Welding HELP!

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Here is my first weld. Its the Cowl section of a 66 Mustang. After grinding, noticed many holes in my weld. Am I grinding correctly? I used a firm grinding disk and then finished with a flexible sandind disk. Also, using lowest heat yet the metal is still showing signs of warp.Lincoln 175 using gasWire speed 2.3Healt is low.Also, what PSI on gas should I be using?Thanks
Reply:You won't measure your gas flow with PSI; it should read it in CFH, cubic feet per hour.  Indoors with no wind, you should be between 15 and 20 CFH, but if you have porosity, you need to take it up until you don't, but too much can cause porosity from turbulence, too.
Reply:Your picture could be cropped and resized to make it much easier for expensive dial-up people like me to look at.  It doesn't look porous, it just looks like not enough heat/fusion.What wire size are you using?  What is the thickness of the part?
Reply:Sorry about the pic, just learning to post.I'm using .025 wire and the metal is 16 gauge I believe. The using 7CFH of gas according to the guage. Showing a little metal warp as well
Reply:turn up your gas, about 15-20 CFH, keep your heat low, and practice on a piece of scrap before you do the "good stuff".it looks like you need to slow down a little. almost looks like you are shaking your hand when welding, like you are scared of the arc. take your time and be patient... the warpage comed from the heat... if you were to do a series of "tack welds", it woudl be better. also, are you dragging or pushing the welder? after you practice on running a single, straight, consistance bead, try "weaving". it looks better and helps the penetration. also, make sure the metal that you are welding onto is clean before you start... grind it till it's shiney. as far as your post-weld grind... take a picture, THEN grind the bead off... it'll be easier to see what you are doing wrong. when you grind the bead off, try to go in one direction... i tend to line the bead up with my body, then from the furthest possible point on the bead, i drag it towards me. as far as using a flap wheel/flexible disk, it's not neccisary to use it until you need a good cosmetic finish. the hard disk will work just fine... jstu be care ful abou tit skipping up and grabbing you...http://www.weldingweb.com/vbb/showthread.php?t=16548check out what mine did to my sweatshirt. lot sof safety advice in this thread.later,Andy
Reply:I turned up the gas and then tried to close the holes you see in the pic...some of the holes closed quickly but, towards the center of the seem, a hole about the size of a dime formed. I slowly spot welded and with a lot of tip movement and some trigger squeezing off and on, closed the large hole. Now there is a large glob of weld material where the hole was. Will this glob grind down and do you think the hole formed because I had grinded the prevous weld to much? Heat by the way is low.
Reply:All globs will grind!  It's the wondering if there is steel underneath the glob that is the real concern!  Let us know.  Learn how to be your own pulser.  Pulse the trigger, give it just a half-second to cool, and repeat.  It won't take that long to run a nice bead in 16-ga.
Reply:in order to be a good weldor, first you always learn to be a good grinder  DavidKeep at it, you will get it.  Nice for the first time.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Oh, and learn how to stop before the hole gets to be the size of a dime!
Reply:I doubt if Ford started out with 16ga sheetmetal on a cowl panel.  A gusset, perhaps.  In any event, these things in your pic stand out to me like a sore thumb:  Lots of rust has made the metal thinner than when it was new.  The area marked #1 doesn't look like it was ground until after the weld.  Sand or media blasting is an alternative for rust removal.  There's bound to be rust on the side we can't see.  If it was not removed, it will interfere with the welding puddle...the typical snap, crackle and pop of improperly cleaned metal.  A backup strip behind the seam might help if you can access that area.Those blue spots marked #2 and #3 are where the metal is paper thin.  Even if corrosion treated from this side, it won't be long until it rusts through from the back side again.I don't think you could have picked a worse specimen for your first weld.  Good luck!WeldingWeb forum--now more sophomoric banter than anything else!
Reply:i respectfully disagree with 69 Chevy. yes... the coloration is there for a thin piece of metal, however for being a beginner, it is safe to assume that you may have just been applying too much pressure with your grinder and/or kept the grinder there long enough to heat the metal... you can get that coloration on 1/4" stock if you press hard enough... the colors you see are a result of heat, not metal thickness. like i said, i RESPECTFULLY disagree... i don't want to step on anyone's toes.I do however concur with 69's assement that the spot next to #1 seems to not have been ground before the metal... i like i said before, clean the metal first, then weld. the rust interferes with the arc and gives poor penetration and/or weld quality.later,Andy
Reply:Originally Posted by aczeller... the colors you see are a result of heat, not metal thickness.
Reply:Originally Posted by 69 chevyWould you care to explain, using your decades of autobody experience as an example, just how those blue heat spots on the parent metal got that way if NOT being too thin?  The bubblegum weld beads were the highest points, got ground the hardest and longest, yet didn't turn blue.  Why is that?
Reply:the holes in your weld are most likely caused from not cleaning the rust off the area to be welded. your gas looks ok, your weld would look like a sponge or swiss cheese if your flow rate was too low. try to wire brush off the rust and then weld. if you have some scrap metal try welding one that is rusty and one that is shinny metal.you should see the difference. as far as thinning due to rust, it takes 7" of rust to equal 1" of steel.
Reply:Originally Posted by qaqcas far as thinning due to rust, it takes 7" of rust to equal 1" of steel.
Reply:Originally Posted by aczellerwhat do you mean by that? does metal expand to 7 time its original size when it rusts?just curious. i honestly have no clueLater,Andy
Reply:Originally Posted by HT55I think what qaqc is getting at is, it takes 1" of steel to create 7" of rust.  Or, for every 1/4" of rust there is a loss of about 1/32" of base material.  Hope I got that right and helped out.
Reply:It is true that the welded area was not cleaned before welding. I have the old cowl hat that I took out a tried welding a bead on it. My welder simply burned holes with very little bead. The surface was also un-cleaned and it popped alot as well. I did have a piece of 1/2" steel that I practiced running a bead on and it went much better. I was able to turn the heat up and wire speed up also. Practice  welds on this larger piece looked very good and I could see a puddle form. It seems much easier to lay a bead on the heavier steel.The lower cowl is not likely to be visible once the cover is on and entire area is coated with POR-15 and topcoated I am concerned about water running smoothly out of the cowl with the warpped metal at the weld and uneven weld. Ever heard of using a little body filler in this area?
Reply:Originally Posted by 69 chevy
Reply:Originally Posted by sunpacceoI am concerned about water running smoothly out of the cowl with the warpped metal at the weld and uneven weld. Ever heard of using a little body filler in this area?