I mentioned this in optimusprime 's Skip rescue thread, but I thought I'd start a thread for it seperately.
The company I work for previously imported bicycles from big names such as Rocky Mountain, Merida, DK Bikes, Norco etc. They haven't done so since before I started, but they still had some old frames etc hanging around. Last week, they decided to clean up the mezzanine floor and one of these frames, a carbon Merida Mission or flex Team like this one.
mtb by Sciclone, on Flickr
Except, this particular one had some cracking of the carbon near the rear derailleur. Because of this (as well as it was probably warranty job for a $4500 bike at the time), before putting it in the skip, they had to slice the frame in half.
I like to fix things, and have wanted to learn how to use composites for a while, so I took a dive in the dumpster and grabbed the frame out.
So last week I ordered an epoxy resin sample set and some carbon fibre tape/fabric from a localish boat supplies place. I figured if I fix it great, I get a nice light frame I can turn into a commuter bike, if not, I've only spent $50 and learnt a little about composites.
On Tuesday, I went out to the shed. Carbon fibre and composites in general make very fine dust, so before starting I borrowed a proper respirator dust mask from a mate that has been playing around with them.
After much sanding the rear crack looked like this:
20151124_164514 by Sciclone, on Flickr
There's not many pictures of the next step, as resin goes off fairly quickly in our heat and humidity and I mixed up only enough to flow into the crack and pregnate the carbon tape. Plus I didn't want resin on my phone..
After wrapping a length of tape around, I then wrapped some electrical tape around to squeeze the excess resin out.
20151124_165958 by Sciclone, on Flickr
20151124_170009 by Sciclone, on Flickr
On the recommendation of my mate, I left it til the following afternoon to unwrap.
I unravelled the electrical tape, and some had gotten stuck in the resin so it looked like this:
20151125_162736 by Sciclone, on Flickr
Not a big deal, as I have to sand it anyway. Cue more sanding..
Which left it looking like this:
20151125_165801 by Sciclone, on Flickr
20151125_165811 by Sciclone, on Flickr
20151125_170112 by Sciclone, on Flickr
Not too bad for a first attempt, and more than strong enough. Sure it's not pretty, but fill in the lows and cover it in paint and no one will know..
Buoyed by my success, I then turned my attention to the front cuts. I was going to try making a jig to hold the frame while I resin fill it, but the top and down tubes are odd shapes. As this is epoxy resin, I will instead be making up some polystyrene "plugs" to join the two halves of the frame together. I didn't have any on hand so I just spend a bit more time sanding down the areas in preparation for the plugs and some more glassing. There was a couple other areas where the clear coat had come off, so any left over resin will be used to fill these areas. Purely cosmetic, so I'll sand them back and paint the whole frame at my leisure.
20151125_170132 by Sciclone, on Flickr
20151125_174417 by Sciclone, on Flickr
Hopefully I'll get some time this weekend, because even though we're moving house next week, except for my tools, I don't have a lot else to pack.
The company I work for previously imported bicycles from big names such as Rocky Mountain, Merida, DK Bikes, Norco etc. They haven't done so since before I started, but they still had some old frames etc hanging around. Last week, they decided to clean up the mezzanine floor and one of these frames, a carbon Merida Mission or flex Team like this one.
mtb by Sciclone, on FlickrExcept, this particular one had some cracking of the carbon near the rear derailleur. Because of this (as well as it was probably warranty job for a $4500 bike at the time), before putting it in the skip, they had to slice the frame in half.
I like to fix things, and have wanted to learn how to use composites for a while, so I took a dive in the dumpster and grabbed the frame out.
So last week I ordered an epoxy resin sample set and some carbon fibre tape/fabric from a localish boat supplies place. I figured if I fix it great, I get a nice light frame I can turn into a commuter bike, if not, I've only spent $50 and learnt a little about composites.
On Tuesday, I went out to the shed. Carbon fibre and composites in general make very fine dust, so before starting I borrowed a proper respirator dust mask from a mate that has been playing around with them.
After much sanding the rear crack looked like this:
20151124_164514 by Sciclone, on FlickrThere's not many pictures of the next step, as resin goes off fairly quickly in our heat and humidity and I mixed up only enough to flow into the crack and pregnate the carbon tape. Plus I didn't want resin on my phone..
After wrapping a length of tape around, I then wrapped some electrical tape around to squeeze the excess resin out.
20151124_165958 by Sciclone, on Flickr20151124_170009 by Sciclone, on FlickrOn the recommendation of my mate, I left it til the following afternoon to unwrap.
I unravelled the electrical tape, and some had gotten stuck in the resin so it looked like this:
20151125_162736 by Sciclone, on FlickrNot a big deal, as I have to sand it anyway. Cue more sanding..
Which left it looking like this:
20151125_165801 by Sciclone, on Flickr20151125_165811 by Sciclone, on Flickr20151125_170112 by Sciclone, on FlickrNot too bad for a first attempt, and more than strong enough. Sure it's not pretty, but fill in the lows and cover it in paint and no one will know..
Buoyed by my success, I then turned my attention to the front cuts. I was going to try making a jig to hold the frame while I resin fill it, but the top and down tubes are odd shapes. As this is epoxy resin, I will instead be making up some polystyrene "plugs" to join the two halves of the frame together. I didn't have any on hand so I just spend a bit more time sanding down the areas in preparation for the plugs and some more glassing. There was a couple other areas where the clear coat had come off, so any left over resin will be used to fill these areas. Purely cosmetic, so I'll sand them back and paint the whole frame at my leisure.
20151125_170132 by Sciclone, on Flickr20151125_174417 by Sciclone, on FlickrHopefully I'll get some time this weekend, because even though we're moving house next week, except for my tools, I don't have a lot else to pack.
