Carbon question.......

[morepower]

After 2 days off with the flu and Monday showing an "Andypath" how to lay up some carbon.. I have done a bit more to the swing arm cover moulds...

1 to 1.5mm of gel coat applied to the wax covered swing arm. It had about 6 to 7 coats of a gloss PVA release agent too....

Used a black pigment to help me see where the gelcoat is applied when making the part...

Now applied 7 or 8 layers of a mix of chopped mat glass and a finer twill weave glass to give a combination of bulk and strength to the mould.

The white pigment is just so it looks nice...
So I hope this time tomorrow I will have removed the new mould from the frame.
Tomorrow I will have added the flanges and PVA to the opposite side and will be ready to apply the gel coat possibly saturday morning. To catch up with work I should have the opposite side laid up by sunday and left for at least 24 hours before I remove the new mould from the frame.

Then the work on mould prep will begin and I have to sand and then smoothe and polish the mould before coating with chemical sealers and chemical release agents too.... I hope by wednesday I could be close to having the first part out of the moulds.

I thought I would give you a bit of a step by step guide so you know what is needed and how long it can take to make a mould. Most think it is simple and quite quick to make a mould so do not see the cost above the cost of materials. I would estimate the cost of materials for all 4 parts with waxes, PVA, resin, glass and flange materials would only be about £35.00 to £40.00 but would take about a full week to make.

[Drunkn Munky]

Make the step by step as detailed as poss please

What i dont quite get tho is this, Once that mould dries and you remove it your left with the perfect shape and size of the swinrarm, I take it you then start laying the carbon for the final piece into the mould, im sure theres more to it than that but you get what i mean yes? So you've laid a few layers of carbon down and the end result is a swingarm cover say 2mm thick? Now this is the bit i dont get, how does that swignarm cover now fit around the swingarm now its 2mm thick as in my head thats now too small to fit

Do you follow what im saying?

[morepower]

Make the step by step as detailed as poss please

What i dont quite get tho is this, Once that mould dries and you remove it your left with the perfect shape and size of the swinrarm, I take it you then start laying the carbon for the final piece into the mould, im sure theres more to it than that but you get what i mean yes? So you've laid a few layers of carbon down and the end result is a swingarm cover say 2mm thick? Now this is the bit i dont get, how does that swignarm cover now fit around the swingarm now its 2mm thick as in my head thats now too small to fit

Do you follow what im saying?

Yes.. If you look at the first images I have put a 1mm thick layer of wax sheet all over the part I am moulding from. This makes the mould 1mm bigger all over so the part can now be 1mm thick and fit perfectly. I then put 6 or 7 coats of a PVA release agent over the wax as the gel coat would stick to this wax (it is not like polishing wax and has a dull surface too) The PVA does add a bit more thickness but it is minimal, possibly 0.1mm or less, but does add some gloss to the surface and will allow the mould to be released from the bike more easily.

The Gel coat only needs to be about .5mm thick in the actual mould but as the part has welds and rough areas the wax is trying to even out the mould would still be uneven so allowing a bit more thickness to the gel coat doe allow me to sand and smooth out these imperfections without getting down to the glass core.

Again this opens up the mould a bit more and gives possibly an extra .5 to .7mm of clearance for the new part to fit over the swing arm. This allows for a bit of the adhesive mastic tape I supply too. If I wanted to make thicker parts I could use thicker wax sheets up to 6mm thick if I need too... It is all about the thickness of the wax sheet you apply and knowing how much material it takes to make up the part to the correct thickness. 1mm of finished part thickness could be 1 layer to 4 or more layers of carbon and glass material depening on the weight of that material. The normal material I use varies from 100gr per M/sq to 650 Gr M/sq so obviously mixing layers with different weights can give you an exact thickness if it really is critical. Also as I dont just do wet lay which is very unpredictable for thickness due to the amount of resin being layed down being uneven. I Vacuum bag all my parts to squeeze out exess resin from the wet part.This does make a better part with an even thickness which will be the same every time if your lay up is the same each time. It also allows me to put a textured surface on the back of the part to give the adhesive something to grip when it is being fitted to the bike..

[thunderace]

Is it feasible to overlay onto existing fairing panels? I'm just toying with the idea of a carbon seat unit. Just wondered if it would be easier just to overlay

[morepower]

Is it feasible to overlay onto existing fairing panels? I'm just toying with the idea of a carbon seat unit. Just wondered if it would be easier just to overlay

What do you mean?
A carbon wrap?
Or make a mould from your existing seat unit to make a new one?

A wrap is possible just need to be sure the surface will not self release the resin as I had to do this with a MX tank and it would just pop off the tank when it heated up and then cooled down again... Wrapping a steel tank or metal parts is better.....

Making a mould is possible but you do need to think how the seat will mount back on the bike. If you try and copy OEM parts they have lugs on the inside that you would not get moulding from the outside obviously... So attaching them again needs to be thought about... But if it was like a race seat unit and you accept it needs to be made to fit then yes you can mould off the part directly.... You need to re-enforce the inside of the part to stop flex and movement. But you can use expanding foam and bits of wood to do that. Yes it is a swine to clean off but if you make a nice part I would assume the original one would be put to one side anyway... You have to remember what ever surface you have on your part will be identical on the moulded part too... So any scratches or stickers would show up....... I would suggest if you do then get the parts coated or lacquered and made as nice as possible...... Or you will have to do a lot of work in the mould to polish it up and get a decent surface finish...

[thunderace]

I meant just making a permanent wrap on top of the OE seat unit. No worries about structural soundness or mounting points. There shouldn't be any major temperature change in a seat unit unless there's an underseat exhaust so I wouldn't have thought self-release would be an issue.

[Drunkn Munky]

Cheers MP that explains it perfectly

[morepower]

I meant just making a permanent wrap on top of the OE seat unit. No worries about structural soundness or mounting points. There shouldn't be any major temperature change in a seat unit unless there's an underseat exhaust so I wouldn't have thought self-release would be an issue.

Well.... The self release problem can happen just through the heat from sunlight as the plastic will heat up and expand then cool and contract more than the carbon will. It will need to get a good bond with the resin on the seat unit. you can only know by tesing a bit somewhere out of sight or on the inside of the part... It will need a good clean with something like a mould cleaner or some cellulose thinners to get rid of any oils or waxes. If the test area works then you need to get some good thin resin to apply. Epoxy resins are good and tough. But although clear when applied can discolour over time with UV light. Polyester resins are not quite as clear but have less problems with UV light. I would suggest you have the seat unit sanded and painted with a satin black paint to act as a key for the resin to bond onto as well.. It will also stop any colour showing through the weave.

You have a few options for the surface finish as you cannot use a clear gel coat for the material to be honest as it is not as clear as you imagine.

The pink one is the "Clear" gel coat the clear one is a special water clear resin that would be great over the carbon but a bit too brittle as a top coat.

So you can use the water clear resin with a final coat of "clear" general purpose gel coat and wet and dry it back to get it smooth then polish it up or you can just use a good general purpose resin and slowly build up layers as it is a lot thinner than gel coat and once you are happy there is enough on the carbon to allow you to wet and dry any brush marks away and polish it up. That will work too.... The other reason for a polyester resin is that is is also a plastic and should be expand and contract a bit more like the plastic under neath......

[Evilchicken0]

...

You can make false tits too !!!!

[morepower]

Nah..... Sorry.... The French bloke beat me to it.......