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Progress has stalled in the last month, the garage is too cold and the atmosphere is too damp just now to consider applying resin to the moulds already made.
I could continue with the strip down of the bike as a whole but I really want to dry build it first with all the new components before I think about painting frames and rebuilding and re-painting engines which means that it is better to be patient and get the new components finished first. This is not in my nature at all.
I have been thinking a lot about the production process of producing the carbon fibre parts. When the resin and hardener are mixed you have about 20 to 30 minutes working time before the resin becomes gloopy and unusable which usually means mixing lots of small batches of resin.
If you apply the resin by brush it can take a good 10 minutes to cover an item the size of the rear hugger and you always get a striated finish from the brush which requires rubbing down. The rub down is usually quite extensive and frequently causes a breakthrough to the layer beneath. So about 50% of the resin applied ends up being converted to dust.
Also it is virtually impossible to accurately estimate the volume of resin mix required to cover the mould (although experience helps in guesstimating). Too much and you watch the quite expensive materials go jelly like in the mixing jar and worse is if you mix too little and try to spread it really thinly and it goes jelly like whilst on the job.
The answer, I think, is to prepare lots of components to cover and mix a reasonable quantity and then spray the resin. This should cut down considerably on the rubbing down. If I mix too much a second wet coat can be applied to those items already covered with a first spray. You should also never mix too little as you will only get to cover what the spray gun will deliver the resin to.
There are a number of problems with spraying though:
ELF and SAFETY - I will need a very good quality face mask to prevent my lungs becoming inelastic and to prevent my eyes glazing over completely. Now on order
Ventilation - I will need a means of removing the poisonous/carcinogenic fumes from the spray area. An old Dyson vacuum cleaner is being lined up but no design for the extractor hood or ductwork has yet been thought about
Temperature and moisture control - to ensure consistent curing time and to eliminate the possibility of the resin "blooming" if ambient humidity is high. A fan heater is obviously no good as it will just distribute dust, a paraffin heater will just distribute oily smuts not consistent with good resin or paint finishes, so electric convection heating is required. As you probably know by now I never, ever throw anything away and at the top of the loft in the garage are some old (very old, equipped with 3 pin round plugs, remember them?) convection heaters taken from the house refurbishment I will see if I can press them into service.
Dust control - my garage door faces North and even though I have lots of fluorescents and the walls are painted white I can only see well if the front garage door is open, I live near a wood and a large number of leaves blow in every time I open the garage door. Also, the past months efforts at producing moulds have left a 0.010" layer of filler dust on every surface. - The solution is to provide a tent within the garage, large enough to spray multiple components, demountable so I can have my floor space back when I have finished spraying, fed by my compressor air main and sealed relatively well against ingress of dust/leaves and self contained enough so that I am not heating the whole of west Kent.
Getting the right viscosity for spraying and cleaning the spray equipment after use - I do not know the answer to this, it will be a case of bulk deliveries of acetone to both thin the resin for spraying and for cleaning the spray gun before the resin solidifies it useless - just suck it and see?
#55
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