I tried a few times and didn't have the nack of glassing. You would probably have to have a mold for the outside if you want it smooth, I built an awesome road bike and used a homemade outside mold but it broke at the chainstay. The coolest bike I made was with hollowood tubing and custom internal alum lugs to hold it together, woried about the weight so I built it trying to reduce weight and it came out wimpy and weighing about one pound, could have beefed it up.