Has anyone welded intake port floors?

[My427stang]

So wait.... are you saying you don’t want to use epoxy?

It also clashes with my cork end gaskets

[Falcon67]

So wait.... are you saying you don’t want to use epoxy?

It's not completely clear I think, have to read the comments again.   

Sorry, not saying you must do whatever either way, just stating that nobody I've seen uses welding.  The epoxy is quicker and easier to shape - and easier to remove - when playing port engineer on an intake or cylinder heads.  I'm quite sure no one here will object to any method you chose to achieve any results you desire.  "You pays your money, you gets to take your choices".  Share the results and we'll get a cup of something, sit around our warm LED displays and chat about it.

[falcongeorge]

I've welded runner floors and roofs also, with both MIG and TIG.  I wouldn't try it with MIG again, lots of porosity, hard to control, etc., TIG is way better.  The trick is to preheat the aluminum in an oven, I have heated at 300 degrees for an hour or so.  Then, when you pull the intake out of the oven, wrap it in a welding blanket so that it maintains the heat.  Only expose the port you are working on, and when finished cover it with a blanket, expose the next port, weld, repeat.  Keep it covered after welding until it is completely cooled down.  Figure on removing 0.040" to 0.060" on the flange to square it up when finished. 

I've had to do this with a couple of Dove intakes, where the aluminum was rather questionable, hopefully a Port-O-Sonic would be easier.  But its a painful process in any case.

I know you don't want to use epoxy, but in your situation I would.  You have to understand that although the epoxy doesn't have perfect adhesion to the aluminum, it does adhere to itself very very well.  So, you grind away part of the face of the manifold at the floor, fill that depression with a thick tab of epoxy that will be sandwiched between the intake and the head, then fill the floor of the port.  Even if the epoxy wants to try to separate from the aluminum, that tab will hold it in place.  Use Splash Zone epoxy, and I don't think you'll ever have a problem with that fill.

Thanks guys, I will think about it

BTW, I realized my USAF experience had me screw up my abbreviation.  I have a MIG, metal inert gas welder, not a MiG, Mikoyan-i-Gurevich Design Bureau fighter aircraft....although I'd probably dump the Mustang if I had a modern one to play with....

The only way a MiG is going to fit is if you are working on a tunnel port intake...

[Falcon67]

Fill the port with mix, crank up the gas and run that stick out waaaay out there.   

[falcongeorge]

Fill the port with mix, crank up the gas and run that stick out waaaay out there.   

I don’t think you saw what I did there...