So here's a small update on the stuff i'm trying to do, some 'input from people who know what they're doing' is very much appreciated

I want to mount my alternator low on my b230ft, so i did some research and it looks like the only way to do this is to make a custom bracket. so i found some inspiration and about 2 days later i have this:



She's rough Jim.

So i found out that my welder really does not like 3/16" steel. I sort of beveled the edges on the later pieces and got some better penetration. Looks rather ugly, but it appears to be strong? i'll probably grind them down once more and go over them with a real welder.

Any suggestions on how to stress test this piece before i run it in the car?

The other thing i've got is a 2.5" v-band flange to replace my loathesome conical flange.
The cost difference getting a 3" vband housing was prohibitive, so i decided i'd opt for transitioning the downpipe 2.5" straight up to 3" right after the flange.



I notice there's a rather large lip here...



There appears to be a lot of metal behind it, could i get away with grinding that ridge flat? i'd gain about 8mm on the overall diameter which would make me happy.

Your weld looks cold to me...crank up the heat. Stick the wire into the weld puddle and get it done. Welds without penetration may look strong but will crack very easily as they have no real bond. Stress test as follows, replicate one of your joints (say that fillet that has the cold weld) - take it to a vice, clamp, hit with hammer. If it bends but doesn't break, you're good. If it breaks, do it until it doesn't.

I did the ol' whack it with a hammer trick...it 'passed', but i'm still unconvinced.

I think you know that it should be taken in somewhere and welded up nicely. If you were more local, I'd make it pretty for you.

Not clear from the picture -- did you grind off the scale down to bare metal before welding? MIG and TIG like clean metal.

RT

Well, MIG doesn't really care much, but TIG sure doesn't like that scale. Some 6013 and a reasonable power source would work well for metal prep'd this way! I'm not trying to be a jerk, I just sound that way on the internet.

Yep. Ground down to bare metal, welder set up for maximum amperage, slowest wire speed. This is the thickest metal Ive ever attempted to weld with this 110 mig. I thought it could do up to 1/4", turns out I'm mistaken.

I had the thought that perhaps my grounding clamp wasn't making good contact to deliver the max amperage...I'll go check that.

In the mean time I've had a few friends with real welders offer to go over it for me

Max amps and more wire feed...not less.

Hmm, more speed? really?

Yea so, tried a few things with no success. i ended up grinding the welds down and finding almost no penetration with the metal

Going to take it to a buddy's place with a better welder and hopefully get some better results.

Basic MIG theory:

1. MIG (or GMAW) is based on a constant voltage (that's the "heat" dial) and a consumable wire electrode (wire feed dial - if fancy, it's in inches per minute - this controls both wire feed and current (amperage)).

2. The shielding gas only performs a shielding and cleaning function - this is fundamentally different from say TIG welding. It keeps the molten weld pool in a different atmosphere while the weld is forming and during initial solidification. Set it and forget it.

3. Material thickness controls amperage for all weld processes (that involve electricity) and for GMAW, 1 amp per thou of thickness is a general rule for steel.

4. Wire is consumed at a rate that is proportional to the wire size, amps and the voltage applied. For example, if your welding sheet metal, I'll assume you're using either 0.030" or 0.035" wire. The guidelines indicate that for 0.030" wire, the wire feed rate should be 2" per minute per amp of current. So the "heat" dial sets the voltage (think depth of penetration - voltage is a force) and the wire feed controls the rate of wire consumption (current or rate). That's how they compute the charts on the inside of your machine that tell you the settings for a given gauge by a wire diameter.

5. The length of the arc that you maintain controls the current...this gets a little tricky, so let me try to explain it this way. All of what I've said so far makes sense (voltage, wire feed, amps) if and only if the length of the arc is a constant. If you need to "cool off" your weld, lengthen your arc or to heat it up, tighten the distance. One of the mistakes I see with beginners is holding the MIG gun so that they can see the weld and therefore holding the arc a long way off the weld. Push that sucker down into the puddle. This is what's called "Stick Out" which refers to the distance from the electrode being consumed to the weld puddle. A normal arc length is around 1/4".

For practice, I suggest you do the following:

1. Grab some scrap material (1/8" flat bar) and set the voltage and wire feed based on the guidelines with your machine (I'm assuming you're gas is set properly). Then hold the gun with both hands and set a distance 1/4" off the target (get a feel for that distance by setting your tip on a few pieces of scrap that make up that height). Now move off your support, and with your helmet down, pull the trigger and move (push/pull...I don't care) and see what happens when you hold the gun straight down. Now you'll need a bit of angle, so try 10-15° and go again. Adjust only the wire feed knob until you get the wire melting but not bumping into the puddle and not melting back into the tip. It should sound like frying bacon...now you're cookin (sorry - couldn't resist).

2. Go weld - you're now a pro.

Craig

http://www.millerwelds.com/pdf/mig_handbook.pdf

I split Craig's reply off this thread and started a new thread called "Craig's Welding Thread".

We'll try and keep Craig's Welding Thread clean and full of information, and only post general welding-related questions and info there. Keep the specifics to this thread here. Keep discussing this particular issue, but I ask all the real welders to keep updating the welding thread with little nuggets of information that we can all use.

ohh great. I'd hate to threadjack the welding thread with off-topic questions about my engine build


(no updates yet, haven't had time to work on my hoopty for a few days)

Ok so, got the cottage cheese welds redone by my buddy who's got a real welder.
I think my issue might've been proper grounding. My bud used his angle grinder to take the skin off not like the brush wheel I was using. Seemed to make a helluva better weld, and some good penetration. Have a little warpage to deal with but the two brackets should still be in alignment (we threaded a bolt through to keep it straight)

That'll hold...grind them pretty, paint and you're good.