Gas Welding Exhaust Manifold Joints

 Before clamping the shell assembly back in the alignment fixture there are some inside corners which need trimming.

The finished edge is created by folding the longer flange on the top shell over the shorter flange of the bottom shell.  It's not possible to do this in the tight inside corners.  The factory just trimmed off the longer flange in these corners and gas welded the corners.

I used the nibble to clean out the corner.

The shell was then pushed back onto the inlet alignment fixture and clamped to hold the inlets tight to each block.

Before welding I closed up any small gaps.  It makes welding easier if the edges of the 2 shell halves fit snugly together.

The steel is soft enough it is easily moved with light taps of a ball peen hammer.

 The hardest part was propping the heavy fixture and shell at angles which made welding each seam easy.  I believe the combination of spot welds on the flanges and gas welding the small areas was faster than welding the entire edges.

You can see from the heat affected zones where the 7 seam were gas welded.

Next will be to weld on the outlet elbows.  We're getting there.