Featured 2019 S3 Rs Latest Mod . . . .

Thanks . . . very useful.
I'm going to carry on making my own for now but with a fallback of purchasing one of their extendas to make a mould if I need to
1. I suspect I can fettle the fit of my own using my Sp3RS carbon fenda and improve the fit slightly, whilst ensuring the thing is absolutely central over the tyre, with the correct clearance from both the tyre and my evotech rad guard. In respect of the latter, the length of the extenda will have to be a compromise as the wheel is very close to the radiator and I want to make sure it is right.
2. I can make the extenda in plain weave, which was always my plan so that it will match the existing fender on my SP3RS
3. One of the issues with carbon fibre is how to finish it - most cheap parts are simply pulled from the mould and if needed, given a light polishing. The problem with this is that epoxy laminating resin isn't UV resistant and will yellow with age and also aquire a rouch/powdery surface. . . . . .
The choice is to clearcoat with a 2K urethane which is sprayed on or alternatively use a UV resistant expoxy-compatible polyester gelcoat in the mould. I'm going to try the latter, having now ordered the materials. It should make for a longer lasting finish and eliminate pinholes in the carbon straight out of the mould whilst at the same time, providing a surface which can be cut back and repolished when needed.

The whole thing is overkill but . . . . something of an experiment for me in mould-making and finishing carbon parts because if this works out, I plan to make one or two other bits for the bike as time goes on whilst at the same time acquiring the skill and know how.
Thanks for going to the trouble to post the pictures, it definitely gives me a fallback option if I struggle making a suitable plug and I'm already on Mk2!!

 

Time for an update . . . . I've been busy doing other jobs on the bike but thought I should revisit the extenda and get it finished. At least part of the delay was ordering mould-making kit and all the gubbins I would need for making a mould. . . .

When I test-fitted my first version, I was disappointed to find that it was resting on the tyre at its rearmost point - great for clearance from the radiator but perhaps not ideal!!!
Whilst this might seem like a small problem, the reality meant that I would have to rework the plug almost entirely and so the plan was to epoxy a whole load of polyurethane foam onto the upper surface in order to allow it to be remodelled to the slightly raised profile whilst at the same time, using a permagrit file to raise the underside to give the correct clearance.
It's been a lot of fun with long periods of idleness waiting for epoxy to cure but I'm now ready to apply a final coat of filler, sand, polish and then move on to making the final mould.
One issue with the Speed Triple is the front forks are very upright compared to the rake on my Tiger and so there is the potential for an extenda to clash with the radiator, particularly when fitted with a guard, like mine is. For this reason, I need a minimum of clearance between the extenda and the tyre but at the same time, enough for safety. Furthermore, I plan to make the extenda in such a way as to be rigid so that it resists the tendancy to get "sucked" down onto the tyre at high speed. More of this later . . . . .
Meanwhile, I have attached photos showing progress to date - it all looks incredibly messy but I'm aiming for as near perfection as possible when finished. I've never made a mould before and so whilst I'm not expecting it to be too difficult, I'm very much looking forward to it . . .

 

I’ve spent the last day or two sanding, sanding and sanding.
The plug is now made. I’m happy with the fit and the tyre clearance and the finish is very smooth.
All set now to make the mould. It’s a first for me so fingers crossed.

 

catch up time . . .
I've been delayed once again. Took the S1000RR to have its MOT and mentioned to the guy the bike was A1 except the rear tyre which was near the limit. I guess he didn't like being told because he wagged his willy and failed it on the rear tyre. I asked him on what grounds he failed the rear tyre and he blustered and bluffed about 1mm of tread in the centre . . blah blah. Total nonsense because I checked the regs before I went. I wasn't about to argue because the plan was to get it through the MOT and then change the tyre at my leisure in the next couple of weeks or so but with my hand now forced, I had to get on and change it. Despite being a 190, sports tyres are very soft and so removing and then balancing it wasn't difficult at all . . much easier than the 180 on my Tiger. Anyway . . .
I spent all day yesterday sanding and polishing the finished plug after having given it two coats of laminating resin. The main purpose of this exercise is to achieve a high-gloss, perfectly contoured finish as this is going to be the finish on any guards made by the mould and also, the smoother and more highly polished I can make the plug . . . the easier it should come out of the mould.
So . . .started off with 1500 grit and then 3000 grit, followed by compounding with 3M FastCut Plus and then polishing with ExtraFine Plus and Ultrafina SE. I guess I spent around 8 hours on it in total.
Final job before bed . . . . I waxed the upper surface of my bandsaw table and bonded the plug to it using epoxy, filled in the gaps with filleting wax and bonded on a piece of white PTFE board to make an end plate.
This morning I painted on 6 coats of mould-release fluid, followed by 3 coats of mould-release wax and then applied two coats of "snot-green" gel coat. This needed to cure for three hours until tacky and then on went the epoxy mould putty. I can't say that there's anything very pretty to show for my efforts for now but fingers crossed, when the mould is finally cured at 8.00pm tomorrow night, I can actually crack the whole thing off my bandsaw table, if not and I've inadvertently bonded this carbuncle onto my bandsaw . . . I'm in deep poo!!!!
Of course, if I can crack it off the table, I then have to extract the plug from the mould and I have a sneaking suspicion this is going to prove interesting as there is nothing to get hold of. Plan is to epoxy some "handles" onto the underside of the plug which I can then proceed to "hang" from bodily . . . will see but I'm sure I can get it off!!

This is the plug after sanding, sanding, sanding and then polishing, polishing, polishing



. . . . bonded to the bandsaw table and release resin applied




. . . . one coat of snot-green tooling gel




. . . . . . two coats of tooling gel




. . . . . . epoxy mould putty applied and massaged into shape - 24 hours and all will be revealed or, if I can't remove this monstrosity . . . maybe not!!!

 

Ho hum . . . I managed to get the thing off the bandsaw table but now have a real headscratcher on my hands. How to extract the plug from the mould.
I have a cunning plan . . . . . . .

 

It's a Baldrick special!! If it doesn't work, it's game over. I'm away to stay with my mother for a few days from tomorrow and so won't be doing any more for close on a week.
The plan is to bond some carbon flanges to the inner edge of the plug and then epoxy some wooden blocks to them, leaving a gap in the middle and then having pre-drilled the blocks, simply bolt them together using some 5mm cap-head bolts which are currently winging there way here courtesy of eBay . . gotta work!!

 

It seems we're still on track.
I bonded a couple of carbon sheets onto the underside of the plug but with a 1cm gap between them. These are only around 0.5mm thick and so I reinforced the bond with redux and a couple of extra plies of carbon on the underside.
I pre-drilled two blocks of wood and inserted 4x5mm cap head bolts/nuts and then bonded these onto the carbon sheets before placing the whole shooting match into the airing cupboard to cure.





I was due to wield the spanners post-cure some time tomorrow morning but my impatience got the better of me and I raided the airing cupboard around 10.30pm tonight
I tightened each bolt very gradually whilst looking for any sign of the plug pulling free of the mould . . .nothing. Tightened some more . . nothing!!
After several turns, the bolts were starting to pull through into the wood and I was beginning to curse my luck when . . . "B A N G!!" . . I suspected the partially cured epoxy might have let go but no, on closer inspection, there was a nice little crack which had appeared between plug and mould and it lifted straight out.





The best bit is the plug is totally undamaged and I can make another mould if I screw up and there's still plenty of scope for that!!!!

Next job is to speak to my carbon suppliers - the final extenda will be gel-coated in the mould in order to prevent pinholes but mainly to provide a high grade UV protection. My main concern is how to do a wet layup using 3k plain weave without disturbing the structure and finish of the cloth - carbon cloth is extraordinarily delicate and is prone to distortion during wet layups - I have a plan but more of that later
Feeling rather pleased with myself . . . . . .

For anyone wondering . . . this project is for fun, education and personal enjoyment only. It makes no financial sense whatsoever - cost so far in parts and materials circa £165 and I still don't have a fenda extenda!!!

 

