Learning points - part 2

Applying the hemp
Applying the hemp and epoxy is very messy – I recommend you use small batches of glue. I also recommend wearing clothes that can go straight into bin when you’ve finished (I didn’t do that and now have very stiff sleeves on my overalls)!

Check the underside of the wrapping as you go – I left two big gaps on the underside when wrapping the headtube joint. I had to add more epoxy via a second gluing 24 hrs after the initial gluing. I also added more hemp & epoxy to the bottom bracket area which I felt looked less strong than other areas. When doing a second gluing, take care not to get epoxy in the inside of the metalwork (especially the bottom bracket). I used sponges tightly wedged into the metal ensure they stayed clean.

To wash the epoxy from your hands I found vinegar very useful. You could use white spirit and then rub with moist wipes (of the type you find in packs of kitchen/surface wipes). If you get any epoxy anywhere it shouldn’t be, you can get it off with vinegar if it hasn’t fully cured.

Don’t make the mistake I made – I had to go out after the hemping process and ended up leaving the wrapped epoxy for about 7 hours before I came to take the tape off. It was almost fully set by the time I came to unpick it. As a guide, if you are doing it outside, I suggest that at around 20 degrees leave it for about 3 to 3 ½ hours.

Make sure you use good quality tape and wrap the electrical tape the right way round (i.e. with the non-sticky side against the hemp) – I messed up one of the chainstays, and owing to the fact that it had set, it was extremely difficult to pick off the tape. Avoid using very thin tape - if it breaks and struggles to come off the roll easily, it might be to thin and could be difficult to get off the lugs.

When you come to clean up the fully dried hemp lugs, gently prising the reluctant tap off with a 1/4 inch thin chisel worked really well (again from ebay). Also, this is where a dremel and sanding drum might come in handy - if the epoxy has fully hardened, you can just sand off any rogue electrical tape - easy.

Sanding
I decided to smooth and paint the hemp lugs. I used a dremel and also sanded by hand. Don’t file down the hemp too much as that would affect the strength. I didn’t file much of epoxy at all (only the odd spiky lumps really). I then applied Autocare easy-sand car body filler (£6 from ebay or Wilco). I then sanded the filler and applied primer, applying two coats of primer (using a poundland brush-set). I probably should have done more sanding and filling but got a bit bored and wanted to get it finished. It is probably best to have more patience than I displayed.

Painting
I then painted the lugs black (a poundland primer and two coats of black car paint applied with a brush). The paint I used was cheap auto paint from Poundland (although I used ‘spray paint’ I sprayed batches into a tub so I could apply it as a liquid with a brush. This was done only because it was the cheap option. The finish was perfectly adequate (for me).

Decals/Stickers
I made my own decals using powerpoint and some print-yourself adhesive acetate sheets (from ebay). Standard printer ink isn’t waterproof (laser printing is waterproof) so I stuck a clean piece of the adhesive acetate on top of the printed sticker sheet. I’m hoping that the sandwiched sheets are waterproof.

Lacquer
I finished the bike by applying lacquer finish by spray to the whole bike frame (before attaching the wheels, forks etc).

Frame weight
The cleaned up frame weighed about 2.7kg and felt reassuringly strong.