Bike Frame Project Questions

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Bike Frame Project Questions

Author	Message
FrameFudger	FrameFudger posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 8, Visits: 51	Hi, Got my tubes made, been using 100gsm hi-mod UD CF. next step is to jig them and epoxy the joints together and then fillet the joints, also need to epoxy carbon fibre to a titanium bottom bracket shell I am using... Bottom bracket Shell Will be wrapped in pre-preg UD CF. Want to make sure the bond between the titanium and CF is stronger than the just the pre-preg resin. So which epoxy to use? Tube joining Tubes will be mitred and then fit flush to each other. Once they have been glued I will then be wrapped further pre-preg UD CF around the joints, so the epoxy needs to be generally strong with a little flex, however will not be the only structural element taking force and load. I was looking at the ET515 Epoxy Adhesive, but I am not sure if this is the most suitable? http://www.easycomposites.co.uk/products/structural-adhesives/semi-flexible-15min-epoxy-adhesive.aspx If not what would you suggest? Joint filleting Prior to wrapping the joints in further UD CF I need to fillet the joint so there are no sharp acute angles which could create a void after wrapping and curing. Similar to this... What filler \ epoxy combination would you suggest, as this isn’t structural the lighter the better. Look forward to your responses. Cheers, Andy
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Hanaldo	Hanaldo posted 10 Years Ago Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	You could use whatever epoxy laminating resin you are using to wet out the fabrics, and thicken it up to to the viscosity you need with carbon fibre powder and some cab-o-sil (fumed silica). However that possibly won't be very easy to sand, so if you need it to sand easier then maybe use glass bubbles instead of the fumed silica.
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FrameFudger	FrameFudger posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 8, Visits: 51	Tubes are made from pre-preg UD so I need a suitable epoxy to create the fillets. Also what kind of % weight quantities of Carbon Powder to Epoxy to Glass Bubbles would you suggest?
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progetto	progetto posted 10 Years Ago Post Details
Group: Forum Members Posts: 6, Visits: 231	Mix your epoxy and micro balloons to the consistency of putty, ideal to fillet the joint with. The fillet doesn't need to be super big, just enough to take away sharp edges. Google Velocipede salon Carbon building, it is a great thread by Nick Crumpton, one of the worlds premier tube to tube frame builder.
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f1rob	f1rob posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 237, Visits: 4.8K	If you wrap your bottom bracket have a cf ply on the ti you will have a lot better bond than u/d Glue wise best choice would be a pre preg film glue fm87 would be perfect but depending on the glue you use for bonding you might want to go for a LTM so you don't compromise your glue with the cure temp To do your radius try araldite 252 I doubt you will find lighter its a bit difficult to work with till you get use to but then its ok Its used in F1 to fill the holes in chassis inserts where pockets are machined out to lighten them Bonding the tubes if you want to go OTT you have Hysol 9394 myself I would use 3m 9323b/a
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