body work for a newbie

[cantankrs]

Hi Michael,

I agree with Matthew except I gave up on the weld spot timer as I could wing it with less hassle. And hrpearce's bigger gap sounds right too. I've just checked what controls your Mig has in your earlier pic and I see your wirefeed was at that time set higher than your voltage. At those settings I normally would be doing continuous welds. If your welder dials do equate to mine (different brand) then for tacking I set the wirefeed rate just below the voltage rate (took me ages to work this out !@#$%^&)!! So set on '4' for voltage and just below 4 for wirefeed for single spot tacks. That has the heat high and the wirefeed slow to really fuse the tack with low buildup and maybe a little bulge on the back - but no gap still remaining at that spot. If you see gap still at the back then you're being too gentle and you have to find a closer compromise between tacking and melting through. If you're grinding flush (maybe you're removing a little too much I think and concaving the panel which means more body filler or spray putty) then in my opinion you want the back of your welds to be slightly bulged to provide strength. For thin stuff I never continuous welded longer than about 3/8" or I'd burn thru, or not penetrate, so good spotting was the go. And tacking at opposite places like tightening wheel nuts helps you keep progressing without stopping all the time to cool it (by force or naturally) - subject to patch size like Matthew says.

Also you might be able to squeeze a slight improvement (cos your pics are great) for us out of your pics if you wirebrush the soot off first. Would make it slightly easier to see and compare the tacks.

Regards

Alex

[Bob Carriere]

Nice job Stuart....... have you tried a copper backing plate to save on the grinding....?

Same process using the clamps but get a piece of copper from the scrap yard..... the heavier the better.... I have some 1/4 inch printing plates..... 3 by 7 from Cohen..... about $3.00 a pound..... brass blocks are also good and really absorb a lot of heat....

If you set up your copper plate behind the gap... held tight with clamps.... you could reduce you wire speed by 25% and your heat by 10%..... still get good penetration but much less grinding to be done on both side.

Have you tried the heat absorbing "gel" they sell for such butt welding..... said to be fantastic at soaking heat and reducing warpage......

Do you have to change your polarity on your Mig when you change over from .035 wire to .025....?

Boob

Bob C.

[Bob Carriere]

...but perfect practice....after taking a course.... makes big difference.

Our problem is we do not do enough welding to maintain a steady hand or remember the last setting we used that worked so well.

I have given up on the expensive wire from the welding shops and have been using Princess Auto wire spools with No noticable diffenrences.... my welds are no worst nor any better. Have you noticed that Pa is now starting to carry brand names Mig tips, etc. I rent the larger tanks (Oxy-acet and argon/CO 2) from larger suppliers because I hate to run out on weekends.
Large Ar/CO2 will last a year and the Oxy/Acet usually a full set of two tanks in a little over a year....all depends how much heat we use freeing up rusted rim nuts. Fancy cuts are now done with the Plasma cutter..... now there is another tool that is very useful but requires practice and some degree of confidence to use effectively.

Bottom line my Miller Mig welder and the PA wire I use.... far exceeds my capacity/skill levels..... and the Mig is, albeit with practice, easier to use and makes you look good.

On the plus side...... I don't have to suffer from the UV/sunburns generated by the stick welder.....usually did a good job of burning you just below the face mask and right above you T shirt opening.... Ouch !!!! new meaning to "red neck"

Boob

[Bob Carriere]

.... it is only necessary to cvhange polarity when going from flux core wire to solid wire/gas.....

Wire size, within the same category of wire (flux to flux), does not require the polarity change......

Getting old...

Boob

[Bob Carriere]

A post describing your accoutrement hardly does it justice..... you must get your wife to take a full color picture of you wearing your full battle... err I mean welding outfit....!

Around the barn we wear nothing fancy..... my pants, shirt and t shirt have all caught on fire at some times or other....... and a piece of red hot slag falling in an open top safety boot will give you more rythm than a Detroit bro'

Boob

[Mike K]

Watch the mains voltage .... it can drop down .. and this means welding is just about impossible ..

The voltage can drop during peak load periods ...evening or so on .

The alternative is a DC welder powerdd by a auto engine..on a trailer

[Bob Carriere]

....when I crank up the welder and start on heavy plates the lights in the village go dim......

I was forced by Hydro and some of their crazy regulations to have a separate service for the barn as I requested a 200 amp service....... so they intalled a 16k volt line up to the barn with a transformer to step down to 220 volts just for one service....... juice I have !!!!

The down side..... I got to pay for the installation.

Major draw is the 10 hp compressor that draws 65 amps. on start up and the welder but welding is usually on lighter guage steel although the Miller will do 3/8 steel single pass.

Now that we have a "Smart" meter, I may have to do all my welding after midnight when the rates are lower......

Boob

[Speedy]

WOW Stuart! thank you! very detailed. much appreciated.
and the rest that have helped.

sorry I have not been posting, had some other priorities that stopped progress on the CJ2A.

I will indeed get back into it soon.

and Stuart post the iltis fix's also