Hi, My first post after only nearly 2 years after going on your brilliant course. 

I'm going to make some parts for an old scooter where the original plastic is bio-degrading. These parts are non-structural and I'm going to use this project to start to get some practical experience with resin infusion. 

Anyhow, in the first picture below, there are a couple of internal locating tabs. I could make them out of aluminium angle so that there is a lot of surface area to glue the tabs and I can bend to get the exact position after fitting but that seems a bit of a botch. I wondered what would be the best practice way to create these locators such that I could glue or bond them and easily get their angle correct in one go? I imagine that if the tab were made as a simple tongue and stuck with methacrylate, there wouldn't be enough surface area for the methacrylate to hold the tongue for long?. But If I made an angle for more surface area or to be overlaid it might not be exactly the correct angle when stuck down and unlike aluminium, wouldn't be bendable.


Similarly, in the image below, there are locator tabs plus a tube of plastic that takes a self-tapping screw. These tubes tend to split and fail & in the past I've repaired by winding  high-tensile wire & epoxying over. For the replacement panel, I would replace this nastiness with an embedded nut but again, what's best practice to get the nuts and locating tabs in the exact right position?
 
Finally below, a similar sort of problem, this is a suspension cover that pivots about the single bolt fixing. the b side tube that's broken sits over a suspension big nut so that it is pivoted with the suspension arm about the small hole. Should the tube be made of metal for wear & tear's sake? 

The scooter (an Aprilia Habana) is a brilliant design but the non-structural plastic panels are made to fail. 



Finally, if I were to not start the part manufacture with the UV resistant polyester gelcoat (due to being useless at spraying and not having the equipment) but instead took the parts to a paint shop for a UV resistant clearcoat, is there anything I should do different when laying up? 
Many thanks
Darren

Hi Darren,

The tabs and brackets are always quite difficult to do and there is no right  or wrong way.  Your ideas are all fine.  As long as you make the bonding surface  area a good size, then bonding with a methacrylate adhesive is a good solution and plenty strong enough.  

You can salvage complicated shape clips off of scrap parts .  Things like those tubes, you can actually get pre - made plastic tubes which you could bond or laminate into place. Also sometimes you need to use a different kind of fixing for simplicity.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant