silica puddle in weld end??

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I'm welding a 5/8" button weld, circling and overlapping the bead. The job tolerance is 3/32" max weld height. To achieve this I'm  running very hot. This creates a large silica puddle, leaving an indention at the end of weld. Can anyone suggest how to fix this?Miller TrailBlazer 251Miller HF-250-1Miller MaxStar 150 STLHyperTherm PowerMax 380 plasmaLincoln PowerMig 180Millermatic 252Miller Diversion 180
Reply:material ?process ?filler ?insert thoughtful quote from someone else2000 Thermal Arc 300GTSW 3.5 hours1946 Monarch 20 x 54 Lathe1998 Supermax 10x54 Mill2004 Haco Atlantic 1/2" Capacity Lasernot mine but i get to play with it
Reply:I"m going to assume this is some kind of GMAW or FCAW weld.  The pit at the end of the weld is shrinkage, which I figure you already know.  The only way I know of to correct that is pausing at the end of the bead, and filling the puddle up some.  3/32" is sorta tough to get without grinding.  I'm also assumeing that you don't want to grind because you have a whole bunch of these button welds to do.You should see less shrinkage if you can run a bit cooler, but you mentioned you're intentionally running hot.You could apply some preheat, and this should reduce the shrinkage you're seeing.  But this will also slow you down, and you could see some distortion elsewhere; which may not be acceptable...Nope, I think you're going to have to over fill the button and then grind it down flush...Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:I'm assuming since you mentioned silica you are using hard wire. If it's practical you can do it in more than one pass and clean the silica islands inbetween passes. There are some wires that produces less islands than others. 5/8 is decently big I don't really see why u would have to run hot to get the cap under 3/32 tall. By hot what are we talking anyway? I'll run fillets on 16g carbon steel at 20v /300+ipm/,035 in all positions. I've done waaaayyy hotter than that in some cases. so its all relative. mat thickness?process?setup?pics?I say multipass if you really hate grinding and can be super consistant. Otherwise, bust out the grinder.Last edited by i4sillypwr; 08-24-2009 at 11:20 PM.
Reply:ive noticed turning your voltage down will reduce that problem. is the silica trapped in a little tiny hole? because thats the only time i would be concerned about silica deposits at the end of my weld. if there is no hole which the silica is trapped in try breaking it free with your nozzle. if it has the material at the end im willing to bet it has it throughout the whole weld right?
Reply:Originally Posted by chenrymaterial ?process ?filler ?
Reply:Just a thought (and it might not help you at all), but I TIG a bit with er70-s2, and find silicon puddles like you, but never in an objectionable amount.However, er70-s6 contains more than twice as much silicon as s2 (even though s2 is more strongly deoxidizing for other reasons).  The added silicon in s6 makes it flow more, but maybe using an electrode with less silicon would reduce your problem?
Reply:i would suggest changing away from the s6 and adjusting your parameters, are the parts your welding clean and free from scale ?is TIG a possibility here ?insert thoughtful quote from someone else2000 Thermal Arc 300GTSW 3.5 hours1946 Monarch 20 x 54 Lathe1998 Supermax 10x54 Mill2004 Haco Atlantic 1/2" Capacity Lasernot mine but i get to play with it
Reply:Rather than using a standard button weld which fills in the center too, maybe the end of the rod needs a rounded chamfer so just the outside is being welded. Less weld means less silica. This could be incorporated in the cut-off operation by using a forming tool with a cut-off projection, I'd think, so not require a second operation.
Reply:yeah I think -2 wire is your best bet. Are they not ok with it being under flush? Center of that button weld isn't doing a whole lot anyway.
Reply:well im sure he cant change wire, thats probly what the procedure calls for. I would simply hit it with a grinder, say a die grinder.. then its gone.
Reply:Wagin,Can you post a picture?
Reply:try grinding the mill scale, that should cut down on it. i guess i just dont see what the problem is. its natural to have this in your weld.
Reply:More Fill.Or is it possible you may have some smut?If so check this outhttp://www.finishing.com/2600-2799/2784.shtmlhttp://www.thefabricator.com/Aluminu...cle.cfm?ID=554Last edited by pistolnoon; 08-26-2009 at 03:19 AM.Reason: New links
Reply:Originally Posted by rlitmanJust a thought (and it might not help you at all), but I TIG a bit with er70-s2, and find silicon puddles like you, but never in an objectionable amount.However, er70-s6 contains more than twice as much silicon as s2 (even though s2 is more strongly deoxidizing for other reasons).  The added silicon in s6 makes it flow more, but maybe using an electrode with less silicon would reduce your problem?
Reply:Originally Posted by Oldiron2Rather than using a standard button weld which fills in the center too, maybe the end of the rod needs a rounded chamfer so just the outside is being welded. Less weld means less silica. This could be incorporated in the cut-off operation by using a forming tool with a cut-off projection, I'd think, so not require a second operation.
Reply:Originally Posted by chenryi would suggest changing away from the s6 and adjusting your parameters, are the parts your welding clean and free from scale ?is TIG a possibility here ?
Reply:Originally Posted by maartyWagin,Can you post a picture?
Reply:Wagin,I read the thread again and another possible solution occurred to me.  There are some metal core wires that are designed to produce little or no silicon islands.  Hobart makes a product called Vantage that is designed to produce no islands, or small islands that are self-peeling.  Here's a link to the product data sheet, if you're interested.http://www.hobartbrothers.com/pdf/da...loyVantage.pdfOther manufacturers may produce similar wires, but I don't know their products off the top of my head.The downside to metal core is you may have to buy a larger spool, and the cost/lb is higher than other types of filler metals.  This will only work if you're doing enough of these to justify the added cost.Maybe your local welding supplier can connect you with a demo of the product, or you could call the customer support number for Hobart and maybe they can help you out with a small sample of the product.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Originally Posted by A_DAB_will_doWagin,I read the thread again and another possible solution occurred to me.  There are some metal core wires that are designed to produce little or no silicon islands.  Hobart makes a product called Vantage that is designed to produce no islands, or small islands that are self-peeling.  Here's a link to the product data sheet, if you're interested.http://www.hobartbrothers.com/pdf/da...loyVantage.pdfOther manufacturers may produce similar wires, but I don't know their products off the top of my head.The downside to metal core is you may have to buy a larger spool, and the cost/lb is higher than other types of filler metals.  This will only work if you're doing enough of these to justify the added cost.Maybe your local welding supplier can connect you with a demo of the product, or you could call the customer support number for Hobart and maybe they can help you out with a small sample of the product.
Reply:You can't just hit it with a wire wheel to get the silica off?MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by DesertRider33You can't just hit it with a wire wheel to get the silica off?