My first Fenda Extenda is currently curing in the airing cupboard but won't be removed from the mould until some time around 6.00pm tomorrow night . . .
I'm really not sure where to start with this lot but bear in mind, the thread is more about showing folks what goes on behind the scenes when carbon parts are made and also, how much work goes into making those neat little trick carbon parts we like to buy . . .
Epoxy resin is not UV resistant. Most parts we buy from eBay are simply pulled from the mould and if exposed to much sunlight, they will lose their lustre over time and the surface finish will become yellowed and powdery. The solution is to use a 2K urethane clearcoat or to gelcoat in the mould. The former is nasty because it contains cyanates and is highly toxic . . the latter is not much better and the fumes are not conducive to good health but on balance, I would rather deal with fumes than a spray mist.
The first job was to treat the mould with six coats of release agent followed by 3 coats of mould release wax and a coat of expoxy-compatible polyester gelcoat. After a 2-hour partial cure, I planned to lay up 4 plies of cloth with two small reinforcement plies, add peel ply, felt and vacuum bag but I fell at the first hurdle.
When I applied the gelcoat in the mould it beaded, much like tipping water onto a newly waxed car bonnet. I cleaned it all up and prepped the job again, which took most of yesterday. I spoke to my supplier who confirmed that rather than buff off the last coating of wax, I should leave the haze on the surface of the mould to give the resin a key - I repeated the process, only to have the same result and another few hours cleaning up and removing the offending gelcoat. Third time lucky . . . I applied several coats of wax and left some fairly heavy swirls on the surface and this time it worked. It will mean the finished item will need flatting and polishing but hey ho . . . . . .
After two hours curing, I laid up four plies of cloth. . . . . .
Carbon cloth is a real arse to work with because it is woven and as carbon is a lubricant of sorts, it is highly unstable and when handled, the cloth distorts and stretches all over the place. This is not desirable from a cosmetic point of view because we look for the carbon weave pattern in our parts to be straight, neat and uniform. Porfessionally produced parts are normally made using pre-preg carbon - carbon cloth, professionally pre-impregnated with a special resin and kept in a freezer and which cures at high temperature. This cloth is easier to work with because the weave remains stable during handling but it requires equipment beyond the means of a retired optician. The solution is to apply a light spray mist of 3M "tack advehsive" to the surface of the cloth and allow it to dry off. I was apprehensive about doing this but it worked a treat and so I duly cut out the 4 pieces of cloth plus the additional reinforcements and set about laminating them into the mould.
The next problem I encountered is that the face of the mould has a ridge across its width where the fenda extenda joins and becomes contiguous with the bike's own fender. Whilst the cloth is very pliable, it does want to naturally follow the shortest route and this means that where it traverses this ridge in the mould, it will attempt to "bridge" it and the only way to achieve the true shape of the mould is to push the cloth into it. Professional manufacturers use vacuum bagging equipment but again, not something your average oyk can invest in and so I purchased a 10-pack of clothing vacuum bags . . . they're the things your missus puts her unwanted clothes in, sucks out the air using a hand pump or the vacuum cleaner and then sticks them in a drawer for the next twenty years or so. The vacuum bags suck out all the air and so keep moths etc at bay but also, serve the function of crushing down the material to about one third of normal size. So, the theory seemed sound but we won't know if it worked until tomorrow night when I break open the bag and remove the fenda from the mould. In theory, it works like this . . . . . . .
A layer of peel ply goes on top of the carbon- this serves to absorb any excess resin which is drawn from the plies under vacuum. It also allows small air bubbles to pass from the plies and through the peel ply. Peel ply is basically fine-woven nylon and won't stick to epoxy resin and so when cured, it is simply torn away from the underside of the extenda, before releasing the extenda from the mould. On top of the peel ply, is laid a layer of bagging felt which distributes the pressure from the bag, whilst allowing the air to be sucked out from above the mould and thus forcing the bag down.
I really don't know how folks make a living selling carbon bits - the cloth for one fenda costs £5.00 and that's without resin or any of the other consumables used but this was never a financial exercise - just as well!!
Anyway . . following pictures go some way to explaining the process - roll on tomorrow night

 

I'm very disappointed. When I debagged the part from the mould this evening, I had a bit of a struggle removing the vacuum bagging materials and then even moreso the extenda but eventually there was a loud crack and out it popped but . . . . .
Although the surface finish is dead smooth with no pinholes, it seems the first ply didn't wet out fully and there are loads of voids between the gelcoat and the top layer of carbon. I think it is recoverable but will involve sanding off the gelcoat and then applying a layer or two of epoxy resin and reforming in the mould before clearcoating . . . hmm. I'm not sure it's worth the trouble to be honest. I might just layup another part in straight forward epoxy, make absolutely sure to thoroughly wet out the first ply and then vacuum bag. I think I'm going to be looking into suitable clearcoats to use but hey . . . it's all part of the learning process :-(

Still, you guys have ostensibly seen how to make parts from carbon and then . . . fail!!
Will post again when I eventually have a part that I'm happy with - it may even be this particular piece if I decide it's recoverable but may just make another anyway to see how it turns out