Saturday, January 31, 2015
Cobra Torches) oxy-acetylene torch. In 20+ years I've never used the cutting attachment so this is a great chance to play with it. The literature says it cuts better than a plasma cutter. Like I ever believed that. I set it up and practiced a bit with it to see how fast to move while cutting, etc.
I then clamped a piece of angle to my practice piece of 3/16" steel to use as a guide to simulate a fixture for guiding the angle of the torch cut.
Thursday, January 29, 2015
I've had a lot of ideas for how to do this. Slowly the complicated ideas have all been abandoned. The easy way is probably how the factory did it, just a hammer and a dolly.
The ends were trimmed with the snips where the angle formed at the end of the lower shell was less than 90 degrees.
The first step is to hammer the edge down at about a 45 degree angle. This gets hammered around the lower shell, in steps of about 30 - 45 degrees, until it is past 90 degrees.
Handy-T Dolly from Fournier ( a present from the grandkids). It fits the 3/8" radius in the corner of the shells so it won't nick them.
With the shell resting on the dolly the fold is completed and then hammered tight.
Again you just work back and forth over the length of the seam slowly bending it over. The steel is soft enough that it stretches without cracking,
The edge looks wavier as you work because the outside edge is longer and the steel needs to be shrunk to make the fold.
You can see how trimming the end of the upper shell left a nice end to the fold.
Simple still seems the best way to make things.
Sunday, January 25, 2015
The vertical took a little work to balance it but once i figured it out it worked great.
All the shells are welded and the inlets look good, well aligned and squared.
On to the Outlet Elbows.
The first one I welded I used clamp blocks and a c-clamp to hold everything tight while I welded the overlap.
I don't know if it mattered but I didn't want to cause any misalignment by welding one side and then the other.
They seem bigger then the old one which was missing most of the elbow.
This is fun.
Saturday, January 24, 2015
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.
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.
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.