As I have been going through some old posts I have seen a fair amount of discussion on how to weld,what machine to buy etc. As a certified welder I can tell you a few things right off the bat. if you are only going to be using it for sheet metal and light steel ( up to 3/8 ) you don't need any more then a 150 amp machine. Go mig, it is the easiest, fastest and cheapest, I know tig is THE thing now, but it isn't for sheet metal due to machine cost, material cost, learning curve and if you don't know what you are doing you can warp the hell out of a panel tigging. .023 wire is all you will need, anything larger will require more amperage and will burn through. Don't mess with flux core on sheet metal, you will most likely ruin your job. My first machine was a 250 amp and came with .035 wire and I used it for panel replacement succesfully, but not without a lot of patience. When I finally broke down and bought the neccessary parts to run .023, my job time was cut almost in half because I didn't have to give the panel as much time to cool.Spot weld across the panel not around ( noth, south, east, west, repeat ) until you have enough strenth to run small stringers, then do that in a simmilar pattern. Two pieces of angle, c-clamps, a rubber malet and a body hammer make a great brake, I made several pieces, including entry steps like this before buying a brake. Always remember, if you can see 2" of rust ......there will be 5"!!!

Thanks Scotty, great timing as I'm about to start welding on my car for the first time.

Sean

thanks scotty!! i'm looking forward to getting into welding. it's always nice to get some
tips from a pro. how about welding stainless to regular steel? any good tips? i have a stainless muffler that i'd like to put on my teener, but i need to weld on a hanger or something to secure it.

Hi Scotty,

Mig may be fastest, cheapest, easiest..just not best, and maybe not cheapest...you can get a good oxy-acetylene setup pretty cheap used, since so many are going to mig or tig.

Mig is fine for general all around work on a car including the thicker structural stuff, but gas-welding wins if you want to do the best sheet metal work possible with no filler, or very little at the most.

Mig is the easiest to learn, but it makes for a hard time metal-finishing..even after grinding the weld, hammer and dolly work is more difficult..gas-welds do not have to be ground before using a hammer and dolly. As a test, cut through a mig weld, then a gas weld with aviation snips... a big difference. The mig-weld acts like a stiffener, the gas-weld is just like the parent metal.

You can weld longish sections with a torch and still get the shape back fairly easily...welding anything more than a hot tack at a time with mig on sheet metal in one go is asking for severe shrinkage that is difficult to get out.

I only mention this because there is a popular myth that mig is better, when it actually has only some advantages, with disadvantages as well. It is probably the best choice for a home hobbiest. Welcome to the 914 club!

John www.ghiaspecialties.com

Good point on the gas John, I just feel like the learning curve for gas is almost as bad as tig even though gas is far more forgiving; and then there is the open flame which can be scary and dangerous for a novice. I definitly heed to you, I am also a member of MSA and have seen your work!! By the way are you still offering the flare video?, and is it on dvd by chance??? One other thing for the beginners, get your metal CLEAN and DO NOT weld over galvanizing, if you don't know if it is you wil as soon as you start to weld. Fumes are very bad and stink, also look for smoke and yellowish residue around weld.

QUOTE

.you can get a good oxy-acetylene setup pretty cheap used, since so many are going to mig or tig.

yep.......I'm trying to talk a co-worker into selling his oxy-acet. setup and his TIG welder to me...I figure it would be a win-win since he' cut me a great price and I'd let him have access to them whenever he wants.....my MIG can only do so much and I do miss what can be done with a gas rig

I have both MIG and Oxy-Acetylene welders.

With thin gauge steel, like autobody panels, using a MIG welder with .023 wire is a lot easier and faster. But, like John Kelly (no relation) says - the metal finishing is a lot harder.

When buying a gas welding outfit for sheet metal work try to get the smallest flow oxygen regulator you can. You only need about 2-4 psi of oxygen to do most jobs. Most oxy-acetylene welding kits come with oxygen regulators having a 5-125 psi range. You can get oxygen regulators with a range of 0 - 30, which makes it a lot easier to adjust your torch to 2-4 psi. (Note: Acetylene regulators only come in one size, and you should never flow more than 15 psi of Acetylene.)

Also, try to get a aviation size torch handle and tips like a Meco Midget. They are smaller and lighter than the normal size, which makes it easier to handle.

Kevin.

QUOTE

Two pieces of angle, c-clamps, a rubber malet and a body hammer make a great brake, I made several pieces, including entry steps like this before buying a brake.

Can you translate that into Sanscrit so it will make more sense?

