Well, given the location is it heavy load bearing area? Could he skip the pulling and the like and just epoxy it back together and then machine it in place to a smooth transition with similar texture or surface as the other ports. JB Weld can hold up to fuel and can be easily machined with hand tools or power tools, I would think a long (3" =75-76mm long) sanding drum like woodworkers use with a 1/2" ID on the sanding drum for the sanding sleeves work well for the machining part if it is flat in that area. A dremel could easily do it but they are too small and it would be easy to impart a dip whereas, a longer drum could give you the stability and access... depends upon the contour. A dowel center or bolt center with a washer that is the id of the sanding sleeve diameter with two washers to compress the rubber tubing (washer or fuel line that isn't braided, a thick walled rubber tube is needed) over a screw that is sleeved with brass or aluminum with fender washer sized to be a tight fit to the bolt but smaller than the ID of the sanding sleeve so you don't compress the sleeve causing it to fail. A latex balloon could be used to make the diameter a tiny bit bigger if your tubing is just a few .01 mm off of a slip fit to the ID of the tubing.
The rubber for the drums is a high durometer rubber that is denser than most RTV and other material...
to fabricate your own drum sander like the woodworkers use that could be used in a drill with extension shaft then you size the tubing to slide over the threads with a snug piece of brass or aluminum, or steel tubing over the threaded portion where the sanding sleeve will be. That has a washer on the bottom cut to engage the carriage bolt's square or file it to fit two spots of V with other shoulder filed away so it is a round center with Vs cut into washer to engage the carriage bolt and not spin. The excess shoulder of the carriage bolt head is cut or filed away so the sleeve slides down to the washer. The domed head of the carriage bolt needs to be several mm smaller than the sleeve ID (inside diameter).
Carriage bolt on bottom that is dome faced with OD of the head needs to be several mm smaller than the ID of the sanding sleeve.
The tubing is a slip fit into the ID, the 2nd washer on the bolt shaft is the compression device and then a nut makes the tubing bulge slightly making the sleeve have a tight non-slip fit to the sanding sleeve.
black rubber tubing or a cast piece is used on the sanding drum, similar to the dremel drum a larger size for the woodworkers model of course.
So, your bolt need to be large enough to be rigid and not bend when side pressure is applied, most small bolts don't have that strength, as they aren't designed for heavy loads so they are generally soft steel alloys or similar. The dremel uses a hardened steel arbor for the rubber sleeve. You could harden the steel in a bolt if you could find out the metal used, or make one from soft T6061 and then harden it to T10 or similar level of hardness if you have an oven capable of holding a 600-700 degree F temp for 30 minutes you can harden or anneal T10 T6061 aluminum. Then the quench determines the hardening if you need to harden it then you quench or in the case of some metals take the temp to a certain range for length of time.
Just a thought...
Cruder method of sanding sleeve with dowel cut with thin fine blade like on a bandsaw or thin kerf coping saw or similar. The cut being straight down the middle. Slip the sandpaper in the slit after wrapping around the dowel and then wrap the paper so it tightens when spun and the sandpaper strip will hold against itself. It isn't as smooth as the sanding drum but is far cheaper to make and if you have a thin kerf saw like a Japanese pull saw it can cut the dowel with a very thin slot. A wide slot won't work as it has too much play. Two layers of sandpaper needs to fit fairly firmly in the slot for this style to work without problems when using. 3/8" dowel would be the smallest I would attempt to use (~10-11 mm wooden dowel rod).
David
