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f1rob
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Easy to do,wont find many things easier to sheet wax !
First get a base board,make sure its 3mm thick.
don't sit your part on it thou,cut the centre out and place it over your main case sitting on all your fixing lugs
make it a tight fit
then cut a circle of wax out big enough to cover the whole case down past your base board.
place centrally an gently work down in all directions
cut out for a really tight fit on the oil filler housing-don't try to cover the filler yet
As you get to your base board comes the skillful bit ! Cutting it "just" to size
not to much so it ends up short of the base board and not leaving it too long so it bridges and forms a radius corner onto the base board,you want the wax edge butting to your base board perfectly
then I would make a small pattern the exact size of your filler boss to make it longer then cover the filler boss/pattern an butting up to the main wax covering
use heatgun/hair dryer to soften wax if needed
hope these ramblings make some sense
rob
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redeye
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f1rob (12/06/2015)
Easy to do,wont find many things easier to sheet wax !
First get a base board,make sure its 3mm thick.
don't sit your part on it thou,cut the centre out and place it over your main case sitting on all your fixing lugs
make it a tight fit
then cut a circle of wax out big enough to cover the whole case down past your base board.
place centrally an gently work down in all directions
cut out for a really tight fit on the oil filler housing-don't try to cover the filler yet
As you get to your base board comes the skillful bit ! Cutting it "just" to size
not to much so it ends up short of the base board and not leaving it too long so it bridges and forms a radius corner onto the base board,you want the wax edge butting to your base board perfectly
then I would make a small pattern the exact size of your filler boss to make it longer then cover the filler boss/pattern an butting up to the main wax covering
use heatgun/hair dryer to soften wax if needed
hope these ramblings make some sense
robHey, thanks for the reply. So you say it'll conform nicely in one piece. I think I get what you're saying, but that would leave the mould 3mm shy of the fixing lugs. I was actually considering raising the cover off the mounting plate/flange and to get a mould that is a little longer than necessary to allow some trim off (if that makes any sense).
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redeye
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ChrisR (12/06/2015)
Why not just skin it then? All this expense and complexity seems overkill for such a simple part, grind off what you don't want to come through and skin it - simple?? If it's a cover, over the cover and you want to make it separate then just use 2-4 layers of 200gsm (0.6-1mm thk) the curvature of the part will give it stiffness, 3mm thk part! overkill, that's about 15 layers of 200gsm The above may sound a little blunt but I am really confused why you would want to got to all the trouble, expense & time to just make a cover, for what you are putting into it you may as well just remake the part completely No worries, I like the constructive discussion. This is a dirt bike, the cover will prevent scuffing but also add strength to prevent impact punching holes through the magnesium casing. It's a race ender. 3mm won't quite be the part thickness, there will be some adhesive within that thickness. Even then, laying the part straight onto the magnesium cover is a consideration, but I want to make quite a few.
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redeye
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VVS (12/06/2015)
The casing is magnesium and expensive, they take a battering so the idea is to protect the original case with a cf cover that can then be removed if the bike is sold leaving a clean original case.Yup, plus a hole/smashed case will end a race in no time. Thanks for your comments
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redeye
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Hey guys, work and life have been getting in the way of all things important I'm afraid. Here is some progress though on making the plug. Remember, this is the first time I have ever looked at using sheetwax, but I am impressed with how nice it is to use. I ended up cutting piece with paper templates and sticking and forming in place on the clutch cover. By all means comment and provide constructive criticism, I am using this as a test and learning experience and hoping for a working part at the end of it all. This won't be for mass production and I envisage a max of 2 parts made from the mould but I want to learn the correct technique for future parts that would perhaps be made in larger quantities. All comments re. the state of my bench will be met with the same disdain that my bench deserves ;-) I first cut the clutch profile out of 6mm ply and then 3mm acrylic to fit around the clutch housing as a spacer/flange for the mould. This brings the flange up flush with the surface at which I will trim the final part. Laser-cutting the profile  The glue the "'spacers" etc all to a timber board as well as gluing the clutch housing down:  Then fill in the gaps around the flange with modelling clay (not fillet wax available here but I found it reasonably easy, my kids play dough tools have come in handy):  Then start applying sheet wax in sections (I didn't even know that it had a sticky side, which was really handy obviously - such a newby with sheet wax):   Finally filled all gaps with the same modelling clay. This I found was more difficult in terms of removing excess as it stuck to the sheet wax and was not so easy to remove all. I ended up with a few white smears all over trying to get it off. I was quite worried this (as a guess) 0.1mm thickness would show up in the mould and hence the part, should I have been? Anyway, when I decided to wax the perspex flange I noticed the wax sort of helped removing the clay (it didn't react with it, it just lightly dissolved it - hard to explain). I ended up with this as my plug - it is a little "hazy and not glossy, but I am finding it difficult to polish this surface (sticky trying to rub this with a cloth or similar - I think I'll just have to polish this out on the mould - any thoughts?  Next installment in 3 months 
Edit - the last pic makes the plug look quite a lot hazier than it really is. Also, apologies _ can't seem to get the last picture to show right way up.
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redeye
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Group: Forum Members
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Hey guys, any comments or feedback on the above - itching for a "go ahead" from the experts before I mix my gelcoat up.
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Hanaldo
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Your clay fillets could be neater which would save you a bit of work in the mould, but clay is a pain in the ass to work with. Otherwise, you look good to go. The sheet wax is a matt finish, so you will always need to work your mould to a gloss. I'd recommend doing 2 coats of gelcoat to allow for what you remove.
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redeye
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Group: Forum Members
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Hi Hanaldo, thank you very much for your comments!!!! I will take a look at what I can do about the radii/fillets - what do you normally use to shape these? Should I make myself a small radiusing tool of sorts? Regarding gelcoats - gotcha - been reading a little on here and that is a little gem of info that keeps coming up so is definitely part of the plan. Cheers again! Edit - would filleting wax solve all of my problems overnight - I mean in terms of this project  . Maybe I should consider getting EC to send me some if worthwhile.
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VVS
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Coming along nicely and yes the filleting wax would sort it as it's super easy to work.
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Hanaldo
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Group: Forum Members
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Definitely. Filleting wax is one of my favourite products in composites, it is that much easier and nicer to use.
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