I've been told many place surface flanges with a large belt sander.
The one at school is real narrow, like a 3" wide belt and it has a horribly sunken backing plate so surfacing flanges would be pointless on that.

However this craftsmen belt sander has a nice wider and higher backing plate that would keep the belt flat when laying a flange on it. The belt wouldn't be able to "cup" the flange leaving a convex surface.

http://www.sears.com/shc/s/p_10153_1...ch+Power+Tools

Anyone see any reason why this wouldn't work? I'm considering getting something like this when it comes on sale or somewhere else when i can get it cheaper just to surface the new downpipe flanges and w/e else I deem necessary.
The local machine shop wants a million dollars to do a single flange and I basically gave them the finger when they told me how much they wanted. Then asked him why I should pay him for an hour of shop time when all he does is hold the flange on a belt sander for 40 seconds at the most. I understand getting paid for your work but that is stupid.

 

That's not a bad price for those specs for a craftsman - I have seen a similar Enco unit for ~$40 less on sale with free shipping in their flyer.

 

I'll keep that in mind if my **** doesn't seal up like it should. I figure after being bolted down tight and heat cycled a few times they might need surfacing, we'll see. They might just flatten right out again. (They're not really warped much, just be being curious while wanting more tools in my living room.)

FWIW, someone just reminded me. When BEGI sent me that downpipe all the flanges had been touched to a belt sander after welding to clean things up.