how would you approach this weld?

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Working with copper. Welding 1 1/2" diameter copper pipe to 1/4" thick copper plate. My biggest concern is with the thick copper plate being such a heat sink that the tubing will be cooked by the time the plate is hot enough.  Its not a tight enough fit for solder and I would really like to avoid brazing it as it will be a very visible part.Although it would be a hazard what about setting the work piece up on some kind of hot plate like a propane burner of sorts the evenly get the thick copper plate hot?Any ideas?    Thanks
Reply:I would approach it like this...[ame]http://www.youtube.com/watch?v=bdnlEStyIBU[/ame]http://all-a-cart.comWelding Cart Kits and accessories
Reply:TIG braze with si-bronze, phos. bronze--whatever's compatible to theactual copper alloys involved--which you do not state.This takes less heat input that 'welding'.Blackbird
Reply:I plan on tigging it and using solid copper filler.  I just want to get equal penetration on both parts
Reply:Originally Posted by Jr_vw2I plan on tigging it and using solid copper filler.  I just want to get equal penetration on both parts
Reply:Filler wire, something along lines of Er-Cu since both pieces are copper.  Wire brush or mechanically brush really well since copper is a refractory metal and forms surface oxides like aluminum.    Rob
Reply:Could use a torch to heat. Have any of those small firebricks to set it on as a buffer?  Or place it in a vice (gently) to minimize heat transfer. Last for torch heat, start be heating a small area around pipe about 6-12" away from joint then heat plate and joint area.  Don't need a lot of heat during this stage. In navy, I used this technique when brazing joints where thicknesses were uneven.
Reply:From previous posts-the OP has a "small", DC only, scratch start machinethat just may be too small for the job.Blackbird
Reply:Many refrigeration repairmen use brazing alloys called Sil-Fos, of which Sil-Fos15 is perfect for your application. I know you said you don't want to braze, but take a look at this page before you dismiss the idea fully:http://www.silfos.com/products/catal...-p-1-c-62.htmlThe color of the alloy, after cleaning, is nearly if not exactly the same as the base metal.
Reply:Originally Posted by dave powelsonFrom previous posts-the OP has a "small", DC only, scratch start machinethat just may be too small for the job.
Reply:I would grind..file..sand..whatever it takes to get a GOOD flat joining area and silver solder it..Your best bet.Done right there is nothing left to look at.That's how I approach it....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.