I'm not sure how Tilley extended the air tube on these heaters, whether they had an extension or if the tube was a longer one piece. There was some good info this company with these sizes. The 17/32" OD tube fit, but was a tad loose. So I chamfered the ends, cut it length-wise and "sprung" it a bit. This resulted in a nice tight fit. When I bunsen tested the burner, I did not detect and venturi effect by the internal coupler. Solution 2 (easier) would be to slip an extension over the existing tube. The 21/32" OD tube fit perfectly over the existing tube. (I did not cut this tube to length) Dan
Hello Dan, I actually found it quite easy to roll the sheet brass around a 1/2" dia. bar, eg a bolt. Grip the end of the bar and sheet in a smooth jaw vice and tap it round near to the vice jaws. Using a piece of hardwood and a hammer. Then saw of the excess. You might no get it right on the first time like me. Silver solder up the seem. Job done. You will then have an exact replacement. Once the joint has been cleaned up you won't spit the join. Just for the record the tube on the earlier IF54 is the same but 5m/m longer. Yours, Maurice.
