may be wire-feed, but are not MIG.
They are designed for flux core wire only, which is fine for many jobs.
Caveat emptor.
TIG welders are capable of amazing things, but are priced far out of reach of most people.
A "buzz-box" stick welding rig could be an inexpensive solution for someone who wanted to weld some heavier material. This might be a place where a cheap Harbor-freight unit could be considered, but I bet that you would ultimately regret it. There are things to buy at Harbor-Freight, but I don't think power tools and welders are among them.
A torch set (oxygen and acetylene bottles) allows many more things to be done. You can cut heavy steel with the torch, and braze delicate materials. Remember that oxyacetylene gave birth to other forms of welding, certified airframes can be built using oxyacetylene gear.
Here are some words from a post by Brian Martin on www.hotrodders.com
The MIG is used in EVERY SINGLE auto manufacturers welding reqirements for sheetmetal. It is used in EVERY SINGLE welding requirements set by nationally known orgianizations such as ICAR and ASE. It is THE standard of the autobody industry. It is not only the "standard" it is the ONLY welder seen. TIG isn't even mentioned, gas torch isn't even mentioned for welding sheetmetal.On which "cheap welder", A Miller 130 135 or 140 is a FINE 110V welder and will set you back about 800 bucks with the gas tank and all. In my opinion, it is as cheap as I am going to get. Anything cheaper than that (new) is just not worth spending the money on. As for the gas bottle: My suggestion is to buy the biggest one you have room for. DON'T CHEAP OUT and buy a little bottle thinking you don't use it much bla bla bla. A small bottle STOPS your progress and just plain wastes time. I bought small bottles for my torch, STUPID, I now have to go get larger ones. My MIG has an 100 CF or something like that on it. It will last literally a year or more. THAT is what I am talking about baby, work instead of going to fill bottles.
Now I have never used this exact welder, the 140. But I assume by reading the description that it is simply a 140 amp version of the 130 and 135 welders that we have at work. We have about 8 of them. This is at a shop with a bunch of guys using them. If you have ever seen what "shop tools" look like around the average bodyshop you would understand that these welders are some tough buggers to last in this environment. They work day after day, week after week year after year without so much as a whimper. We replace a gun now and then, or switches in the gun, THAT is it, PERIOD. We fill the tanks and put wire in them along with the contact tip and use them day after day, they are TOUGH little welders.
We weld light frames even with them. They are certainly big enough for EVERY SINGLE COMPONANT on a unibody car or ANY car or truck body.
If you are going to be welding sheet metal 99% of the time, this is the welder for you. For that 1% where you need a 200 amp 220v welder, rent it or borrow it. There is no need to buy a 220V. If you plan on welding up a frame or something for your rod, get a 220v you will be glad you did. Plan on spending about three or four hundred bucks more.
There is some commonly heard (but erroneous) story that Miller owns Hobart. This is not true. Both Miller and Hobart are owned by a parent company ITW (Illinois Tool Works), but they are different plants in different locations. Thinking of Hobart as Millers low end line is wrong, although they are aimed at somewhat different markets. Millers are aimed at a commercial market, and tend to be a bit more "high end" than the Hobarts, but both are fine machines.
The business of buying "used" tanks is a true snake pit. Many tanks are in truth leased, which means that they are owned by the company leasing them and cannot be sold to someone else. If you did buy such tanks (which typically are marked by the companies name stamped into the metal) and try to get them filled, they quite likely would be confiscated.
Beware of rules about getting bottles refilled, which vary from state to state and from company to company.
If the bottles have no such marks, they are your property and in Arizona at least, any company will fill them (in truth they will swap them for a full bottle). In theory you are responsible to keep them in hydro and fix problems with the valves, but since you are exchanging them, this is not an issue, unless you don't use it for a long time and it requires a hydro inspection. This will cost you an extra $25 or so.
Here are some more details about figuring out whether you want to buy a used set of bottles. Carefully inspect the neck ring and the area on the bottle near the neck. If they are marked "property of acme welding supply", do not buy them. If it is a company you have never heard of, just call your local welding supply place and ask them. For example, "Union Carbide" is found on some tanks, but they are no longer in the welding gas business and such a tank could be owned by an individual.
