My solution:
I wanted to put those cool BSA Gold Star Plastic badges on my tank. But it’s a 5 gall alloy Lyta, so there’s no screw fixing bracket on the tank, and no flat section or bracket to screw the badges to. So here’s my solution.
I wanted this whole thing to be ‘reversible’ ie- no welding and the ability to unscrew and replace the badges if needed. So I made the following:
It goes like this:
1 .Position and align a tank badge on one side. Tape it in position.
2. make a paper template -cut around the badge circle the correct diameter hole for the badge. Tape on the paper template around the badge onto the tank.
3. mark reference lines on the template for the tank shape in pencil and add horizontal line of screw hole centres. This is all for alignment - you can turn it over using your reference marks for the other side, both sides are the same. The most important thing is to align the badge mounting holes parallel with the lower edge of the tank - so they’re both aligned horizontally.
You need pencil alignment guides, so now remove the template and hold the template against a window ‘back to front’ so you can trace the alignment lines onto the reverse side of the paper.
4. fabricate two alloy strips - 3mm thick is about right, by about 10mm wide and length to span the badge mounting holes, 3mm thick ally is enough meat for a 4BA screw to screw into.
The ally brackets need slight bends that match the inside contour of the badges.
5. Drill and tap for 4BA, using the badge holes as the alignment for drilling. The alignment and angles drilled and tapped need to be accurate.
6. Out of an old inner tube make x2 rings that will glue just inside the badges back ‘lip’. Glue these into the backs of the badges using cyano glue or contact adhesive.
7. Make x4 small rubber ‘washers’ that will fit behind between the badges and the aluminium brackets, for vibration insulation.
8. Using your templates you can now mark the holes on each side of the tank. Best trick here is to position the badges- aligned and taped on and just dip the end of a cotton bud in paint, push the cotton bud through the screw holes and you should have perfectly aligned marks that will later be used when you glue the ally brackets to the tank.
Take a breath… pour another glass…
Now. assuming you have your 4BA screws are cut to length (Obviously they need to be short so they don’t contact the tank at all when tightened (not too tight- just a gentle nip), and nicely dressed so they enter the threads in the ally brackets easily).
The alloy strips need to be glued on to the tank -I used 24 hour Araldite. The tank surface needs to be thoroughly roughed up with 80 grade sandpaper, and the glue spread over a wide area, (but obviously not out as far as the rubber outer ring that’s on the badge, and not only behind the strip, - run a bead of glue over the top of the strip (outside) as well. You can use a thickener in the Araldite like Microballoon or flock powder. And do each one level I.e with the tank on it’s side so the glue doesn’t run.
It’s harder to explain than do! But the idea is to isolate the delicate plastic badge from the metal so vibration doesn’t shatter it.
Remember what I'm doing here is making it so the badge can be replaced... It's not just sticking the badge onto the tank. You stick the alloy bracket only, so the badge can be replaced, and it's isolated from vibes.
Once I fitted it I made rubber trims out of mudflap rubber (tricky cut!) mounted behind the lower half of the badge to make it look 'complete'.
