Proper job
how've you got the cut n shut bit so neat? hours of prep or something ingenious
Aye, there was a fair bit of head-scratching to work out a strong-yet neat(ish) cut/shut.
Prepping:
Once the Mortar tube was measured and cut (as-per pic #5, above), I then made a sleeve insert using the top part of an unserviceable MAF by lopping it off where the 'o' ring would fit. The diameter of it was a great interference fit and the wall of that part of the MAF was tapered from approx 4mm to about 2mm; ideal for seating the thick-end into the end piece of the mortar tube.
I then prepped that end piece and the cut-end of the tube it was to be mated with. This was a case of scoring the tube’s inner wall to the depth of the MAF ‘insert’, then sinking soldering iron’s tip into both mating faces and the area the sleeve would seat. This was to help the plastic-weld type epoxy get max surface area adhesion when brought together.
After curing overnight the cut/shut tube was then subjected to the soldering iron again. This was to sink holes at 110-deg around the tube to accommodate short 8mm pins going through the body and the sleeve (the pins matched the thickness of both walls combined). The pins were for added strength; 3x either side of the shut-line. They were glued into place using Araldite Rapid. The pin-holes and shut-line were then filled with Isopon and left overnight. Then the whole tube was sanded to within an inch of its life gradually working down to 1200 grit before applying a few coats of plastic primer; finishing off with a couple of coats of (smooth) Hammerite out of a rattle can..
(cut/shut close-up)
Fitting:
This was relatively easy as I’d done all the ‘head-scratching’ to fathom it out before the mortar tube was chopped up.
The first step was to put (1) an over-length bolt into the elongated threaded post which the exhaust is bolted to. When tightened up the bolt left about 2” exposed, albeit I sleeved it to match the diameter of the post (3M metal tape then covered the completed shank).
Then (2), I inserted a coach bolt through the rubber bush that the exhaust hanger would go through. This was fitted from the frame-side outwards, fixed in place with a locknut then more were added to the whole shank to make a matched diameter; finished off with the metal tape. The line of nuts also helped providing a flat mating surface for the tube’s fixing lug at that end.
Step (3) used 3x jubilee clips to fix it in place; the rearward fixing had a hard plastic block placed in between the frame shank and tube-lug to help give the tube a similar angle to that of the single-sided exhaust.