Also look at the ICC number. A bottle will typically have a marking like:
DOT 3AA 2265The number 2265 indicates that the tank is rated for 2265 PSI, i.e. it is a pressure rating, but it turns out that the shops in my area use this as a guide to identify leased tanks. Apparently most 2265 and 2400 psi rated large tanks are leased tanks (but not all). These will typically also have ownership markings.
The other issue with bottles is the "hydro test". Bottles must be tested and certified every 5 or 10 years and are stamped with the month and year of each test. If the digits for the year are followed by a star (or a box), the test is good for 10 years; if not, it is good for 5 years, so:
Rumor has it that the B size acetylene tank gets the "B" for bus, and the MC size acetylene tanks gets the "MC" for motorcycle, and this dates back to when they used the gas for headlights. The following data also applies, but I have had only limited success reconciling it with the above graphics. Apparently MC holds 10CF and B holds 40CF.
R - 20 CF - 5.3125" O.D. - 19" tall AXL - 55 CF - 41 tall Q - 80 CF- 7.125" O.D. - 35" tall XL - 70 CF - 6" O.D. - 41" tall D - 122 CF - 7.5" O.D. - 48" tall E or Y - 122 CF - 7.0" O.D. - 48" tall S - 150 CF - 7.375" O.D.- 51" tall LK - 244 CF- 8.9375" O.D. - 56" tall K or KL - 244 CF - 9.00" O.D. - 56" tall T - 330 CF - 9.25" O.D. - 60" tall
MC - 10 CF - 4" O.D. - 14" tall B - 40 CF - 6.25" O.D. - 23" tall WQ - 60 CF - 7.625" O.D. - 24.25" tall WC - 111 CF - 8.5" O.D. - 37.5" tall WS - 130 CF - 8.5" O.D. - 35.5" tall WSL - 130 CF - 8.5" O.D. - 33.5" tall WK - 304 CF - 12-.875" O.D. - 42" tall WTL - 390 CF - 12.5" O.D. - 44.375" tall
Never use the bottle with it on its side, as this may force acetone into the hoses and torch. Also, never allow acetylene pressures above 15 psi. Gaseous acetylene at pressures over 15 psi will begin to dissasociate, yielding heat and possible explosion. Having a fire extinguisher handy is a fine idea.
Acetylene tanks have fusible plugs designed to melt and release pressure at temperatures over 212 F.
Also if you draw acetylene at too fast a rate, the bottle can overheat and explode. The first rule of thumb I heard for this was 1/7 of the bottle capacity per hour. Obviously this is a big issue with small bottles. More recently I heard the recommendation of limiting the withdrawal rate to 1/10 of the cylinder capacity per hour in intermittent use and 1/15 of the cylinder capacity per hour in continuous use.
With my tiny "MC"bottle (10 CF capacity), drawing over 1 CF per hour would be hazardous (i.e. any use that drains the bottle in less than 10 hours would be inadvisable). What this means is that any use other than a few minutes use here and there would not be a good idea. Here are some other related facts, with the bottle recommendations based on the 1/7 rule:
I have a little portable brazing/welding rig. As near as I can tell it has an MC size (10CF) acetylene bottle (8.5 pounds) along with a 20CF oxygen bottle (13 pounds). A good match given that you typically use oxygen at twice the rate as acetylene. And the pair of botles weighs 21.5 pounds, very portable.
To upgrade my 10CF acetylene bottle to a 40CF (size B) acetylene bottle would cost me $56.39 (in early 2010), but I might find that the valve thread size changes and I would then need an adapter. This bottle weighs 25.5 pounds.
To upgrade my 20CF oxygen bottle to a 55 CF size would cost me $87.20. The next size (80CF) would be more suitable (having twice the volume as the acetylene bottle it is paired with), but would also weigh 53 pounds instead of 25 pounds.
The size 40CF acetylene paired with the 55 CF oxygen would weigh 50.5 pounds.
Uncle Tom's Welding pages / tom@mmto.org