I'm a newbie welder. Bought a 110V mig. I could get decent welds on mild 18g if the surface was horizontal. But if verticle the puddle would would trickle away. Dont even want to think about welding overhead. Is verticle welding any easier with oxy/acetlyene?

I was also wondering if preheating an area with a propane torch would get better penetration and make faster and easier mig welds, especially if it is cold out. (Sorry if thats a rediculous question)

Bryan, anytime you are welding on sheet metal you want to start out with spot welds not run a stringer. Try short burts on vert surfaces, working across the panel, I tell people north,south,east,west repeat, trying to run stringers will only warp the metal or worse burn through. If you are having the weld drip you are most likely moving to slow which is depositing to much material and overheating the metal.The faster you try and weld, the bigger the mess you will make, there is not need to preheat sheet metal. fans

QUOTE (scotty b @ Jan 9 2005, 06:09 AM)

Good point on the gas John, I just feel like the learning curve for gas is almost as bad as tig even though gas is far more forgiving; and then there is the open flame which can be scary and dangerous for a novice. I definitly heed to you, I am also a member of MSA and have seen your work!! By the way are you still offering the flare video?, and is it on dvd by chance??? One other thing for the beginners, get your metal CLEAN and DO NOT weld over galvanizing, if you don't know if it is you wil as soon as you start to weld. Fumes are very bad and stink, also look for smoke and yellowish residue around weld.

Hi Scotty,

The flare video is in the final stages. I'm sending out the 90% done rough cut to a test audience of one (a 914club guy) to see how it is to someone who has not seen it a hundred times like I have. It will be on DVD only...at least to start. DVD players are so cheap (got one for $30) I'll probably just stay with them and not do VHS at all to keep costs down. It has a been a long tedious, but rewarding process. With any luck I'll be done by the end of the month.

BRP914,

Verticle welds are a little tough. For something non-structural, try downhand with a mig. For uphand welding, you can do a slight wash side to side as you go up which helps build a little shelf for the puddle to hang onto, also helps to point the gun up a little bit. This works better on an inside corner than a butt weld......or simply weld a very hot small weld...trigger off, move up a little, and weld again.

John www.ghiaspecialties.com

I'm a newbe, been lurking in the backround for several months now. These threads on welding have been very interesting but one thing has not been mentioned to the beginning welder. I hope that they all understand that to weld verticle in the GMAW (mig) process, they need to have a downward travel direction. You never weld verticle up. Verticle down is the easiest position to weld GMAW . Most pro's will position their work to allow welding in this position.
I am a CWI (certified welding inspector ) and an apprentice instructor. I always raise the bar on how the weld should look when my apprentices get into the verticle position.
Also remember that when welding verticle down the welder needs to increase heat (wire speed and volts) and travel speed by about 10%. The welder should also have about 3/8" stick out (end of wire to contact tip).

Hope this helps
Tim

I am definitly interested in the video John. Let me know when it is done and how much$

QUOTE (tsbcm @ Jan 10 2005, 04:54 AM)

I'm a newbe, been lurking in the backround for several months now. These threads on welding have been very interesting but one thing has not been mentioned to the beginning welder. I hope that they all understand that to weld verticle in the GMAW (mig) process, they need to have a downward travel direction. You never weld verticle up. Verticle down is the easiest position to weld GMAW . Most pro's will position their work to allow welding in this position. I am a CWI (certified welding inspector ) and an apprentice instructor. I always raise the bar on how the weld should look when my apprentices get into the verticle position. Also remember that when welding verticle down the welder needs to increase heat (wire speed and volts) and travel speed by about 10%. The welder should also have about 3/8" stick out (end of wire to contact tip). Hope this helps Tim

Hi Tim,

I've done plenty of verticle uphand with mig on heavier materials. I find it similar to verticle stick welding. Is there a reason you say not to, other than the fact that downhand is much easier?

Scotty,

Please email me directly to get on my list for the video: ghiafab@msn.com Thanks for your interest!

John www.ghiaspecialties.com

John
I should have clarified myself a little better. Verticle down is best when welding material less than 1/4" in thickness (most welding on 914's). This is due to the travel angle of the wire electrode. Welding down you "pull" the gun down the weld (electrode travel angle pointing up into the weld), this puts less heat into the material and with that comes less penetration. On material 1/4" and over, just as you stated, you weld verticle up with the gun pointing up into the weld, putting more heat into the weld. With the heavier material the welder will probable have to add a "weave" or side to side motion into the uphand travel, just as in SMAW (stick) welding.


Hope I didn't confuse anyone
Tim

Thanks for the clarification Tim!

John www.ghiaspecialties.com